James E. Brau

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ORAL HISTORIES
James Brau

Photo courtesy of Kelly James

Interviewed by
David Zierler
Interview date
Location
Video conference
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In footnotes or endnotes please cite AIP interviews like this:

Interview of James E. Brau by David Zierler on May 11, 2021,
Niels Bohr Library & Archives, American Institute of Physics,
College Park, MD USA,
www.aip.org/history-programs/niels-bohr-library/oral-histories/46974

For multiple citations, "AIP" is the preferred abbreviation for the location.

Interview with James Brau, Philip H. Knight Professor of Natural Sciences at the University of Oregon. Brau describes his career-long interest in pursuing physics beyond the Standard Model and his consequent campaign to realize the ILC. He recounts his childhood in Washington, and he describes his early interests in science before enrolling in the U.S. Air Force Academy. Brau explains the opportunities that led him to MIT for graduate school before serving at Kirtland Air Force Base to work in the weapons lab before returning to MIT to complete his PhD where Richard Yamamoto supervised his research on high energy interactions. He describes his postdoctoral appointment at SLAC in the bubble chamber group before taking a faculty position at the University of Tennessee. Brau describes his involvement with SLD at SLAC, and he narrates his involvement with SSC planning while he was transferring to Oregon where he established the Center for High Energy Physics and where he became involved in the LIGO collaboration. He explains the origins of the ILC idea and how his research group joined ATLAS at the LHC. At the end of the interview, Brau reflects on the importance of encouraging public support for fundamental science.

Transcript

Zierler:

Okay. This is David Zierler, oral historian for the American Institute of Physics. It is May 11th, 2021. I am delighted to be here with Professor James E. Brau. Jim, it's great to see you. Thank you for joining me today.

Brau:

Well it's very nice to be with you.

Zierler:

Jim, to start, would you please tell me your title and institutional affiliation?

Brau:

I carry the title of the Philip H. Knight Professor of Natural Science at the University of Oregon. I'm a professor in the physics department and I've taught physics and astronomy at the University of Oregon for over 30 years.

Zierler:

Now I'm intrigued how Philip Knight came to endow a chair in physics at Oregon. What's the story there?

Brau:

Well actually he endowed a number of chairs in the university. And it was up to the university to decide which faculty members should be recognized with those honors.

Zierler:

Did you ever meet him?

Brau:

Yeah, I have met him a few times when he was on campus. For example, there was a reception I was invited to at one point. Various things like that. He's obviously very active. I go to the basketball games and sit across on the other side of the arena from him, and so I see him quite often when he's sitting there watching the basketball games.

Zierler:

Jim, a very in the moment question, and it's one that's purely speculative at this point, but I've been having a lot of fun asking the people I've been talking to over the past month or so, their take on the muon anomaly at Fermilab right now. What's your take on what's going on there? Do you think this is possibly new physics?

Brau:

Well, I think it's certainly possibly new physics. If I had to bet on this, I would bet that it's … there's a theoretical issue that's not resolved. Not the new physics that everybody hopes for, but more in the details of understanding the calculation of the expected Standard Model. There are two theoretical competing classes of predictions on what the value should be. One is much closer to the experimental result, and one's significantly deviant. I think either one of them could be right, and until we sort that out, I think we have to reserve judgement on whether this is a sign of truly new physics or just the complications of the theoretical calculations.

Zierler:

Jim, to what extent does this mean that there's still more to learn within the Standard Model, let alone beyond it?

Brau:

Well, that's an interesting question. It's not so much the physics within the Standard Model. It's just some of these effects are very complicated and in a particular case of the muon, there are lots of-- that's why the G-2 measurement is so interesting; there are a lot of complicated things going on, both from the Standard Model and possibly from new physics. So we have to wait to see what the real outcome is.

Zierler:

To broaden out a little bit from there, just generally in the field, what's exciting that's going on in high energy experimental physics these days?

Brau:

Well, of course my great interest is trying to find physics beyond the Standard Model, and that's why I've devoted a large fraction of my effort over the last several years or even decades, you might say, to trying to realize an electron-positron collider, the International Linear Collider, or ILC. It will give us very, very precise measurements of the properties of the Higgs boson where there's a better understanding of what to expect from the Standard Model than what we're just talking about with the muon. It's much cleaner and because the Higgs mass is much larger, the new physics effects are much larger. It's theoretically what you expect. So if we can make precise measurements, as they've done with G-2, but with the Higgs boson, there's a good chance that we can find evidence of the new physics. And we've studied this a lot, and there are differences in what would happen with the Higgs. If you measured many different aspects of the Higgs boson, you can see different types of new physics appearing in different ways, and perhaps really get a clue as to what's going on.

Zierler:

And in terms of siting, planning, what's the status of where this might happen, this endeavor?

Brau:

Well, the most likely location is in the northern portion of Japan. The Japanese physicists and government have been actively preparing for hosting an International Linear Collider in northern Japan for quite a while. And the International Committee on Future Accelerators (ICFA), which is the organization, global organization, that tries to coordinate activities in high energy physics, has been guiding international plans and efforts towards this. They've recently set up a new team that is working closely with the Japanese, an international team, to prepare for what we refer to as the pre-lab. We're hoping at the end of this year there is going to be significant funding in Japan which would then be followed with international contributions for a pre-lab to work on the details: the design work, the engineering needs that would be prerequisite to actually starting construction of the collider in a few years.

Zierler:

Why Japan, of all places? What's your sense of even the geopolitics behind that?

Brau:

When I first started working on the International Linear Collider-- or it was actually, we called it the Next Linear Collider, over 20 years ago, it was an idea that was coming out of SLAC, the Stanford Linear Accelerator Center. And the hope then was to have something located near SLAC. There were a couple of sites in California that were carefully thought through and proposed. And then the idea was, well, maybe it should go near Fermilab, because Fermilab became the prominent leader in the US high energy physics program, as other labs drifted down in their high energy physics prominence relative to Fermilab. And so there was an effort for quite a few years to try to realize a project near Fermilab.

But ultimately the US, led by the Department of Energy, passed on the opportunity, and the high energy physics community then organized globally, and the Japanese stepped forward and said, "We would like to propose to host this project." Now of course there's a diversity of views in Japan. Some are enthusiastic. There are many politicians who are enthusiastic about this. But there are others who are dubious about it. So it's not yet a decided deal.

But in terms of the geopolitics, the ITER project (the large fusion energy project) was really pursued aggressively by the Japanese, and for quite a few years the US was very eager to help them realize ITER in Japan. And that didn't come to fruition, but I think the Japanese would love to have a globally important, big project that would bring scientists from around the world and be recognized as a center of a prominent part of the scientific community. So that's geopolitics, I would say. And from the US side, the Department of Energy and the Department of State as well, by the way, have really been urging the Japanese to move forward with the ILC, not with any formal commitments of funding at this point, but with an understanding that if they would just make the decision, that the US would be prepared to then decide how to contribute and be partners in the realization of the project.

Zierler:

Jim, one of the big question marks in high energy physics is what role China might play in the coming decades, given its capacity to support basic science and the way that the government might view these large-scale projects as a point of national pride. And so, in what ways might China be a complicating factor with what's going on in Japan, or not, from your viewpoint?

Brau:

The Chinese scientists have been participating and collaborating with us on the International Linear Collider. From the beginning, there has been interest and active participation. At the same time, they have in recent years put forward their own complementary project, which is a large circular collider of a 100km circumference or so, which would allow an initial electron-positron collider that would have similar properties to the International Linear Collider, but restricted in its energy reach. The linear collider is linear to allow us to go to higher and higher energies, whereas a circular machine is limited by the synchrotron radiation effects of electrons and positrons in the ring.

So, their ambition is to build this big ring starting out with electron-positron collisions and then ultimately move forward with proton collisions in the future. Having the ring established, that would be something a decade or two down the road. Similar to what happened at CERN with the LEP e+/e- ring then being converted into the Large Hadron Collider with much higher energy with protons. The Chinese are pushing for this. They've got international collaborators. There are Americans that are collaborating with them, but at the same time they've been cooperating on the International Linear Collider. So it's just a question of who comes forward with the support from the funding perspective to realize one or more of these projects.

Zierler:

Jim, over at CERN, what lessons are to be derived now that we're coming up on ten years on the discovery of the Higgs? In light of what has and has not been seen at the LHC since?

Brau:

From the physics perspective there was quite a lot of expectation that the Higgs would be just the first discovery of additional revolutionary discoveries. And that hasn't come about. We've got the Higgs. We've got measurements of it. We're improving those as time goes on. But the dramatic discovery of new physics such as supersymmetry or other exotic things... heavy gauge bosons or who knows what, that people were imagining had to be there to explain the phenomena that we haven't been able to explain with the Standard Model, hasn't come about. There is of course an effort underway at CERN to increase the total number of events by about two orders of magnitude over the next many years. It's a really challenging goal and it's going to be difficult to achieve, but I think it will be realized after a lot of hard work by many people over that time. And we'll see whether those expectations, you might say, optimistic projections, are realized eventually. It's just where it's a little bit harder to achieve. There are a lot of blind spots in what's been analyzed even in the data so far, and because of the... you can't afford to take all the data, analyze it all. You have to kind of figure out where you look and what assumptions you're going to make about what the new physics is doing and how it's modeled and so forth. There are many blind spots already, and with more data we can hope that something will show up.

Zierler:

And for you specifically, with your research, a question we've all been dealing with over the year-plus, how has your science been affected one way or another in terms of the mandates of remote work, not being able to go in, not being able to see your colleagues in person?

Brau:

Well, the program at CERN has slowed down significantly for sure. And I've also had a small involvement in the LIGO project, which I started at the University of Oregon when the LIGO Scientific Collaboration got started over two decades ago. That's also been hampered and slowed down to some extent. The laboratories have been unfortunately required to really be very careful about how their personnel were allowed to congregate and so forth. So it's delayed things. It hasn't stopped things, I would say. It's just put efforts on a delayed schedule. But a lot of studies continue to progress, because there's a lot of data already available and lots of activity going on analyzing that data. And, of course, that can all be done remotely quite effectively. So significant progress continues, but the goal for acquiring additional data is hampered and slowed down.

Zierler:

Well, Jim, let's take it all the way back to the beginning. Let's go back to Tacoma, and let's start first with your parents. Tell me a little bit about them and where they're from.

Brau:

Okay, my father was from a small town near Tacoma called Yelm. He graduated from high school in Yelm, Washington. My mother grew up in Seattle and Tacoma, in the larger cities. And I'm not exactly sure how they met, but they definitely had a romance before World War II, and got married before the war. After Pearl Harbor my dad volunteered and went off to fight the war. He ended up in Italy. He was first in Northern Africa, and then eventually into Italy after the invasion there. In the meantime, my mother actually joined the service as well to keep herself occupied while he was away.

