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Interview of Leon Lederman by Rik Nebeker on 1990 May 7,
Niels Bohr Library & Archives, American Institute of Physics,
College Park, MD USA,
For multiple citations, "AIP" is the preferred abbreviation for the location.
In this interview, Leon Lederman discusses his neutrino research. Topics discussed include: Brookhaven National Laboratory; European Organization for Nuclear Research (CERN); Fermilab; Taiji Yamanouchi; Chuck Brown; John Yoh; Bob McCarthy; Nevis Laboratories; Georges Charpak; Saclay Nuclear Research Centre; J. Steinberger.
Leon Lederman at his office at Fermilab on the 7th of May 1990. The interviewer is Rik Nebeker. I wanted to ask you about the submission of that proposal in 1970. You just mentioned this grew out of an earlier experiment at Brookhaven. Can you tell me how this proposal came to be?
The sequence of events goes something like this. In 1962 we did the neutrino experiments at Brookhaven. The patient is relevant. Then of course with the success of 50 events we then redesigned the experiment to shoot for a thousand in the second phase of that neutrino physics. A new area was designed by this time, the whole lab was quite interested in pursuing this. We'll extract the beam. Whereas in the original experiment we ran at a large angle to the beam, now we were at zero degrees, the intensities would go up. We built a new massive detector instead of ten times it was a hundred times, and a new shielding wall was erected. In the shielding wall we buried a lot of holes, because we knew one of the technical problems would be to know how many neutrinos we had. So we decided to monitor that by looking for the accompanied muons that would have a decay in flight, pions and kaons decaying in flight and you've got a neutrino and a muon. Sample the muons and from the muons we would know how many neutrinos there were. That was a flux measure. I could dig up the years, but this must have now been 1964, 1965. We ran that experiment. I think about half way through the experiment, by this time, we'd had our hundreds of events, maybe a thousand or so. Probably a thousand. We realized that we had enough events. We then said we could convert this experiment. We were bored with the events. There were too many events by that time that we couldn't classify. We had events we could classify, but there are events, we called zoo events, and a number of unclassifiable events were so large, that it didn't seem to be (???) for us. We weren't going to get more data. Even if we had been cleverer, we would have concentrated on the neutral current phase of that. Any way, we weren't clever, we said, we could convert this. Now, in the first experiment and the second experiment, one of the mode [?] of motivations was to find the [???] boson w particle. We thought that could be done, because neutrinos would make w's. Then we said, "Gee, protons make w's not much better, largely because the neutrino is a tertiary beam." So the average on the beam is 1 (one) GeV. Whereas the protons would have the full energy of the machine, whatever that was 27 or 28 GeV. You'd get much more w's if we could use protons. So we converted the experiment to one in which instead of having the protons hit a target and a very long flight path for the pions to decay, we transported the protons right into the shield, this massive shield. Then we used these probes.
That was an iron shield?
It was a thick iron shield, whatever battle ship had been cut up for this shield. These holes in the walls were used to probe for muons which would be now the decay products of the w. Turned off the pi's and k's because they have no decay path. And so, any muons we see, would be the residue of those pions which did decay with their path life, much, much, much reduced and w's which we gave a particular large transverse. We did a search for w's and it was negative. Then moved the limit from something like 2 GeV at mass to 5 GeV at mass. At that time, no one dreamed it might be heavy as 80. But that it is a very sensitive experiment. We published that experiment. Somebody wrote a thesis on it and we got interesting theoretical criticism which was published in Nuovo Cimento in 1965 by Nagushi and then some [???] [???]. Most of these guys had seen muons characteristic of the w but they couldn't prove it was a w, it might be a virtual photon of pi mass, which would give rise to two muons and they would be seen as one of the muons. So they criticized the sensitivity of the experiment. To me it was a total revelation. I said, "My god, will two photons make massive objects. That's terrific. Why don't we use them!" So that led to the next proposal at Brookhaven. That was submitted in 1967 to look at pairs of muons at virtual high mass states of photons. Because high mass is small distance. We would be studying small distance behavior. At that time, I think I try to remember the sequence of events. We thought this was a superior way also to look for resonant states, vector mesons, because they have the same quantum numbers as the photon. If you use the highest energy you have available, protons bashing into a target, making everything, we didn't care. In fact we invented what later became known as the inclusive reaction, because we didn't care. All we were looking for was this virtual photon. We could see it because it decays into muon pairs, and muons penetrate a lot of material. Everything else is absorbed. We're looking only at that aspect of the reaction.