Zierler:

What service was that?

Brau:

The Air For-- Well, it was the Army Air Corps. Yeah, it was before there was an Air Force. They were both in the Army Air Corps.

Zierler:

What did she do for them?

Brau:

Well, she became a telephone operator. She trained to be a telephone operator during the war. Later she worked as a civilian operator at McChord Air Force Base near Tacoma. She eventually became the chief operator there. That was the old days where they'd have all the plugs and you'd call into the switch board to talk to the captain or lieutenant, and they'd plug it in just so you could actually talk to them. There weren't direct phone lines in those days. She kind of tired of that and eventually moved into bookkeeping also at the Air Force base. She got some training and became a bookkeeper eventually there.

Zierler:

Did your father ever talk about his experiences during the war?

Brau:

Yeah, he did. He talked about it a bit. He was a signalman. He did radio communications. He didn't really see much of the real action. He was more in the communications area. Which was the start of his interest in amateur radio. He got into amateur radio after the war. I remember he had a room at our house where he kept all of his equipment that when we were younger, we were prevented from going near it. But he would hide himself in there and talk to people in Japan or elsewhere around the world from time to time.

Zierler:

What was his profession, post-war?

Brau:

He was using Morse Code. Morse Code is what he did.

Zierler:

Oh I see.

Brau:

Well, he was a hardwood floor man for most of his career. Installing and finishing hardwood floors. First working as an employee of a company, and then he started independently doing that. He got hooked up with some contractors and had a subcontracting business. Some people were building houses around Tacoma and he would get the gigs to do the flooring in those houses. In those days, hardwood flooring was much more popular. Eventually he gave up on that. It was a very seasonal business. It was mostly summertime. In the winters he'd struggle to find any work. He eventually then also went to work at the Air Force base in the transportation section there, but that was after many, many years of hardwood flooring.

Zierler:

Now in Tacoma, was your upbringing more in the city, or in the suburbs?

Brau:

It was in the city. It was in the city. There were four high schools within the city. Mine was Lincoln High School, which is where I... so that's where I went to high school.

Zierler:

What were some of the big employers or industries in Tacoma when you were a kid?

Brau:

Well, Weyerhaeuser Timber Company was pretty big. And the base, the Air Force base, and Fort Lewis. There was also an Army base out beyond McChord. So there's a lot of military there, and there was Weyerhaeuser, and that's kind of what I'm reminded of.

Zierler:

You went to public schools throughout?

Brau:

Throughout public schools, yeah.

Zierler:

When did you start to get interested in science?

Brau:

I think it was a pretty young age. My parents, particularly my dad, would always urge me with the value of mathematics. He was always pushing mathematics. I recall early on it was more the mathematics aspects and then I became aware of the connection between math and science, I guess, and as I worked my way... I mean I have a very fond recollection of one of my junior high school math teachers, Mr. Torgerson, who was great. He was a really a fun guy and a great teacher. In high school, I become even more interested in sciences and tried out different ones. Chemistry (with teacher Royal Leach) looked pretty good. I was interested in genetics for a while.

But eventually I got into the physics course, and that really sold me on physics. I was also actually quite interested in the space program. As I was growing up, I used to subscribe to a magazine about the space program, and I followed that quite closely. I imagined somehow working on the space program. I didn't appreciate basic science so much in those days. The distinction between basic science and things like space and engineering were unclear. I was thinking that space was the theme that might be my interest. And, of course, astronomy was related to that.

Zierler:

When you were a kid, did the way that President Kennedy talked about the space mission, did that resonate with you?

Brau:

Yeah, definitely. Yeah, definitely. And of course, that whole decade with all of the different missions that were happening. John Glenn’s flight was exciting and then eventually leading up to Neil Armstrong's first steps on the moon and so forth. Yeah, it was very exciting, that whole period.

Zierler:

Jim, when you graduated high school, was the draft something you needed to contend with? Did you consider enlisting at that point?

Brau:

Well, the draft was not an issue for me. I graduated in '65. In '64 things started to heat up with the Gulf of Tonkin incident, and there was lots of talk about what was going on. As I recall how I ended up going to the Air Force Academy, it was a mixture of my family's history with the military and my interest in space. I envisioned the Air Force Academy as being related to the possibilities of getting involved in the space programs and related areas. It was viewed as being a really good education, at a fairly low cost. [laugh] So yeah, but the draft ramped just a little bit after that, when I was already at the Air Force Academy, and a draft lottery was held in 1969.

Zierler:

When you're already at the Academy during this period, is there talk about being shipped to Vietnam, or that was not in the cards for your program?

Brau:

Well, certainly as a cadet, you're not vulnerable to that, because you're a student and learning, until you graduate. Depending upon what career path you pursue, you may or may not end up there. A large fraction of my classmates did because they were pilots. I had poor eyesight, so I wasn't actually qualified to be a pilot. I had to get a deferment-- not a deferment. I can't remember what they call it now. I had to get a--

Zierler:

A 4F?

Brau:

No, not a 4F. It was an academic waiver for the eyesight requirement. If you were ranked in the top 10% of the incoming class, you didn't have to have 20/20 vision. I didn't have 20/20 vision, much worse. I wore contact lenses. Anyone in the lower 90% of the class had to be pilot qualified. But they recognized the need to have scientists and other people who had more intellectual capabilities that may not be able to fly a plane. And so I was never pilot qualified and never in the position therefore of pursuing that. But most of my classmates were-- the reason they were there was to become pilots. As I said earlier, the reason I was there was more related to my scientific interests, which evolved quite a bit while I was at the Academy, I must say. But they did go to Vietnam, most of them did. Yeah.

Zierler:

Jim, for so many of your peers, in your age bracket, your generation who were undergraduates in the late 1960s, in places like Berkeley or Chicago or Harvard, there are always stories to tell about anti-war protests on campus and things like that. Was any element of that whatsoever present at the Air Force Academy when you were there?

Brau:

I don't remember much at all, because cadets were dominantly very loyal people. They didn't really have that incentive. It was very conservative, I would say.

Zierler:

That's to say that even if people did have misgivings about the war, they would have kept it to themselves?

Brau:

Well yeah. I mean there were a few people who questioned it, but it was still a little early in the whole thing in a way, because I mean the last year I was there, I guess things started to get a little more questionable, but by the time I graduated in '69, I think a lot of the activity was starting to heat up in the '67-68-69. But no, generally speaking, by and large, these are people who are not inclined to be protesting national policy or anything like that.

Zierler:

Jim, how integrated was the Air Force Academy when you were a cadet? Were there Black cadets that you remember?

Brau:

There were some Black cadets, some in my class. And there were also... I remember in particular one white cadet who was extremely prejudiced, which shocked me. I mean I grew up with and around African Americans. My high school was populated by many African Americans and some were close friends. I had an outstanding mathematics teacher, the best math teacher in the high school, perhaps in the city, Cornelia Lasley, was Black. For me it was not a big deal. I didn't actually realize the issues of race relations so much.

But then at the Academy, of course, there was a diversity of people from all over the country, and especially many of my classmates from the South. I was sort of shocked at some of their reactions and attitudes. I remember this one incident where there was a… the way it is there, when you're a First Classman, which is a senior, you're really in control of the situation, and if you're a “doolie,” we call them doolies, the Fourth Classmen, or the freshmen, you're nobody. You're basically nobody. And I remember there was this First Class (or senior class) Black guy who was a very nice guy, very decent guy and everything, but boy, some of those Southern white boys, they didn't like that situation at all. [laugh] And to me it was kind of shocking at the time, but now I think about it, it's just amazing, yeah.

Zierler:

Jim, in physics as an undergraduate, what opportunities were there for laboratory experience, or exposure to what would ultimately become your areas of expertise?

Brau:

I had a really good opportunity, because one of my professors there, Ray Kelley, had a small accelerator. We were irradiating samples. I was doing research with him irradiating samples and then measuring the radiation, the disintegration of nuclei, and he taught me a lot about experimental physics there. I also had an excellent-- three faculty members there stand out to me. It was John Ahearne, was an excellent theoretical physicist who taught me quantum mechanics I guess for a couple of years there. And John Balogh was a very, very good physics instructor. And then Ray Kelley, who I mostly worked with experimentally.

Zierler:

Jim, when you graduated, what were the expectations in terms of ongoing service?

Brau:

There was a-- I had a commitment for five years of active duty out of the Academy. And by the time I graduated from the Academy, I was pretty clear that I wasn't going to go on to a career. My interests in science and my understanding of my interests in basic science were clear to me. I wanted to free myself of the constraints that would be imposed by a career in Air Force. But I had that five-year obligation, so I had to pursue that. I remember there was pressure put on me to go to navigator training after graduation. I wasn't pilot qualified, but there was some pressure to become a navigator. I actually took navigation classes as an elective while I was there, because it was just a fun thing for me to do. We'd fly around the country, keep track of where we were, and I just found it a nice distraction from the everyday grind.

But I had no interest in becoming a navigator. I wanted to be a scientist. And so I managed fortunately to get a fellowship from the Fannie and John Hertz Foundation out of the Academy to go to MIT for graduate school, and the Air Force allowed me to go there. Initially I went there expecting to go for a PhD. But what I realized was the Air Force was going to increase my obligation to service by a large factor if I stayed at MIT for a whole PhD, and so after I got there, I reconsidered the tradeoffs between getting a PhD now and then being locked into the Air Force for the next 15 years versus getting a Master’s degree, going back to the Air Force, getting my time in, and then going back into graduate school. And so that's the direction I took at that point. But I established some good relationships with MIT while I was there that one year getting my Master’s degree, and so that really put me in a good position when I got out of the Air Force to go back there and resume my studies. And the Hertz Foundation was gracious enough to renew my fellowship when I went back after I got out of the Air Force.

Zierler:

How well-prepared did you feel relative to your classmates in the courses at MIT?

Brau:

I felt very well-prepared. I really did. And I think it's because of the three faculty members that I referred to earlier. They were really very good in preparing us. Particularly John Ahearne, but also John Balogh. And we had some nice small physics classes. And my math-- I was a double major at the Academy. I also had a math major. In fact, I took some graduate courses in math. I could have gone to North Carolina State for a Master’s in math in a, I don't know, eight-month program or something based on my math studies at the Air Force Academy.

Based on my physics courses I also qualified for the accelerated Master’s physics program at Ohio State. And that was because I went in-- my high school was very good, too, because I went in and I exam-ed out of a whole bunch of the introductory courses in math and the sciences. For example, in chemistry, normally, all the cadets had to take a full year of introductory chemistry. I only had to take a half a year of accelerated material. I also jumped ahead in math. I have to give credit to my high school for preparing me, too, because I got a good jump on things at the Academy. And then, fortunately, there were the faculty members who allowed me to really develop to my full potential. So when I got to MIT, I felt I fit in pretty well.