This was a double-armed spectrometer?
Yes. It was a two-armed spectrometer. It was a very crude thing to look for these pairs, we designed an experiment of great economy, the argument being that we were going to hit a dense target within a varied density and extrapolate to infinite density. Therefore get rid of all the pions and muons by extrapolation. Then there would be 10 feet steel in the path of the muons, so we get rid of all the hadrons. That will produce a lot of multiple scatterings. There's no sense having high resolution after that. So, we made some planes of liquid simulation counters, separated by material. We were measuring the energy in muons in range bins, thick range bins and angle bins. So, it's a very simple experiment, ingenious in the fact that all the crudities matched so that later when we would panic that we would love to get more resolutions and there's nowhere you could get it, you'd have to change the whole experiment. This was the result. We said, "Well, when we've found this famous shelter at Brookhaven and a big yield of muon pairs that went out to the kinematic limit and beyond the masses, using the Fermi motion, I think we went down 8 orders of magnitude from 1 GeV to 6 or 7 GeV. This very suggestive shoulder [shelter]. We said, "Okay, we have to rebuild the experiment we might as well do it at a high energy machine." At that time there were two, the ISR was going to come on in 1971 and so was Fermilab. So, we split up into various people and I think I got two interested in helping me do the ISR experiment at CERN. This was the core group that put in the proposal.
How many of these people were part of that Brookhaven experiment?
None. That's the trouble. When you're at a University, people vanish as soon as they finish an experiment. The students on that experiment was Bernie Pope, who went off. In fact he went to CERN as a postdoc. Zabateni was a European visitor. Went back to Europe. Kim Christiansen got a job and he was a postdoc, or assistant professor at Columbia. He got a job at NYU I think. Zabateni, Christiansen, Pope, George Hicks, was another student who went off and got a job someplace. There was a total of about seven people. Zabateni, Christiansen, Pope, Hicks; maybe another name will come.
How did you assemble this group?
It's done by magic. Appel was a postdoc at Columbia. Lee was assistant professor.
Had you worked with him before?
I think this was our first collaboration. Then we recruited Yamanouchi who I'd worked with on muon scattering, when he was at Rochester. These other guys we picked up. Sculli was a student of mine from NEVIS experiment. The Old Boy Network/Old Girl Network, things like that.
What about Tannenbaum?
Tannenbaum was another student of mine from an earlier experiment. That's okay.
A number of these people didn't continue.
That's right. I've forgotten this, but this was a very early stage of that. Gradually there was a shift of characters and some came and some. Appel I think stayed there. Lee a little bit later went off to do some of his own stuff. We added Chuck Brown, who came from Fermilab. [???] from Fermilab. We picked up some postdocs and some students that were in on this, graduate students.
These others, Tannenbaum?
None of these guys were graduate students. I don't know what date we submitted this. June 1970. That's pretty late. By that time a graduate student would be ok, usually you don't get graduate students, until you can smell the data.
I'm just wondering why about half of these names don't appear afterwards.
It's a standard thing. In these tiny group experiments, I thought there was a lot of names. We need so many people.
It wasn't as if there was a falling out.
No, It was a natural thing. I don't know how often that still happens. I guess it's a question of the phase of the proposal. We put in a proposal and then there's negotiations and a year or two years goes by, then finally you sign an agreement. By the time you sign the agreement, then you've made a pretty strong commitment.
It was approved in December of 1970, the proposal, a later version of it. This is a very large document, around 80 pages or something. Do you remember who wrote that up?
I believe it was. I think Appel was the guy who worked closely with me at that time. We didn't have any of the graduate students yet. I remember there was Snyder.
Here's the list.
David Hom, right. Ken Gray is a technician, Gaines, these are all Columbia graduate students. And a European visitor, Maurice Bourquin, showed up. We grabbed on to him. Jean Paul was another guy sent to me by Jean Marc Gallard who's a good guy who loved spending a year in the United States. A lot of these guys were my students. There are some guys here I don't recognize. Tews I don't recognize at all. Snyder was a Columbia graduate student. Hans Paar was a Columbia graduate student. David Hom, Irving Gaines, all students. John Yoh was a postdoc. In fact he was also involved in the...he was a student of Alvin Tol. I worked next of transistors at Brookhaven for some years. So I knew John pretty well.
Was it the case that you were out recruiting people in these years just to have enough people?
Yes. When you wanted an experiment, you go find them. Daniel Peterson is a name I don't recognize. William Flavel I don't recognize. These were all on the proposal.
That I doubt.
I see technician. You have technicians on here. I wouldn't... the ones I don't recognize are technicians. Some of the names never stuck. That's right Bruce Brown and Yamanouchi joined the experiment. We should look at David Saxon. I see you have scribbled that here, he was from England and joined us for a year, a year and a half. We should look at the publications, and I have those. We published a lot of stuff. Very much it grew out of that Brookhaven experiment. Looking back, if we stayed at Brookhaven we probably would have found, gotten the answer very quickly. We were interested not only in pursuing the physics, but also in going to a higher energy. There were these two opportunities. Both at CERN, and both on a CERN experiment was a collider experiment. I very much wanted to get experience on how you do those experiments, in a pioneering machine, proton head on collisions, which would have given us a big energy. For many years I gave this talk on how I missed the Jaysi in three different experiments.
I read about that. So it was a matter mainly of higher energy to be available?
That's right. So that it would be a bonus not only would you pursue the same physics, but presumably with a greater incisiveness and bigger mass spread. I was very charmed with the technique. I remember once comparing it, much to the favor of this approach to the E+ E- guys, who were doing in some sense the opposite way. We were producing lepton pairs in a final state and they were using them in the initial state. Essentially to pursue the same physics. I said, "Those guys are nuts to do it that way, because you're stuck with the incoming energy." At that time, I wouldn't dream that they could scan an energy. I didn't know that machines could do that. But here, whatever energy it is, comes out. They all come out by themselves. So it sounded good, made a plausible argument and got the PhDs interested.
Do you remember any difficulty in getting this approved?
The first one we had some difficulty in getting approved. The Brookhaven experiment I remember I had to fly back from some meeting in Colorado because they were saying, well, the director which was Maurice Goldhaber said, "Maybe we should wait a year. What's the hurry, we're busy and so on." I would go back and jump up and down and say we have a team, we have students and all that, and this is something that we should do right away. Anyway, we got it more or less on schedule. We ran in 1968, 1969. We had these millions and millions of lepton pairs. It was a nice experiment, because we were taking the data in the background of a thousand times as many randoms. It was a very powerful way of subtracting enormous number of randoms subtracting two very large numbers in order to get a significant residue and satisfying yourself at the residue. I must say, indirect enough to make some of us very nervous about how to interpret that problem. The group had a great fight about what to say about that. Zabateni being the one saying, "It's a resonance, we should publish a resonance" and so he was convinced. Christiansen was the conservative, said, "You can't prove it's a resonance." I was sort of persuaded by Christiansen who suggested that there was no way to prove it was a resonance, all we could do was say, "It's a bug, give it a cross section." and do whatever. It wasn't so wrong...
And it did attract attention?