Zierler:

Jim, were you fully into experimentation at that point? Or were you open to a career in theory also?

Brau:

I think I understood I was an experimentalist. In fact, I remember I got to MIT about a month before the courses were to begin for the fall term, and I went around interviewing faculty members to see who I might be able to work with. And they were all experimentalists. I didn't talk to any theorists. I knew I was going to be an experimentalist. I wanted to do experiments. I didn't want to do theory.

Zierler:

How parochial was your viewpoint of experimental physics at that point? In other words, did you know all of the exciting things that were happening at the national labs and at CERN at that point?

Brau:

I would-- no, not really. No. I was leaning on the faculty to guide me on that, and yeah, it took time to understand things. There was a big revolution in '74, the October Revolution. That was right after I got back to MIT.

Zierler:

I believe the November Revolution.

Brau:

Ah, November. I'm sorry. November Revolution.

Zierler:

[laugh] The October Revolution is a very different thing.

Brau:

Yeah, yeah, yeah. Sorry. So, I'd just gotten back. That was my first year back after I'd done my Air Force service, and all this business with charm started coming out. I hadn't anticipated that. I was learning. I was learning on the fly about that. I mean, I'd studied the... I was very interested in quarks. I remember my senior year at the Academy, I wrote a report on quarks and kind of had figured out by then that I wanted to do particle physics, which didn't match very well with the needs of the Air Force.

Zierler:

[laughs]

Brau:

So I was pretty aware of what was going on, but charm was something completely new at that November Revolution. [laugh]

Zierler:

How did you connect with Irwin Pless, and what was he working on at that point?

Brau:

Well basically what happened was, I went around and talked to a number of faculty members, and I realized that I wasn't going to be able to stay for the PhD. And Larry Rosenson was very helpful there, and I talked to Larry and said, "Look, I really need to find a way to get a Master’s degree so I can go back and get my Air Force obligation out of the way, and then I can come back and do the PhD." And he suggested I talk to Irwin. He said Irwin is really good at this sort of thing. So that's how I connected to Irwin. I went and met with Irwin and he was very helpful and very willing to work with me and to bring me in. He was leading a group developing and using PEPR (Precision Encoding and Pattern Recognition) for computer-aided measurement of bubble chamber film. We worked on a very interesting analysis using something called the prism plot, which is a way of looking at events and studying them. And it was a lot of fun. Ended up with a publication out of it.

Zierler:

What did you want to do next after MIT? Given your understanding of how limited your time was there.

Brau:

You mean after the PhD or after the Master’s?

Zierler:

No, after the masters, when you could only stay for the year.

Brau:

Yeah, the Master’s. Well in the Air Force, what I had learned when I was at the Academy was the place to go to really do physics in a sense was Kirtland Air Force Base, the Air Force Weapons Laboratory. There are real physicists there, and they were doing things that were real physics. Things of interest to the Air Force, but they involved physics. But I didn't manage to get assigned to Kirtland. I got sent to Holloman Air Force Base, which is in the same state, in New Mexico, but in southern New Mexico. The group that I was assigned to was a test facility to test guidance systems: accelerometers, gyroscopes and a variety of things. And it happened that someone in that group before I went there had gotten the position reclassified as a physicist.

So, it wasn't really a physics position, but it was classified as a physics position, and I ended up being assigned there. And I was really unhappy about it. I did my job and I was basically just carrying out calculations that were pretty routine and nothing particularly exciting. So, from the day I got there, I made an effort to move. And what I did was to contact my former professor, John Ahearne, who had moved to the Pentagon. He was in a very prominent position at the Pentagon by then, and he helped me figure out how to get reassigned up to Kirtland in Albuquerque. I only spent about a year at Holloman before I got re-assigned to Albuquerque to the Air Force Weapons Laboratory. I went there and I joined a group led by Greg Canavan. And I had a really successful period of time there working on the variety of theoretical-- it was theoretical physics group, actually, even though I thought of myself as an experimentalist. It was a theoretical physics group. We did lots of different calculations of interest to the Air Force.

And a lot of things having to do with lasers and the interactions of lasers with material. And one of the things I got involved in was the electromagnetic pulse, which was a threat to the strategic weapons systems, because high altitude nuclear weapons could send out an electromagnetic pulse that could wipe out the communications of a large fraction of the strategic weaponry. And this was an interesting effect that the British had actually realized, and then the Air Force started getting worried about it. The silos had been set up in a way where all of the connections were just the perfect antenna to absorb the radiation from such a device and just render all of the silos [laugh] inoperative. And so this was something of great interest at the time, and involved understanding of the physics of what goes on when the explosion occurs, and all of the radiation comes out and how it generates this current, electric current, that then creates a very intense, short pulse. So I was involved in that. A lot of laser things. It was an interesting experience, I must say.

Zierler:

Jim, given how fully ensconced you were in a scientific environment that was also the Air Force, did that cause you at all to reformulate any earlier ideas you had about leaving military service and pursuing a PhD? Or you always looked at this as a placeholder, intellectually?

Brau:

Well yeah, definitely. I felt it was an obligation. It was my duty to do. But I had no doubt about the fact that I wanted to go into fundamental research. Particle physics was my first interest. I remember people telling me at the time, and there were very few positions open, when you looked at Physics Today where previously there had been just pages and pages of opportunities, there were very few opportunities in those days. People were telling me, "You're going to waste your time going off to graduate school at this point." But I felt that I wanted to do that, and just see where it led. And it was my intellectual interest in particle physics that drove me. And I had no doubt about it during those years.

Zierler:

Did you keep up your contacts at MIT at all, and was that what was key to you going back for the PhD?

Brau:

Well, I did maintain my contacts, yeah. At some level. And when I was close to going back, yeah, I went back to the same group.

Zierler:

Did you consider elsewhere, or it was always going to be MIT for you?

Brau:

It was always going to be MIT, yeah. [laugh] That's because I'm a really avid Boston Red Sox fan.

Zierler:

[laugh] Really? All the way from Tacoma? How did that happen?

Brau:

Seriously. Well, when I grew up, there was no West Coast baseball.

Zierler:

That's right.

Brau:

No major league baseball on the West Coast. And there was this guy, I don't know if you ever of him, named Ted Williams?

Zierler:

Of course. Of course.

Brau:

[laugh] And so I was a baseball-- I played and collected baseball cards. I mean I was a sport-- I guess going back to my interest in math, a lot of that interest was so I could calculate batting averages. [laugh]

Zierler:

Uh-huh.

Brau:

That was part of it. And anyway, I collected baseball cards, and I discovered Ted Williams through these baseball cards. And I remember I wrote him a few times, and I got these autographed photographs of him back actually. So that's what got me interested in the Red Sox. And of course, like I said, that was before the big move to the West Coast by the Dodgers and the Giants.

Zierler:

Jim, coming in from having this weapons laboratory experience, you had a lot more perspective, so to speak, than other people that may have been coming in just with the Master’s degree. Did you sense that when you entered the PhD program? That you may have been at a little bit more of an advanced stage in life?

Brau:

Maybe. I don't think it was that way. Not so much. When I went back, there were still students there that I had been with when I first went there. There were a couple of graduate students that I had entered MIT with, in our group, at the same time. The three of us then-- in fact, there were four of us that entered that group at the same time (Austin Napier, Mike Hodous, Pierre Trepagnier and me). When I returned they were there still and they had matured as well. In fact, they knew the ropes at MIT better than I did by far. I was leaning on them as much as they were leaning on me.

Zierler:

How did you go about developing both a thesis topic and a graduate advisor to work with?

Brau:

Well, so Richard Yamamoto became my advisor, and I really respected him enormously. He was a great advisor. He was working very closely at Fermilab to develop a hybrid facility bubble chamber with downstream and upstream wire chamber detectors. He was going out to Fermilab regularly, and Irwin suggested that I work with Richard and so that's how I made the connection with him, and we started working together. That worked out really well, because my physics interest then was on that experiment at Fermilab. And I went out there for some periods of time to live out there and support the facility. MIT was building that facility and then sharing it with other groups. There were other experiments that would come in and use the facility, and then we would have it for our own data as well, and there were different configurations that were arranged. And so as graduate students, we were supporting that as well as collecting our own data.

Zierler:

Jim, what were some of the major research questions on this experiment at Fermilab at the time?

Brau:

Well, my particular question was just on the details of high energy interactions, and I was just [laugh] I guess I wasn't so aware of the theoretical issues as much as I was interested in the details of what happens in the interactions. What is the distribution of particles? And we were of course, the rapidity was a measurement that we'd make, and then the different charge states and where the positive charges were and the negative charges. It was really more just a collection of data. And then I created some random models. My thesis had some various random models that would give one result or another. It wasn't so much based on theoretical considerations, as much as it was on, well, if this is going on, and you randomize this, this is what you'll see. And if you randomize that, that's what you see. And then I found a particular parameterization that matched the data. And yeah, that kind of sold. I mean, the theorists that looked at it said, "Well that's interesting. We should try to figure out why it's doing that." I said, "Yeah, why don't you do that."

Zierler:

[laugh]

Brau:

"I've got better things to do." [both laugh]

Zierler:

Jim, in the late 1970s, at the time, where was the Standard Model at this point? Was your sense that it was already completed? That it was on the cusp of completion?

Brau:

It's hard for me to recall exactly. I wasn't as much aware of that myself as... So when I went off to my postdoc at SLAC, there were two experiments I worked on. One was a baryonium experiment (led by Vladimir Chaloupka) where we were using anti-protons to try to produce anti-proton-proton combined states to various baryonium states. There was a lot of pretty sketchy data that indicated that there were various things going on. Maybe four quark states, for example, that-- And so I started working on that experiment, which is not exactly something you think of in terms of the Standard Model. But the other thing I was really interested in doing when I went there was the photoproduction experiment of charm. Charm had now become quite a deal, and by '78 we were going to measure the lifetime of the charmed particles with photoproduction. And that's what we did. So again, yeah, the Standard Model came into play, but I don't think I was thinking of it in terms of the Standard Model, in my little corner of the world. It was more like how can we explain the lifetimes of these particles? And then these other quarks started showing up? The b quark shows up and things start to get pretty interesting.

Zierler:

Jim, for your thesis research, what were some of the major advances in theory that may have been useful or served as a guidepost for your research?

Brau:

Oh boy. Ah. For my thesis research? I don't-- I can't remember exactly what was... there were, it was the structure of these interactions and how multiplicity distributions, for example when you bang 147 GeV proton or pion into a proton, what's the number of particles that comes out and why?

And so people were trying to figure this sort of thing out. And then of course my particular interest as I said earlier was in then what's the distribution of the different charges in this, in how they spread out? And how they're associated with one another. Things like that. But in terms of QCD, it was just around the corner; it was starting to be in experimental people's lexicon. And calculating these things was not something that was very commonly done. It was more phenomenology, getting the data, and then maybe it will lead to the next understanding of what's going on. I think that's the way we were thinking of it. There were theory talks on QCD.