Yes. And so did the continuum. The continuum produced hundreds of theoretical papers. I counted well over a hundred theoretical papers that came out. One of which was [???] he started a cottage industry. In a way it was very complimentary to the people at elastic scattering. The [???] turned out to be theoretically more resistant to confidence [???] that the first vote of terms was significant. People in elastic scattering were essentially getting the same information on the existence of quark like objects. Quark and [???] is a quark anti- quark annihilation.
Were you bothered by the necessary delay of doing this at Fermilab? The beam didn't come up.
Yes. All of us were jumping up and down with disgust and frustration. On the other hand, this wasn't the first new accelerator that had some…
I assume you were in hurry to investigate it.
We are always in a hurry. It wasn't the machine that slowed us down as much as a red herring. The red herring was first uncovered by Dave Croning who was doing a single arm... See, the proposal was for a two armed spectrometer.
In a later phase, I think it's called phase III of 70.
Perhaps, I don't remember that. We said we would pause and do a single arm. Croning was doing a single arm also at a much smaller acceptance, but it takes a higher beam. So, they were sort of comparable experiments. He discovered there was a yield of leptons at the single arm which was equal to the [???] the pions.
Where was he doing his work?
Here. And so there was this ratio term minus fourth that seemed to be independent of transverse momentum which was the relevant parameter if you have only one particle you're looking at. Primary energy seemed to be a constant of nature [???], ten minus four. Other people at CERN found this same ratio. I would say we started in 1973 and we spent that whole year and much of the next year on that dumb number which turned out to be an accident. It was later as we were talking there was a cocktail, there was a little bit of [ ???] in there, the was the row, row 5 omega was contributing, the J/Psi was contributing to the charm. It all added up to ten to minus four for no good reasons, but it certainly distracted us, and delayed our installation of double arm. And suddenly there was the November revolution.
And you moved more quickly to the double arm. What about the support that you got from the lab here in the first years. I understand the so called P central pit was built for E70.
That's right. We had a lot of interaction with the builders, as to shape and size and so on. We didn't bargain on the frogs and the water leaks, and the roof leaking and all that stuff. Looking back, the charm of the pioneer spirit of doing experiments at the early, early Fermilab. I think we got pretty good support. Wilson tended to want to be convinced about any expense, if we wanted a crane he was sort of pathologically against the crane. Once we explained why we needed the crane, he would let us have our crane.
So you had good relations with him?
So 70 is taking data in 1973 and 1974 and then the November revolution and it was a direct results of that, and you decided, now we've got to go to the double arm.
Enough of this fooling around with the single arm.
Also at that time, the experiment was given a new number.
288, that's right.
What was the reason for that?
I think that the administration decided that it was different enough from the previous experiment to deserve a new number. There's always a little bit of [???], the higher the numbers go, the more activity you can show DOE, with all these experiment's we're doing some of that.
What about this particle search, 187 that [???] for the first years?
Yes, there was the...there was Peter Lyman. He's an original Brookhaven crowd. He was a postdoc from Wisconsin, who came and joined us at Brookhaven. But it was the same crowd. What were we doing? Boy, I don't remember.
Was this the time of flight?
That's what I was wondering about. If it was the time of flight, we were looking for stable particles. Biddle's name should have been on it. Biddle was a graduate student on my CERN experiment. He was writing up that experiment but he was back at NEVIS and he helped us. He was bored with writing up, so he took, this whole thing was a run in a few weeks, he just helped us do that experiment. I don't see his name here.
These lists are often faulty.
That might have been time of flight technique, looking for some of the massive stable particles.
How did it go in converting to the double armed?
There was a whole sequence of things. The first question was do you want to look for muons or electrons? We had developed in a single arm case a very powerful technique for suppressing pions and picking out electrons. Probably the numbers haven't been improved on very much. We were able to get a rejection at ten minus fifth, using lead glass and a shower technique, and sampling showers and so on. The nice thing about electrons is that the resolution is very high. The mass resolution, because you don't have any material in there. On the other hand, the disadvantage of electrons is that along with the electrons there is an enormous counting rate of pions that are coming into the apparatus that you have to reject. So the rates are limited. I think at that time, the group opted for mass resolution. I think our first runs were with electrons.
Right, the so-called EE1 phase.
I do remember that we made a brief excursion to muons. And did we go back to electrons? We may have gone back to electrons again.
EE2 phase, 494 intervened.
That's right. That's when we saw this fake [???] at 6 GeV about 12 events. We had one or two that John Yoh caused to label [???] a bottle of champagne in the refrigerator. Then we said, to really track this down. By this time, we'd gotten a good feeling of the pros and cons of both. We were joined somewhere around there by Steve Herb who was a postdoc had come from Cornell. He was especially forceful. I would say we had four very good postdocs. John Yoh, Herb, Innes, and the Japanese guy.
Ueno and then Chuck Brown of course was the straw strong horse. Those guys, we started saying, "look we've got to break through this thing and the way to do it is get as big a solid angle as possible. Let's be very careful in the shielding. Let's take meticulous care to avoid cracks, because that's how you limit the rates." And so we designed a super shield. We got all the beryllium in the world we could find to keep the multiple scattering, the inevitable multiple scattering down.
And so the trick really was that we'd finally learned how to do this sitting in the beam for god knows how many years, pennydrop, if you like, funnily, we just took a bulldozer, figuratively and put all the key moves, all the apparatus as close to the target as we could. Did an extremely meticulous job of shielding. And in fact the [???] was astounding, whereas total accumulation of [???] events was a few hundred in the world. We had approaching 100,000 [???] events when we finally quit that run. Then we found the bump that brought the upsilon in about 7000 events or so.
Could I ask you about the 6 Bev? Do you remember the discussions within the collaboration?
Yes. Again there was statistical questions. I remember doing the the statistics myself, to try to find out how often we get twelve events clustered together within the range of the random number of processing of [???]. It looked to me like there was a fifty to one shot. That's just 2%. That sounded like good odds to me that there was something there. I think I carried the group with my enthusiasm. The paper was carefully worded, I have to say. I'm not just saying, maybe it's not there, but it certainly looks against the [???] looking for [???].
I've heard that some people in presenting these results in talks before the paper went out, were a little less cautious about the significance of...
Some might have been.
Do you remember if you gave talks at that point?
sure, I gave talks all the time. I think when we have the effect we debated a lot and we knew that this was just the kind of fluctuation that can happen much more often than 2%. These states of deviations happened all the time. On the other hand, it was sort of fun to pointing out that there might be something there, some [???] who might presenting it as if something is there, that is natural, a human trait.
You hadn't given a name for this suggested [???]
If we had been more conservative, we wouldn't have given it a name, we would have said, there's some indication of something here. So, we were strong.
People wouldn't have paid as much attention?
Well, that's for sure. But very quickly, because we said there's something there, almost by return mail we got data from SLAC survey that we do by scanning through it, not seeing anything. That already gave us pause. We were working hard on the muon version to confirm that. The muon version didn't confirm it.
That was the mu mu 1.
And then the largely, I understand Stony Brook effort in the 494 di-hadron.
That was McCarthy.
Do you remember that as delaying your mu mu 2?
That's a good question, did it delay it or not?
I know there was discussion about when to end. It was ended in late February of 1977. When to end 494 and go in to the mu 2. I wondered if you remember those?
I wasn't too involved in that. McCarthy of course, was very committed to that particular experiment and we had put in our program so we went through with it. We were very much wanting to put the best in the field. There was still a possibility that you could see this in the forward reaction and not have to find theoretical ways to invent something, that would show up in one direction and not in the other direction. It was pretty bizarre. So, I think in the end we had to, on our own, in our own experiment see if we could confirm that or not. That's right, I'd forgotten that 494 was also on the program.