Zierler:

Jim, besides Yamamoto, who else was on your thesis committee at MIT?

Brau:

Bob Jaffe and Larry Rosenson.

Zierler:

Anything memorable from the defense?

Brau:

Well, [laugh] it was pretty straightforward. I was pleased that Jaffe thought what I had done made sense and was reasonable even though it didn't have this deep theoretical motivation. It was more phenomenology. Yeah. I remember the day very well. I remember the event. I think it was pretty straightforward.

Zierler:

What postdoc opportunities were available to you besides SLAC? What was compelling at that point?

Brau:

Well, there was some interest from Fermilab neutrino program that I was asked to consider it. But as a West Coast guy, I really liked the idea of getting back out on the West Coast. So that was part of it. It wasn't like Fenway Park brought me to MIT; it was time to go back to the West Coast. I mixed my personal life a lot with my scientific life.

Zierler:

What group did you join when you got to SLAC?

Brau:

I joined this bubble chamber group, and Joe Ballam was the head of the group. He was also associate director, or research director, I guess, really was his title. He had really recruited me. I think I told Dick Yamamoto that I wanted to go to SLAC, and he got in touch with Ballam. Because of course, they're bubble chamber people. They knew each other quite well. When I went out to interview, I remember that Ballam was pretty engaged in trying to interest me in his group. They had a process there where you go around and interview with all the different groups to see if there's a match between you and them. And nothing else really panned out. I felt very comfortable joining that group, and the bubble chamber. I had good background in that. And so that was a good match for my graduate school experience.

Zierler:

Jim, what was the interplay between theorists and experimenters at SLAC, at least from your vantage point as a postdoc at that time?

Brau:

Well, I went to a lot of seminars in the theory group upstairs. I was quite interested in learning what they were doing and what they were interested in. So... and they were helping us to think about our experiment of course. But there was a lot of give and take from the theorists. I remember Fred Gilman in particular was very accessible and very helpful in various theoretical questions.

Zierler:

What was your sense of the overall intellectual environment at SLAC?

Brau:

Well, in those days it was very good. The research groups were, from my lowly perspective, I thought that there was a lot of opportunity to drive the research program and so it was not top-down so much. It was really driven by the groups and their interests. And of course, you had to go to the EPAC (Experimental Program Advisory Committee) and argue your case on all your different goals and get signed off on what you wanted to do. But if you had good ideas and good ambitions and good strategies, there were good opportunities for pursuing the different physics directions.

This photoproduction effort was really a fascinating technical thing, because we were shining a laser into the linac, and then bouncing the photons from the laser off of the high energy electron beam. You had a 30 GeV electron beam and a low energy laser, and all of a sudden comes back a beam of 20 GeV polarized photons. And those were then directed to the bubble chamber, which was quite far away. And we were actually doing this photoproduction, and then George Kalmus and his group from Rutherford Lab came to the lab and said, "Well, we can put in a high-resolution camera on your bubble chamber to see the decays of these charm particles." And so that evolved... the experiment evolved significantly as a result of that innovation that came out of Rutherford Lab. That group included two I worked closely with, Boda Franek and Dave Kelsey.

Zierler:

What were some of the technical challenges as you were figuring out how to build the bubble chamber facility?

Brau:

Well, my particular responsibility was on something called the Lead Glass Columns. The senior member of Ballam’s group, Ken Moffeit, asked me to assume that role. There was a bunch of lead glass blocks that had been used for previous experiments, and we inherited this lead glass and then had to reconfigure it particularly for the photoproduction experiment. One of the key things there was to have two stacks of lead glass with a vertical gap between so that as the photons came through the bubble chamber and created electron-positron pairs and then split off in the magnetic field, they would go down this gap. We built this up, and it was a lot of work.

I remember building this thing. One of the SLAC physicists, Roger Gearhart, was a great help on this, as well as SLAC engineer Charlie Hoard. And then once it was built and moved into the experimental area I was the lead SLAC physicist with collaborations from university groups actually. From University of Tennessee and Duke. And I'm probably forgetting others that were collaborating with us on that. Florida State, MIT, and others. SLAC group members Clive Field and Terry Carroll also helped. We then made it work, and it was challenging to make it work extremely well, I have to say. Because it worked a lot better in our experiment than it had on the previous experiment. We were measuring the gamma rays out of the bubble chamber, and then being able to add those into the event reconstruction, which was something that hadn't really been done before.

Zierler:

Were you publishing a lot during your postdoc time?

Brau:

A little bit. Not a whole lot. Not-- I wasn't driving publications. There were some publications in the group, and I certainly wrote up a paper and published a paper about this lead glass effort. But that was kind of late in the process. But I did collaborate on other papers.

Zierler:

Did you get to interact with Panofsky at all?

Brau:

I did a little bit. Yeah. I would see him at seminars and in various... before the colloquium and, because they had a weekly colloquium and there was always a gathering there of staff and so forth. And yeah, so I saw him quite a bit actually. He was quite an impressive person.

Zierler:

Did you ever give consideration or was it available to you to turn the postdoc into a staff position at SLAC?

Brau:

Well actually, I was offered a faculty position my last year at SLAC. I was considering that. And then I decided on going off to University of Tennessee instead. It was a hard decision. I mean it was attractive to stay at SLAC in the faculty position. There were other universities. I won't get into the details of this, but I remember one place I went to, they said, well, they offered me a faculty position and said, "We've never had a-- or it's been something like 30 or 40 years since any of the junior faculty members got tenure here, so you've got to keep that in mind when you decide whether or not to accept this position.” [laugh] That was Harvard.

But yeah, SLAC offered me a position in the faculty, and I just decided that I wanted to go to a university that was a real, true university. I ended up going to University of Tennessee; I'd become quite close to Bill Bugg, the physics department head. We worked closely together both when I was a graduate student and also on the photoproduction experiment with the lead glass. He was quite involved in that. And I respected him a lot, and so I decided to go to University of Tennessee, and it was a good decision at that time in my life.

Zierler:

Now that was an offer with tenure, in 1982?

Brau:

No, I was, let's see, what was the deal on that? It was an associate professorship. Yeah maybe it was with ten-- I don't think it was with tenure the first year. I don't remember exactly when I got tenure, to be honest. It might have been. It might have been with tenure. I can't remember for sure. Lee Riedinger was acting Physics Department head at that time, as Bill Bugg was on sabbatical.

Zierler:

What were some of the--

Brau:

But it was an associate professorship for sure.

Zierler:

Were there any sports or geographic affiliations that drew you to Tennessee?

Brau:

Not directly. I mean I certainly followed the sports once I got there. It's quite an active thing there, and I got interested in it and followed it quite a bit. But it wasn't something that was a factor in my decision. The decision was more based on, well, it was to be honest, it was somewhat based on what would be best for my family. And as I said earlier, my personal life has been a big factor in my choices in what I've been doing. In addition to my intellectual interests. I didn't let that stop my intellectual interests, but it was I would say the family. I thought it was a good move for the family, and that was probably a big part of the decision.

Zierler:

Now you accepted the job at Tennessee fully understanding that SLAC would be front and center to your ongoing research agenda? That was part of the consideration?

Brau:

Not completely, because at that time there were beginnings of thought about the SLAC Linear Collider, the SLC. At SLAC that was starting to be envisioned. I remember Burt came and talked to our group one time about-- Burt Richter, about this idea. But it was only after I got to Tennessee that I started to think about the future for the Tennessee group. And I really considered both the SLAC Linear Collider, and also the program at Fermilab with the CDF experiment, and D0. I actually contacted the people at D0 about the possibility of joining that experiment, at the same time I was discussing with people at SLAC about SLD. It could have gone either way, I would say, at that point to be honest. But SLD invited us in first, and it was a good match.

Zierler:

And what was compelling to you about SLD at that point?

Brau:

The Z boson, in measuring the properties of the Z boson, and again seeing if the Standard Model can hold up. And yeah, so that was… it turned out to be a great experience. I did a lot of interesting things on SLD over the years from compensating calorimetry to the luminosity monitor with silicon tungsten calorimetry and worked on the CCD vertex detector. So there were quite a few very interesting technical things in addition to the important physics that we were doing.

Zierler:

Now, did you go to SLAC weekly? Did you go for blocks at a time with sabbaticals? How did that work out?

Brau:

Well so what I would do is go there once a month, and we had a week, an SLD week, so I would go there I think for a good fraction of the week. Maybe I would go for just three or four days. I can't remember for sure. But I always managed to set up things at the university so that I could do that. I was flying out there every month.

Zierler:

Who were some of your key collaborators on SLD?

Brau:

Well certainly Marty Breidenbach and Charlie Baltay, who were the spokespeople for the experiment. Dave Hitlin, so when I -- they were going to build a uranium liquid argon calorimeter and when I first joined SLD, I was given the assignment of understanding the optimization of the uranium liquid argon calorimeter. I started-- I worked with Tony Gabriel at Oak Ridge, who had developed these simulation codes, and I started running these codes and trying to model the performance of uranium liquid argon, which was compensating. The idea had come out of Bill Willis's work that you could compensate the resolution of hadron interactions by the radiation from the uranium.

There were some experiments that had then demonstrated this. Some with-- well, the first one with liquid argon, and then later with scintillator. And with these calculations I was doing, our liquid argon calculations weren't showing this effect at all. They were basically not showing this effect. And it really bothered me a lot. I couldn't figure out why I couldn't get this to work out. I remember we had a-- but what I found was with the scintillator, you could get the effect because the scintillator was very responsive to the neutrons that are coming out of the uranium, and so you get an enhancement in the signal when you have a large amount of energy loss in the interactions in the uranium, which balances out the resolution.

So, with scintillator sampling, you could get the effect. And yeah, so I remember we had a-- I started talking about this in the collaboration, and a lot of people thought I was crazy and it was kind of poo-pooed and everything. But Dave Hitlin was in charge of the calorimeter group, and he actually took it very seriously and listened and then we had a test beam program set up, with some prototypes.

And lo and behold, it was all demonstrated properly, and so as a result of that, and then Charlie and Marty and Dave and some others realized that we weren't going to benefit from having uranium, so we switched the calorimeter over to lead. Mike Shaevitz from Columbia was also involved in this whole assessment at the time. So those were some of the people, the key people during that era. And then I was given responsibility for building the luminosity monitor, and that became a University of Tennessee, University of Oregon collaboration. It was during my move to Oregon. That was Bill Bugg collaborating again. Eventually with the CCD vertex detector, I was asked to manage that upgrade project to 300-million pixel vertex detector. Chris Damerell was the key guy on that project; he was from Rutherford Lab. I worked closely with him, and a number of other people. The CCDs were produced in the UK. We set up a chain of operations in the US with Frank Taylor at MIT, Charlie Baltay at Yale and others to complete the work with different groups doing different things.

I took a sabbatical to go to SLAC to get that started, and then-- well first I commuted and part of the reason I took that project on was I had been involved in the SSC prior to that, thinking I was moving over to the SSC from SLD. And then when the SSC collapsed, and I cleaned out my office and was looking for something to fill up my space with again, Marty asked me if I would take over this management project. I started going to SLAC again on a more regular basis, and ended up going there on a sabbatical to manage the project. So those are some of the key people I worked with over those years.

Zierler:

Jim, how did you get involved with the SSC planning?

Brau:

Well, it was natural when I went to Oregon and I was thinking about the future. Oregon recruited me to come and start an experimental high energy group. There hadn't been one there. And it was kind of--

Zierler:

Ever, or in a while, there hadn't been one?

Brau:

There was a nuclear group. But not an experimental high energy group. There was a very good theory group there led by Dave Soper, Rudy Hwa, N. Deshpande, Michael Moravcsik and Paul Csonka. And I'm probably forgetting some, but they had a strong theory group, and as the SSC came on the scene, these theorists at Oregon thought “we're going to be left out of this if we don't get an experimental group going.” They started looking for someone to start an experimental group, and I had been at Tennessee for about five years at that point, and I thought it was interesting to contemplate going back to the West Coast again. I found out about this. I was actually at a workshop and I learned from Deshpande that they wanted to start this group.

So, I applied for it and then negotiated how we would move this group off of a single investigator to something [laugh] more viable. I went there with the idea of there was no obligation that I'd go to the SSC. In fact, when I went I was really talking about a linear collider. We were already talking about the Next Linear Collider, and I sold the future of the experimental group as being possibly in a number of directions. There was no obligation to the SSC, initially. But after I got to Oregon, the SSC was taking off to such an extent that it was just natural to become part of that and join it. It was just going to be the dominant thing in the US. I started going, and Mike Marx at Stony Brook called me up. I had known Mike as a graduate student at MIT. We weren't in the same group, but we would hang around the IBM computer at the same time and chat about various things. We were acquainted at that point. He called me up and invited me to consider working with him on an experiment at the SSC; that's how I got started. I was already thinking about it, and then that looked like the right direction to go. So, we worked together for quite a while on putting together one of the competitive experiments, which we called EMPACT (electrons, muons, partons with air core toroids).

Zierler:

Jim, from your vantage point, what was so compelling about the possibility of SSC and the kind of physics that could be done at the energies envisioned?

Brau:

Well, we were envisioning the Higgs boson as being something that we would discover, and yeah, so it was designed to make sure that we did cover the range of possibilities where the Higgs boson would be. If the Higgs boson existed, we would find it because it had to be below about a TeV. And if it didn't exist, we would confidently rule it out. So that was-- and then all of the other things that we've talked about and what the LHC is hoping to do, was all more uncertain, but the Higgs was the pretty certain thing that we were going to be able to rule on, one way or the other.

Zierler:

What about supersymmetry? Was this on your radar at all during this time?

Brau:

I think so. People were talking about it. And, yeah, it was something that people speculated on. And, you hear about it, you listen to the talks, you find it a nice mathematical concept, exciting thing if nature went that way. It's quite interesting, yeah.

Zierler:

The offer to come to Oregon must have been particularly compelling because you had the opportunity to build a lab from scratch.

Brau:

Yeah, that's true. I mean again it was personal also because of my getting back closer to my family and the Northwest, and then I felt no pressure from the faculty. I had these discussions with people at Oregon before I came here. I felt no pressure. They wanted a group, period. Just lead an active group. I think we far exceeded their expectations for what would be realized, but the fact that they set reasonably modest expectations made this very comfortable for me.

Zierler:

And in terms of the research, given the fact that you were building something from the ground up, what were you interested at that point intellectually, scientifically, that may have influenced the way that you put the lab together?

Brau:

Well, I was certainly interested in pursuing SLD on the short term, and eventually the SSC on the longer term. That was the vision at that point. We had a-- with those two things, SLD going well and we had a good role in that with the hardware obligations, the luminosity monitor. And then the freedom to-- And SSC looked like a sure thing, at least as time went on it became more and more certain that we were going to do that. It was very comforting. The science was clear. I mean, we had all of the physics with the Z boson, and then we had the SSC. It was a very great scientific program.

Zierler:

Did you take graduate students with you from Tennessee, or you built the whole thing from scratch at Oregon?

Brau:

There was a couple of students that came with me from Tennessee. One, Kevin Pitts, was the first one. He's now a professor at Illinois. He just recently became Fermilab’s chief research officer, but he's on leave from Illinois. And then we started, I started recruiting other students from the-- I was actually encouraged to build up more students in my group, so I started doing that largely. The agreement that we had when I came was, well, first of all, they offered that there would be a second junior faculty position, but before I came I got a commitment for eventually adding a third. They said, well, once we have-- the department chair, David McDaniels said, "I can't promise you now and I can't commit to a third position now, but I'll support it once we have an opportunity." So the first year I was here, we did a search for a junior faculty member, and Ray Frey joined our group at that time as the second person. Then we had an unfortunate death in our department. Michael Moravcsik, a high energy theorist, passed away. I had good interactions with him when I first came. Unfortunately, he passed away shortly after I came, and the position then was converted over to a third experimentalist. That's how we were able to hire David Strom to come and join our group.

Zierler:

What was the major source of funding for the group at that point? Was it more DOE or more NSF?

Brau:

Well, it was DOE. Of course, it didn't exist when I first came here. There was no funding except for the startup funding. I had to apply. P.K. Williams was the head of the university program at the DOE, and I had some good interactions with him before, largely through my work on uranium. I got to know people at DOE, because that was kind of widely-- there was wide interest in that work on uranium. When I arrived, I applied to DOE for funding, and DOE said, "Well, you've got to also apply to NSF. You have to apply to NSF. We require that." So, I also applied to NSF. In the end, the funding came through from DOE.

Zierler:

What was some of your work for, on an advisory basis, for SLAC at this point?

Brau:

Oh, advisory basis for SLAC? Well, not at that point, I don't think I was getting any requests to be an advisor. I mean, I eventually, I don't remember the years now. I eventually became a member of the SLAC Experimental Program Advisory Committee to review the program, experiments. And then at one point, I was also put on a Scientific Policy Committee, which has a different charge to report to the university. For two years, I was chair of that committee. We reviewed the program. Jonathan Dorfan was the SLAC Director at that time; we reported our findings from the broad SLAC program to the Stanford University administration.

Zierler:

Do you have a clear memory of the first time it dawned on you that the SSC was not going to come to fruition?

Brau:

Yeah. I do. I was in my office in Eugene talking to Mike Marx on the phone. He was at the SSC. And we were deep in some conversation about some technical matter, I don't remember what it was. Something having to do with the GEM (gammas, electrons and muons) experiment. Then Mike said, "We were just told the SSC has been canceled. We might as well just end this conversation." And so we stopped. We just, in the middle of a very technical, very detailed conversation, we just said, "What's the point?" And we stopped. And for the next couple days--

Zierler:

So this is, Jim, so you're saying this was a surprise to you? You did not see the writing on the wall, so to speak?

Brau:

Well, we knew there was challenges going on in Congress for sure. We definitely knew that, and the year before, it had been a struggle to keep support. But we thought, just like the year before, that things had been worked out. That probably it would be, the naysayers-- They had a third of the tunnel already completed. I'd been down in the tunnel looking around. It was kind of fun. But it seemed like it was beyond the point where they would actually pull the plug on it. We thought, despite all the political difficulties, that they would be overcome. Roy Schwitters (SSC Director) was sending out a very confident message that he had had contact with the politicians, and they had it under control. So yeah it came as a pretty big shock. And we knew there were problems, but we didn't think it would actually be terminated. It was a surprise. And I remember that--

Zierler:

Jim, tell me about-- I'm sorry, go ahead.

Brau:

Well just how shocking it was, my office was a typical physicist's office with papers piled everywhere, and in the next few days, I just cleaned it out. I just threw everything away. There was no need to keep-- it was a very good housecleaning opportunity.

Zierler:

[laugh] What dawned on you immediately about all of the physics that was lost with this fateful decision?

Brau:

I was sad. It was really sad. Of course, CERN had already been talking about the LHC. The LHC, since it's in a three-times smaller ring, would be a much more challenging effort and have to achieve a much higher luminosity to get the reach that was needed. So there was a lot more uncertainty there. But over time, people realized that that was the way to go. And I personally put off joining the LHC for quite a few years, looking for other things to do besides putting my effort into that distant, very distant, experiment. I re-devoted myself to the SLD experiment, got involved in the vertex detector upgrade, and then eventually joined LIGO and helped launch the LIGO collaboration. The LIGO Scientific Collaboration.

I was pretty active on LIGO in that for quite a few years before my involvement in the ILC took over my effort. But eventually, our group realized that we needed to join the LHC, because the ILC was not happening. We participated in BaBar for a few years, but that was not what we really wanted to-- we wanted to go to the energy frontier, and without the ILC getting traction and uncertainty about how long it would take, we discussed with DOE, and they encouraged us to make a bid to join one of the experiments at the LHC. So we did.

Zierler:

Now before we get too far away from the early 1990s, I'm curious about your involvement in the GEM collaboration. What was the goal and how did you get involved in the first place?

Brau:

Well, as I mentioned earlier, I was really with Mike Marx and Howard Gordon, and we were... Mike was the spokesman and Howard and I were co-spokesmen of this project that we called EMPACT, which was one of the competitors for an experiment at the SSC. We came in third place, but there was only space for two initial experiments, so we lost out on that competition. The two finalists were L* and SDC (the Solenoidal Detector Collaboration). SDC was where a large fraction of the US community was involved. L* was a Sam Ting led project. And so those two were the two finalists-- SDC was given the go-ahead, but L* was given a provisional continuation. Eventually, the laboratory decided not to support L* to go forward. They asked Barry Barish to try to organize the community around a new concept, starting from scratch and look for the second detector concept. So Barry called us together at Caltech and a bunch of us from the EMPACT group and a bunch of the L*, American L* people, all gathered together at Caltech to hear from Barry about what we should do, and we started then conceiving this design for a new experiment, which became GEM. And that's how it got started.

Zierler:

How did GEM fare relative to its original goals?

Brau:

Well I think it was doing well until things collapsed.

Zierler:

Yeah.

Brau:

It was doing very well.

Zierler:

Meaning that from your perspective, things were on a pretty positive scientific direction? Things would turn out well if they were allowed to?

Brau:

Absolutely, I think so. Absolutely, yeah.

Zierler:

What were some of the technical challenges with the vertex detector upgrade at SLD?