In these years, you were director at NEVIS?
You were also working on a CERN experiment?
Do you remember which [???]
Teaching…and committees of various kinds.
How much time did you have for 288?
That's a good question. On a relative basis, usually you get what you hope is that with all your different activities, don't go critical at the same time. You're always doing three things at once in the research business. You're writing up the last experiment, you're proposing a new experiment, and you're running the one you're doing now. That was a way of life, which goes all the way back. At the same time, we were doing the two-neutrino experiment at Brookhaven, I was doing a very hard experiment at NEVIS called new capture in hydrogen. It's two hours to get back and forth between the two labs. I'd shuttle back and forth like a ping-pong ball. This was the days in which you could work seventy or eighty hours a week and move along for a long time. On 288 I spent [???], there was a good group here. There was the design of it, the running of it, looking at the data and so on. I spent a lot of time, had a little house in the village. The peak of the CERN activity was really in '72. I spent a sabbatical year at CERN. At that time, they were impatiently waiting for me to be here, I was pretty busy at CERN. From then on, my CERN run was done in a month here, or two weeks here. I think in 1976, I probably spend another 6 months, maybe 1975, 1976, maybe it was later. That was a hot time and a lot of work.
So, 288 continued taking data. That was of course, the summer of 1977 the discovery was announced...
I think we started running, we got a fire. Which we'd already seen them with the bump. We thought that was a phenomenon, which we got back on the air in a week. By June we were ready to announce it and Steve gave the talk here at Fermilab, in the joined Auditorium and we kept on that, improving the resolutions and getting more data and working very hard at the tails to see if there's any else out there. And then we also did a very thorough. I remember a lot of work on the [???] continuum, on how to correlate the structure functions, sort of the bread and butter part of it, since we were looking at the structure functions in a totally different way that people in elastic scattering were doing a third experiment in neutrino scattering is one thing. Muon scattering is another. Those are sort of exploring the space light components and then producing pairs of muons looked at exactly the same phenomenon, which was how are the quarks moving around inside the proton. We were able to use the measured structure functions and confirm them really remarkably well, which was an amazing thing and then polish up a little bit on the knowledge of muon structure functions, for which we had somewhat of better handle at the time. Another thing is scaling. We did a lot of data in which the [???] off, in addition to the bumps.
Could I ask you briefly to tell me how you got this beryllium?
That’s a good question. I think we got most of it from Oak Ridge. It was used in I'm not sure exactly. It was used in bond processing. Some of the shapes we got were classified. Classified shapes, most of them were in blocks. Beryllium is not a trivial thing to machine, you've got to use hoods and so on the beryllium dust is a no no. That had been learned during the war in the weapons labs. Beryllium is an important shielding device. High density. We got most of it from Oak Ridge.
How was that connection made? Had you heard?
Yes. That's the governments surplus. If we went out and bought it, we'd get killed by the price. I was a great telephone physicist. I would call up.
You knew somebody there at Oak Ridge?
Sure. That helped. A lot of this kind of procurement works by that technique.
I know that with 605 the NEVIS-cyclotron was used [???]
I think they were trying to collect all the cyclotrons, only some of them got away.
Tell me when you need to stop. In 605, teams from CERN and Saclay and Kyoto and Washington were added. Can you tell me something about that.
Design were flushed with the success of 288. We said what do we do next. This must have been 1978, early 1978. We said, "If we want to pursue this subject out to higher masses with greater sensitivity, let's do it that way." So we designed a spectrometer that would have much better resolution. We wanted an open geometry rather than having all these acres of beryllium and so on, which inevitably cause multiple scattering. We knew we had to have reasonably big acceptance if we wanted to take an intense beam, so we designed that 605 spectrometer which had a long magnet.
Who were you working with mainly on that design?
It was the 288 group. Chuck Brown was again the chief guy from the Fermilab team. [???] was still involved in 605.