Brau:

We were on a very short timeline: a couple of years from start to actual operation. Getting it all done within a short time was a real difficult thing. You're putting these large, recently developed CCDs on thin beryllium supports, very close to the interaction point. A couple of centimeters from the collisions. And they're mounted in a flimsy way, so that surveying the devices and their shapes and what they're doing in there is a challenge to get the ultimate resolution. You're trying to achieve a resolution that's a few microns precision. And how you've got these CCDs mounted with floppy arrangement.

Frank Taylor played a key role in putting together a surveying operation at MIT that was able to come up with the parameters on every single ladder to tell us-- so every ladder had its own set of coordinates to tell us where all the pixels in that particular ladder were located. Yeah, so we had the CCDs being developed and produced in the UK, they were being sent across the Atlantic. They were mounted and sent to MIT for surveying, and then transported to SLAC, and then assembled into an operating detector, and all of this was going on in a very short timescale for what we had to do. Yale also played a critical role in the US, as well as the Oregon research scientist, Nikolai Sinev, working at SLAC. So, I don't know, it's been a while. It's hard to remember exactly all the difficulties. I think we did a good job on getting it, putting it all together, and it was a great success once installed and operating in SLD. SLAC engineers Knut Skarpaas VIII and Jack Hoeflich played key roles.

Zierler:

I'm curious about your time serving for the HEPAP subpanel, which was in the middle of your time serving for the DOE and the NSF review panel on CMS and ATLAS. How those two responsibilities might have influenced each other on broader questions about, you know, the role of the United States in high energy physics post-SSC.

Brau:

Yeah, the timing of all these? I'm not recalling the exact timing of each of these, but as far as the reviews of the CMS and ATLAS experiments that I was involved in, I thought my role there was to try to help the US programs be as successful as they could possibly be. I was able to bring in a little bit of independent view of some of the things that were going on. Listened to the progress that was being made on the plans and raised a few issues that people hadn't thought about. It was mostly just helping them.

I personally think a lot of the value of these reviews is the effort that the team has to go through before they come to talk to the review panel. The proponents have to put in a significant amount of effort, because they're anticipating that the panel may be a little nasty to them. Whereas the panel, at least in my perspective, is not to be nasty, it's more to be helpful. But their effort in advance of these reviews is very useful and very valuable and a lot of times, until you sit down and just go through everything and prepare for that review, you lose perspective on some of the details.

So that's the way I view these reviews. They're useful but sometimes can go overboard, too. They can be too micro-managing and people need time to do their research. You don’t want to force them to be going to review panels continuously and all the time. There's certainly a trade-off there. But yeah, I always thought my role was to just help them prepare, help them think through things, maybe throw in a few ideas here and there.

For HEPAP, it was a much broader perspective, looking at the broader issues that the high energy program is dealing with. I also served on a P5 panel. Looking at the different opportunities for the US high energy program, hearing advocates and evaluating whether certain things fit into the reasonable budget and so forth. To help, as a committee member, to formulate the strategy for the program going forward. I think those programs are... those panels are important and valuable. But mostly to help the people that are doing the actual work. I’ve also served on panels overseas, such as the physics review committee at DESY, the German laboratory in Hamburg, where I served for several years.

Zierler:

Now for ATLAS and CMS, were you involved at all with the determinations of which groups at the national labs would join which collaboration? I'm thinking for example of the binary choice that the group at Berkeley lab had to face. And where they ultimately chose to join ATLAS.

Brau:

No, I was not involved in that at all.

Zierler:

Now back at Oregon, what were some of the motivations for establishing the Center for High Energy Physics?

Brau:

We had established a healthy experimental high energy physics program, and the way the research is organized on campus is through centers and institutes. Recognition on campus that you're a significant player in the research effort is through these centers and institutes. But the experimental group wasn't in any center or institute. When I came to Oregon the Institute for Theoretical Physics provided a lot of support for me and as I built the group up, they were providing support, but I was never a member of that institute. And after being at Oregon for a few years, and recognizing that it was important for us to get on the roadmap of the university and be recognized as part of the overall research program, I discussed with colleagues in the theoretical institute whether there might be some kind of merger, and we could broaden the role of the theoretical institute. Some of my high energy theory colleagues thought this might be a good way to go, but the theoretical institute was much broader than just particle physics; it included chemists, mathematicians and others. It was really a theory center in a broad sense.

So that didn't fly. After failing to make that work, I decided that I really had to push for the university to establish a center for high energy physics. It would include the particle theorists from the theory institute, but in a secondary role. Their main affiliation would be the Institute of Theoretical Science. But they would also be members of our Center for High Energy Physics. So that was the way it was formulated, and that was the way it was planned along with the theory colleagues. I prepared that proposal and put it into the university, and they evaluated it and eventually gave us the status of being called a Center for High Energy Physics.

Zierler:

And would this allow you to have eminent people coming in as visitors, a place for postdocs to do research for a few years, was that the idea?

Brau:

It didn't provide much new funding. It did provide us with a little more control of funding that was on our return from our grants, which before was all going to the Physics Department or to the Institute of Theoretical Science, in exchange for their support. So, we got a little bit of a budget, but it wasn't new money. It was the indirect from our grants that we then had access to. We then had some support for seminars, and that sort of thing, bringing in visitors. For example, I invited Burt Richter to come and give an inaugural colloquium when we established the Center. It was a colloquium to recognize that we were starting this center. Yeah, so there was a little bit of support.

Zierler:

Now at the same time, you become involved in the LIGO collaboration. What was your first point of contact there? I'm wondering if way back at MIT, if you ever crossed paths with Rai Weiss.

Brau:

Absolutely. So when I was a grad student, I remember we used to have Monday night seminars in our group. The group was called APC (Accelerator Physics Collaboration), led by Irwin Pless. We had a weekly Monday evening seminar. I think like seven o'clock or something like that. Usually it would be someone from outside our group, occasionally someone inside our group, who would give a talk. The faculty would go out for Chinese dinner before and, somehow, I managed to get myself invited to go out to dinner with the faculty before these seminars. I was the only grad student to do that generally. We'd go out to dinner and then come back for a seminar. One I remember very well was when Rai came and gave us a talk on this “crazy” idea he had about using lasers to look for gravitational waves. He had thought through every single cotton-picking detail and it was pretty impressive. And pretty exciting. It really did get me interested in it then, for sure.

Zierler:

Was your laser work, for the Air Force, was that relevant at all?

Brau:

Maybe a little bit. It gave me a little bit of insight into some aspects, I guess. Unconsciously, maybe. [laugh] To some extent. So over the years, when I'd hear about something going on with LIGO, I would perk up and follow it a little bit. I didn't imagine I would ever get involved in it. It wasn't that. It was just more curiosity. And I must say that one of the reasons I got involved eventually is because of Barry Barish, who I built up a relationship with working on GEM. When the SSC collapsed, he became the head of the LIGO effort. I invited him to come and give a colloquium at Oregon on LIGO. He gave a nice colloquium, and then we went out afterwards and I started thinking about it.

Given our situation with what we're doing, and this was before we were actually involved in the LHC, maybe I should think about getting involved in LIGO. Then I discussed this with P.K. Williams at DOE, and said, "This is an NSF project. What would you think about us getting involved in this, kind of between now and when the ILC starts?" [laugh] And he gave a nod to this. He said, "This would make sense. We wouldn't probably give you support for it, but you can probably get some support from the NSF and keep your DOE goal going. But this would be a bridge to the ILC."

Then Barry invited me to come down to Caltech, and I went down there for a couple days and met with the various people and various aspects of it. And I gave a talk-- I think I gave a talk on our vertex detector, while I was there. But that was the start of it. And then I came back and started talking to people at Oregon about this and seeing who might be of interest. Then there was a meeting at LSU to formulate the notion of the LIGO Scientific Collaboration where I went. I think there were just two or three high energy groups there besides the Caltech/MIT and related activity. There was a Michigan group, led by Keith Riles, and me. Perhaps others. We were all asked to put together proposals, to be considered for involvement in the LIGO effort.

So I gave a pitch as to how Oregon might be able to participate going forward. I got interested in environmental monitoring, because that's critical to taking these very, very precise measurements; to understand the environment and the interferences of the environment, both motion and electromagnetic interference in various things. And then ameliorating those interferences. I remember that we had a couple of workshops that I went to trying to figure out how the Oregon group could go off in this direction, and so that's where we went and that's what we've done ever since.

Zierler:

Now in terms of your own expertise as a point of entree to LIGO, was it really detector physics? And the differences might not be that extreme, whether you're talking about ground-based particle experiments or what LIGO was envisioning?

Brau:

I didn't have any specific expertise. It was more general expertise that we had demonstrated we could accomplish things and get things done; take a problem and figure out how to best deal with it. I don't feel like I took any real direct expertise into LIGO. I just had to dig in and show that we could basically take on issues and solve them. Yeah, so after I joined LIGO, Ray Frey also joined me on LIGO. He is my colleague who had been working with me on SLD, and also on the NuTeV experiment at Fermilab. NuTeV was a neutrino experiment at Fermilab that we joined. [laugh] We joined that right after, around the time the SSC went down. Mike Shaevitz convinced me to help with that experiment. So Ray and I participated in that. But anyway, Ray Frey joined the LIGO effort. He joined my initiative and started taking on more and more activities, and eventually he became the leader of our group on the LIGO effort.

We also had an NSF-funded postdoc position, and we hired Robert Schofield into that position. He's been a terrific contributor to this whole issue of the environmental monitoring. Really amazing contributor. His background was in nuclear physics. He had worked with the nuclear physics group that I referred to earlier at U of O. Got his PhD in that group with their on-campus accelerator. He also does biophysics now, by the way. Investigating the structure, the molecular structure of ants and the like by exposing them to radiation and measuring the chemical composition. Which is a fascinating research he's involved in. But anyway, he's really a prominent member in the LIGO Scientific Collaboration.

Zierler:

Now the origins of the ILC, were you in a sense present at the creation? Were you involved in the earliest discussions, that this was something that was worth pursuing?

Brau:

Well, so I remember hearing from Burt. So of course, Maury Tigner is credited with being the very first person to write something up and publish it. Maury Tigner at Cornell. And I remember hearing from Burt when I was still at SLAC as a postdoc that this was, well, I guess it was the SLC first, but the idea was to take the linac and collide electrons and positrons with one linac, as a first step towards a future machine that would actually be two linacs pointed at each other. That was the start of the SLC.

But the natural thing was then to envision the next step beyond the SLC, which was the NLC, the Next Linear Collider. At SLAC, a few in the SLC started thinking about another project beyond SLC, the Next Linear Collider. Simultaneously with this, the DESY people were also thinking about a similar collider they called TESLA (TeV Energy Superconducting Linear Accelerator). They wanted to site it in Hamburg on and near the DESY site. The Japanese had something called JLC (Japanese Linear Collider). The technology of the JLC and the NLC were very similar in that they used warm cavity technology: X-Band acceleration technology. Whereas TESLA was built on the superconducting RF cavities, which eventually became the concept for the ILC.

You had these three efforts in the world, all developing their notions and pushing for their particular notions. But at some point, ICFA took charge of this and said, we really must come together. If we're going to realize this, we need to come together. They created a committee (International Technology Recommendation Panel) chaired by Barry Barish. That committee then reviewed over a period of time the two concepts, the warm X-Band technology and the superconducting RF technology. Based on the pros and cons of each and the risks and rewards, came out with a recommendation that the world should rally around the cold technology. I remember I was in Beijing at the conference, the International Conference on High Energy Physics in 2004, where ICFA was meeting to hear the report from Barry about what the recommendation was. Hitoshi Yamamoto from Tohoku University and I were co-chairs of a worldwide study of physicists who wanted to work at a linear collider. We were leading that effort.

It was the physics community as opposed to the accelerator community. And we were invited to come and give a report to ICFA as a break from their meeting with Barry. Barry wasn't there. Barry was calling in. Jonathan Dorfan (SLAC Director) was the chair of ICFA at the time. He was, of course, a big advocate for the X-Band technology and was going to give a report to the larger gathering of the conference later that week. So Hitoshi and I went to the ICFA meeting to deliver our report on the physics and detectors. It was on the IHEP campus in a small room whereas the conference was over in a major hotel. We had to go over there. Went into this small meeting room, and I was really trying to read people's faces and trying to guess what was going on. I had a few words with Jonathan Dorfan, and he... what I recall him saying is, "Don't judge from the look on my face what the decision is." And I had no idea which way it would go. I had no idea what he meant. I think what he meant, in after thought, was that he looked okay, but inside he didn't feel okay. I think that's what he meant. But he didn't say it that way.

And so it was a mystery to me. Then he announced later at the conference the recommendation, and that the decision was to move forward with the International Linear Collider using superconducting RF technology. Those of us working in the worldwide study of physics and detectors were not so directly impacted because we wanted to do the physics no matter how the machine was built. But the laboratories who put so much into their efforts on the losing technology, like SLAC for example, which I was more familiar with, really had to reorient themselves significantly.

Zierler:

I'm curious the extent to which discussions on both the ILC and the NLC centered around an understanding of the limitations of the LHC, and to what extent were you after problems that were simply not relevant to what was happening at CERN?

Brau:

Well... it was sort of--

Zierler:

In other words, in order to carve out a research agenda, don't you first need to define what's currently in the works for CERN, and what would never be feasible given the infrastructural limitations of the LHC?

Brau:

Well the thing is that the ILC, and the NLC before it, is so complementary to the proton collider, that I don’t think of tradeoffs, more so the complementarity. You access similar physics, but you have limitations on the energy reach. The original concept of the NLC was to go to 1.5 TeV total center mass energy ultimately. And you can think about that 1.5 TeV compared to what we're now talking about trying to get a 250 GeV collider established with the ILC. We've come down a long way. But that is because we didn't know the mass of the Higgs boson. We didn't know that. Now we know that 250 GeV does a fantastic job with the Higgs boson because it's only 125 GeV of mass. If it turned out that it had been a TeV of mass or 800 GeV of mass, it would have been a completely different ballgame.

At the time, we were pushing the limit of the energy to a pretty high level because of that uncertainty. But the confidence was that it's complementary to whatever happens with the proton machines, because of the simplicity of the interactions, the relative fraction of the interactions that are of the electroweak nature compared to the hadron collider, which is dominated by lots of events that you just cannot deal with. You have to build sophisticated trigger systems to throw most of the data away.

The ILC is much simpler; the way you access the Higgs bosons at the ILC is through the so-called Higgsstrahlung process and you don’t need a trigger – you keep all the events. We've always understood they were very complementary. Because you're interacting fundamental particles as opposed to the protons, which are so complex. You have much simpler interactions and a much better handle on what's going on in the interactions. And the detector technologies are really different, a lot different in many ways. We also recognized from the detector perspective that we can develop concepts for detectors that are much different from what the LHC has to do with its environment. So for example, we have envisioned that the material that we have to embed inside a detector for cooling the electronics is negligible. Whereas it's a big factor in the LHC experiments. This affects the precision of the measurements.

Zierler:

When did your group formally join ATLAS?

Brau:

We joined in 2005.

Zierler:

So this was still early enough where discussions about the discovery of the Higgs are far off but they're becoming more palpable, is that a fair way to describe the scene at ATLAS at that point?

Brau:

Well, I don't know what you mean by that. We didn't have direct knowledge of the Higgs mass-- I mean, from our measurements with SLD, we were pretty confident that the Higgs was light. That was an indication which was confirmed. And LEP also favored, not as light as SLD, but it favored a light Higgs boson from the electroweak precision measurements. So SLD and LEP were pushing, from a theoretical perspective, towards the prospects of a lighter Higgs boson. But experimentally at that point, I don't think we really had much to go with from direct results. It was later that we started getting collisions and eventually in 2012 had the actual observation.

Zierler:

How much time were you spending at CERN yourself?

Brau:

I wasn't present so much. I mean I went there occasionally. It was postdocs and other faculty members that would be present there more. We now have a little over half a dozen of our group members in residence there. Sometimes it blooms up to ten or so. But personally, I haven't gone there as much as the others. We communicate effectively through the internet with video conferencing and email.

Zierler:

I was asking about the years prior to the discovery of the Higgs, because I wanted to get a sense of from your vantage point, was this rapid or it was gradual? In other words, was there increasing confidence over a number of years that the Higgs was where it was? Or was your sense that that really happened quickly in a compressed amount of time?

Brau:

There were hints of a number of things before it was clear that it was at 125 GeV. So from my perspective, it was a pretty rapid announcement that the data was there at the 125 GeV. I remember evidences for other-- now, the thing is, the early evidence, and I've forgotten the years now, but the early evidence of this little fluctuation was not giving me a lot of confidence that that was a real thing. Because you get these effects and they go away. So I thought until we got the data there in the final analysis, it was really unsure where it would be. That was my perspective.

Zierler:

Were you involved with LIGO consistently, or would you come in and out of the collaboration?

Brau:

Early on, I was very active in LIGO. For the first several years, I was on the executive board. I would participate in all the collaboration meetings and helped establish our role. Mostly at Hanford, we were getting involved there. Taking on activities. But then, my role faded over time, and I was distracted by my role in the ILC. Since coming to Oregon, I've assumed the responsibility for a strong research program on three fronts. That involved an ongoing high energy physics experiment, which is now LHC and has been for a long time. A future high energy physics effort, which is ILC. And the LIGO activity is in addition. It's just kind of the cream on the whole project.

So, for our research group, my vision had been to have a broad enough scientific spectrum of activities that we could have a number of faculty; we have seven faculty now involved in all of this starting from that first guy that got hired. We have a viable program in the trade-offs and the different things, keeping us involved in exciting new things going on. But that means that my particular responsibility is largely aimed at the long-term future, because that's kind of where I have to go in order to keep that particular aspect going. It's not paying off to other people as much. [laugh] They have other needs.

So, the ILC has been a distraction for me from all of these other things for all of this time. And I don't regret it at all. I mean, because I think it's really important that we get that thing built for the future of science. I've been involved in each these other projects more intensely in the beginning, and then other people would come in and take on a more active role, and I would free it up to really keep pushing the ILC. Which has been my main thrust.

Zierler:

Jim, given your involvement in both and their chronological proximity to each other, I wonder if you might compare and contrast both the data analysis and the politics surrounding the announcement of both the Higgs and the detection of the gravitational wave?

Brau:

Mm, that's interesting. Well, the politics is interesting because, on the LIGO side, Rai Weiss was always advising people that we had to be really cautious about announcing the discovery of gravitational waves, because they had been “discovered” before and it turned out to be wrong. He was very cautious about the discovery. We anticipated that it would take a few events before we could make a public announcement. But in fact, that first event (GW150914) was so strong and so convincing and so overwhelming. I guess there was a little bit of worry on whether somebody had actually planted data somehow, but it was so strong that the fear of making this announcement and it turned out to be incorrect was no longer the case. So on the basis of one event, the announcement could be made. Now in the case of ATLAS, you're looking at a large number of events that you have to build up in order to establish the statistical significance over a large background. In that sense, there is quite a difference there, in just the way it works. To get the 5-sigma discovery thing requires building up that statistical significance. They're really kind of apples and oranges almost in terms of how that operates.

Zierler:

I'll ask an even more technical question comparing and contrasting, and that would be the role of redundancy in both, where you have for the LHC, you have CMS and ATLAS, and for LIGO you have the sites in Washington and Louisiana.

Brau:

Yeah. So absolutely, those roles are important, and yeah, I mean, critical. Critical.

Zierler:

When did you become most optimistic that the ILC ultimately would become a reality?

Brau:

[laugh]

Zierler:

Or has that ever been the case?

Brau:

I don't think I can be totally optimistic that it will ever become a reality. I think it's--

Zierler:

What kind of numbers are we talking about? If we want to look at the SSC as a warning, right? Where you know initial numbers were like 3 billion, then it got up to 10 billion, 12 billion. What are some of the warnings or lessons learned in terms of coming up with accurate budgets at the outset and sticking to them?

Brau:

Well, it's very important that what the proposal envisions as being the cost of the facility is accurate. The Global Design Effort, led by Barry Barish, the team that was set up shortly after the decision to go to the cold technology and build the ILC, the Global Design Effort put in a very significant effort over many years, with good, solid funding in the US from DOE and also funding overseas. DOE was devoting about $35 million a year to the R&D program in the US to develop the technology, but also understand what was involved in building this thing and coming up with an accurate, reliable cost estimate. And that was complemented by activities in Japan and Europe and elsewhere to some extent.

There was a significant, intense effort to understand that cost, and I have a lot of confidence that it's not the kind of preliminary cost that was being floated around in the SSC days. There a very immature estimate was publicized-- but that number would stick around and then people would start to look at the details and it would end up being a bit more here and a bit more there. I think we have a better understanding, and the cost that was developed for the TDR, Technical Design Report, for the ILC now has been updated and adopted by the Japanese and their team and collaborators for the new approach, which is to optimize at a lower energy initial stage. They’ve reviewed all of the details. And it stands up pretty well after those reviews with more mature understanding. I think it's absolutely important that those cost estimates be firm and reliable, and I'm confident that we have those in hand, that we know those costs well.

Zierler:

Jim, what are you confident about with regard to the ILC if it comes to fruition, where new physics will only be able to be detected there and not at any of the current facilities that we have?