McCarthy was important in that. Kaplan was there.
This was really the group that was on 605?
My idea at the time, in fact, was inspired by an old Steinberger focusing spectrometer in which you used the principle that if you have a mass and it decays into two particles, the two particles will come out parallel. I wanted to use that idea of a parallel focusing spectrometer. Then you don't have to have anything close up. The main idea was not to have the detector near the target. But put them very far away. And protect the detectors by this humongous magnetic field. Have nothing upstream, nothing near the target, because that's where the fatal intensities are. The whole trick, the whole thing, going all the way back to Brookhaven was how to take high rates. The number of protons is infinite, its primary protons. The machine can kill your detector by giving ten times as much as you want and they won't even notice it, and you watch your detector die at the rates. I've seen that at Brookhaven where we restacked some shielding for us and none of the counters worked. We looked to check the high voltage, and we said, "What's wrong with the counters? They're not working." It was a small crack in the shielding they had left, produced so many neutrons and stuff that it just disabled the counters. I remember Christiansen finding the crack and took a big chunk of plywood and jammed it into the crack and you could see the counters starting recovering. We had a lot of experience and that's why I'm very amused at the SSC and the problems of how do you do 100 megacycle counting. I've spent most of my life trying to live at ever higher bombardment levels.
So, were you working with Sepac?
Yes. That was our guy at Fermilab on the fast electronics.
Finding out what was possible?
Yes, exactly. So this spectrometer was designed in order to keep the counters as far away from the lethal rates as you can come, but not give up any resolution. So, we said, "Okay, we know what the target is, and then if we get enough information downstream, we can plot the trajectory and gain the resolution of this big magnet. Large bending in the big magnet." Then we'd have good acceptance, because it was focused.
When you were designing it had you already thought of using the Nevi-Cyclotron for that magnet?
No, in the original design in fact there were two magnets. That's why it's called 1, 2. Because there was a µ and then there was µ too. In fact, somebody else said we should join those two magnets together. And then we looked around for iron and decided to try [???] at that time, it had been closed down, just sitting there not doing anything. We turned that over to the engineers. Once it was approved.
And you could see that you needed more people on a big experiment that size?
Sure, it was a bigger experiment, we also wanted to do hadrons, pick up the CERN guys to contribute the Cerenkov counter technology. Charpak, an old friend of mine.
It was through Charpak that CERN and Saclay teams joined [???] How did you know him?
Charpak I knew since 1957, European stuff. He worked me on G minus 2, experiment I did at CERN on the first sabbatical in 1959.
So, you knew he was working on that kind of a detector?
We hadn't been together for a long time, so I interested in this particular challenge of particle [???] of very high momentum separated pi's and k's in 200 Gev.
And he brought in the Saclay people?
He brought in some of the Saclay people. Some of them came in a different way. I think that's when, what's his name, the American, Hubbard. I saw him just two days ago.
You were just telling me there was a second way of the Saclay team.
There were two... One group... never joined the experiment, he is the guy who really invented this, as far as I'm concerned, this ring energy device. He was at Saclay at the time. And George was part time at Saclay also. The other group came in through [???]. somebody had spent some time at Saclay, maybe it was McCarthy, he recruited Hubbard and his people.
What about the Japanese? How did they get involved?
Probably. Good question!
If it helps here's a list.
I think it was mostly through Miyake, who was a good friend of Yamanouchi. It was a [???] Japanese-American. They went to school together. The Kyoto group were students and postdocs of Miyake who was a professor in Kyoto. At that time, also, let's see by this time, about 1979 was the new US Japanese agreement, which I helped to negotiate on collaboration of high energy physics, in which the Japanese not only contributed people, but money to the experiment.
Was that a coincidence that you helped to negotiate that agreement?