Brau:

Well, so one of the things that I'm particularly interested in is the Higgs boson decaying to invisible objects. In the Standard Model, the way the Higgs can decay invisibly is through a virtual process of two Z bosons that result in neutrinos in the final state. At the ILC, you can detect this process as the e+/e- creates a Higgs boson along with a Z boson in the final state, the so-called Higgsstrahlung process. You detect the Z boson and from the reconstruction of the Z boson you detect a recoiling mass that is equivalent to the Higgs boson. And so before you look to see what's there along with the Z boson, with some backgrounds, but a manageable, understandable background, you know that you have a Higgs boson on the other side of the event. And so with the ILC in the first stage, we can measure this to better than a few tenths of a percent in the branching ratio of the Higgs boson. The Standard Model is just below that level.

So, we can get very close to this neutrino final state of the Higgs boson and see that we're down there. But if there are any other new particles that the Higgs boson decays to which are invisible, we may reach those first. We'll find that this rate is greater than the Standard Model. And right now, the LHC measurements are about two orders of magnitude larger. Their limits are about two orders of magnitude larger than the Standard Model, and they hope to push this down significantly, but there's no way they can ever reach the Standard Model or something that might be a factor a few times larger than Standard Model.

So that's one great thing that we can definitely do. But more generally, we can measure all of the other decay modes with great precision. How often does the Higgs decay to charm, for example? How often does the Higgs decay to bottom quarks and well, that's pretty well measured by the LHC, but how often does it decay to tau leptons? It's one thing to make measurements. It's another thing to make them very precisely. And when you make them very precisely, then you can say, does the Standard Model agree with these precise measurements? We know we can do this very, very well at the ILC and if there's new physics, we'll start to see systematic deviations in these branching ratios. Some going up, some going down depending upon how the new physics interacts with the Higgs boson. And that would be extremely exciting. We know we can make those measurements. So we'll either find that the Standard Model is really, really solid and confirmed, which isn't expected, or we'll have some significant evidence of not only the fact that there is beyond the Standard Model physics, but also the nature of it based on how these systematic deviations show up in the different channels of the Higgs decays.

Zierler:

Jim, the way that you talk about it, it's noteworthy because theorists tend to talk about physics beyond the Standard Model as a foregone conclusion, but perhaps as a dyed in the wool experimentalist you seem to be a little bit more cautious about that.

Brau:

I'm not-- I personally know with 99.9% confidence that there is physics beyond the Standard Model. But I don't know where it is. It may be way outside of our range. It's not likely to be way outside of our range, but it might be. We don't--

Zierler:

Even with the ILC, you mean?

Brau:

Yes. It might be outside of the range of the ILC. So that's why I say that if the ILC confirms the Standard Model, then that tells us that this thing is way, way out there. Or somehow doesn't interact with the Higgs boson. That's another possibility. I also believe that there is new physics, I just don't know where it is. I believe there's a good chance that it's in reach of the ILC. There's a good chance, and the chance is significant enough that it's worth going after it there, and as I say, the worst that would happen is we'd put extremely new limits on where that new physics is.

Zierler:

Jim, what about some of the potentials for advances in cosmology as a result of the ILC? For example, I'm thinking about the dark matter experiments at the LHC. In what ways might the energies envisioned at the ILC be useful for some of the major mysteries that remain in cosmology?

Brau:

Well, if you're talking about dark matter, I mean that's what I was referring to also when I was talking about invisible Higgs decays. Because there could be dark matter particles that couple to the Higgs boson. Which are very hard to see in other experiments, but when you've got a Higgs decaying to them, say, 1% of the time or thereabouts, they would stand out in this experiment. But there are, beyond that, there are other ways that the dark matter particles might be observed in ILC events. And because of the nature of the events, where the backgrounds are so low and the understanding of the events is so good, and we can record every single event onto our disks and study them for as long as we want. There's much better chance of finding some of this going on by looking through many different processes, that it might interact with. But the starting point would be the Higgs couplings.

Zierler:

Jim, perhaps this is as much a philosophical as it is a scientific question, but in contrasting your certainty of there being physics beyond the Standard Model, but not being so certain that that's going to be confirmed through the ILC, well, if not the ILC then what? Is it just energies that are currently not feasible technically or administratively or budgets, or is it something else more fundamental about the limits of experimentation and observation?

Brau:

Well, there are many different approaches to this. We have underground laboratories looking for interactions of dark matter particles. We have things like the G-2 experiment that's looking for evidence. As we discussed earlier, we need the theoretical confirmation of and a consensus on what is correct theoretical analysis to understand that. Then there are the astrophysical observations of things that are going on. There are a number of different avenues for this, and it's hard for me right here to say, “Well, this is what we should do.” I think we should do as many searches as we can possibly afford to do and do well. We don't want to just throw money in the wind. But as many different directions as we can conceive of and have the manpower, person power, and resources to do well, we should do. Because it is pretty clear that there is physics beyond the Standard Model. That there is something going on in these cosmological observations and it would be just so revolutionary to figure out what it is.

Zierler:

Have you retained an affiliation or a collaboration with advanced LIGO or VIRGO?

Brau:

I participate in our LIGO group at the University of Oregon. We have group activities that I'm involved in here. And then I follow what goes on through communications from the collaboration and the papers and so forth.

Zierler:

And of course, the public misperception is after the Nobel Prize announcement that the detection of the gravitational wave meant mission accomplished and you can wrap up. In what ways is advanced LIGO and VIRGO even more exciting potentially for what it can do?

Brau:

Well, there's just a population of events that are being built up of coalescing objects, mostly black holes coalescing but also neutron stars involved in this as well. The statistics are rapidly increasing as the sensitivity of the interferometers improves. Building up the population is allowing an understanding of the systematics of the populations of black holes in the known universe: what their origin is, what their evolution is, and also there are some interesting things going on with the neutron stars. So no, it was originally envisioned to be a discovery of gravitational waves, but we always knew that it would be a new astronomy that was formed by this capability, establishing this capability.

Now we have TAMA in Japan coming on and soon collaborating and coordinating with VIRGO and the LIGO. And also in India, there's a facility being developed, out of the LIGO collaboration. So we're just-- it's like the radio astronomy, when it developed, including out of the radar capabilities developed during WWII. Radio astronomy burgeoned out, and we learned a lot. That's how we discovered pulsars and all kinds of exciting aspects of galaxies and the universe. It just went way beyond the first observations. We're just now at the frontend of a whole new astronomy built out of detecting events in the universe from these gravitational waves. Gravitational radiation as opposed to electromagnetic radiation.

Zierler:

Jim, one aspect of your career we haven't touched on yet is your role as a teacher to undergraduates and a mentor to graduate students. So first on the undergraduate side, what have been some of your favorite courses to teach over the years?

Brau:

Well, I have often taught astronomy to non-science majors. My teaching assignment has been pretty standard. One year I teach graduate-level particle physics to the graduate students, and in the alternate years I teach undergraduate astronomy to the non-science majors. This teaching of astronomy to the non-science majors, which are large lectures, ties in nicely with my interest in popularizing physics. I've given public lectures over the last several years on many different topics. I had a sequence going at the library where every several months I would choose a new topic to talk about, some I’m directly involved in (high energy colliders or LIGO), as well as others. Like neutrinos or dark matter, whatever. I would just go into the library and tell people about what's going on. Generally these people are excited to hear from somebody that's even loosely connected with this science. But I really enjoyed teaching the undergrads, non-science undergrads. We have a large number of students who enroll in astronomy because it's one of the ways that is popular among them for their science requirement. And there are just so many exciting things to talk about in any aspect of astronomy.

Zierler:

Jim, with your graduate students, I wonder if you might reflect on any distinctions you might see between when you were a graduate student in the 1970s where in particle physics, particle theory, particle experimentation, in many ways, the world felt wide-open. That things so fundamental and foundational were being discovered every month, every year. Is your sense that that is still true today? And if not, what kind of caution might you insert into the kinds of things your graduate students work on?

Brau:

Oh, let's see. So I don't know if it's so different in terms of the frequency of discovery. Yeah, maybe it's a bit different, but not so different, because there are many different experiments going on. Lots of different experiments in particle physics or areas related to particle physics. Personally, I'm excited. For example we talked about the G-2 measurement. It's exciting what they're doing in trying to unravel and figure out what it means. It's an anomaly that we need to understand. And certainly if we started discovering new particles, that would be even more exciting. We're not expecting to do that too frequently, but when I think back it was a little more frequent maybe. But it wasn't every month there was some major new discovery. It was every other year or something, you'd hear about a major discovery in particle physics or maybe every few years. It wasn't so different.

So personally, what I advise, this may not be exactly what you're asking, but what I advise students to do is to figure out what they're really interested in, and to follow their passions in that direction. Don't worry about whether or not that's going to get you the next position or whatever, where you're going to be in ten years. Worry about today, what you're really interested in, and just work as hard as you can on making that a success, and then everything will work out in the end. I'm pretty confident following that philosophy. That's a philosophy I have followed in my career, when I was told not to go back to graduate school because I was just going to waste my time. I wanted to do it because I was passionate about the science that I could be a participant in. A small participant in some exciting things. And I advised my students to do the same.

Zierler:

Jim, for my last question I'll try to tie it all together. Between your interests as a communicator for science, in all of your advisory work, in and adjacent to Washington, DC and with all of your international collaborations, looking to the future for foundational discovery to continue obviously is going to require an enormous commitment of public funds. So in all of the ways that you think about the science, in all of the ways that you communicate the science, what have you found as the most efficacious means of convincing the right people, in policy, in positions of budgetary authority, that this is the kind of science that's important to fund?

Brau:

So you say influencing the right people. I probably don't have a lot of opportunity to influence the right people. I find first of all that an awful lot of public appreciates fundamental science. Appreciates knowledge and learning new things, and really responds to the discoveries that are being made. And they know that these don't happen without a lot of effort and a lot of support. I feel an obligation, but also a pleasure, to communicate with the public about these research developments that they are supporting through taxes. Returning to the side of the politics, unfortunately politicians, many of them, take a short-term view of things, and don't often-- I shouldn't say everyone, but often there's not a long-term vision of what the implications are for various things. Investing in fundamental science has long-term payoffs in addition to the reason we're doing the fundamental science. They're the benefits that accrue to society as a result of doing those things.

We can list many examples of this, but just the training that young people get as a result of participating in these technical efforts and the skills and capabilities that they then can take with them to pursue other challenges in industry or even beyond that, is extremely valuable. By exciting young people in the science, even at a very early age, because the science exists, because there is support for it, and because there is really new and exciting research going on, they get involved. They think “gee this is great,” they grow, they develop, and they become achievers over time. Ultimately, we don't know where they're going to go, but they are going to contribute in the long term. I think that's just one aspect, but that's a very important aspect, and we have to keep the long-term vision in mind when we ask, "What's the value of doing the fundamental science?"

Zierler:

Well Jim it's been great talking with you. I'm so glad we were able to do this. I really appreciate it.

Brau:

Well thank you.