Yes. More or less a coincidence. I'm trying to remember. The first negotiation took place just after the Tokyo conference. It must have been 1978. So, I was not in any official position except for just the beginnings of gray hair. I know I was called back from visiting in Korea to hole up in a hotel in Tokyo and help find out the components of this agreement that they called the Fukuda initiative. Starting with Fukuda visiting Jimmy Carter, he was a prime minister. Sort of the same things going on now, just changing the Japanese, feeling guilty about robbing us... about the balance of trades, decided that they would make contributions to join in the efforts. High energy physics was somehow squeaked in as one of the four components, one was solar energy, coal gasification, of which the Japanese couldn't care less, since they didn't have any coal. We got along fine with the Japanese and we had our agreement all sewn up within a day, whereas the other were in terrible trouble.
Did you have anything to do with high energy physics being included as one of those areas?
We helped. The under secretary of energy, a man by the name of John Deutch, I knew him and somehow we said this is an important issue and we had a very strong Japanese guy, Misako who is the director of KEK labs was very effective in convincing the Japanese side.
What about the Washington [???] for 605?
John Rutherford was there and a very old friend of mine, Bob Williams, who was the senior guy in the experiment, didn't show up all too much. He was busy doing other things, too. But through him, we got a good group of people, of whom John Rutherford was the...
So, how does that work? You can see that this is a big effort and you need more people on it?
You get on the telephone and you call up friends that you think might be interested or you run into them at meetings. If we go, we should take a walk and look at the board in the [name] meeting room and you'll see the actors in the various experiments. You'll see a strange and wonderful thing. Athens and Greece and Helsinki and Harvard. How the heck did these guys get together? I think there's just a network. The noble nature of things. Graduate students graduate and off they go to other places. And then they call. A graduate student gets an idea and he's no longer a graduate student and he calls his old professor and says, "How would you like to join me in this thing." So in the early days, as this is a transition from the two or three man experiments, somewhere I plotted a graph of how the number of people in experiments start to exponentiate, to getting 16, 18, 20, 30, until you have 30 person experiments, not a small cozy intimate group [laughter].
You said the case that you have some idea when you draw up this proposal how many people it will take and you keep at this until you get those?
It's not only people, it's resources. People plus each group you get brings a certain amount of resources, skill in computing or skill in electronics, or skill in making something. Often that will point you to a group and what we need is someone who really knows about this projection chamber. Every group that comes in brings financial resources for the experiment, and that's also important.
At some point, you decide you've got enough?
Sure. We did not want any more, we had enough people to do the experiment.
605 was moved to the meson lab. Why was that?
I have one possible reason. I'm not sure that was the definition. We had some ideas that maybe we were also wanted to use pions and kaons, rather than protons. That was a possibility.
In fact, that was to be phase II of 605.
That's right, that couldn't be done in proton. There was very limited area in general. We probably would do better off in the meson, there was a lot more flexibility.
You mean physically?
The 605 detector took [???]
Certainly that would be another thing. It certainly filled that hall in the same… So the lab I think encouraged a re-shuffling, so that they could devote that area to hyperon. We won a beam that had a better geometry and to control more tiny spots and all these things that makes the optics better.
One of the objectives of 605 was to search for a [???] [???] in the proposal.
It might have been.
In looking back at these experiments.
[???] as long as the top quark in a civilized mass.
You're going to new energies in 605. In looking back at it, what is it, what was the contribution of 605?
Well, it scanned the [???] main to the limit for the number of the machine’s ability to provide particles. That it did very well did not see the [???]. Nothing beyond these two peaks. It added to our knowledge of the upsilon and may hadronic collision at that point. Creating a very, very [???] peak. Looked in between them with more sensitivity for hidden bumps that might have been there. In fact, it was a search experiment, it was pretty incisive. Later, it was able by accident to set to rest the possibility of a low mass axiom that might account for the QSI [???] in the German energies [???]. Again [???] result produced more data on the hadrons, about hadrons, and looked at the hadron mass spectrum, [???] [???] The most spectacular results from that series of experiments. Then it got changed to 772, the same apparatus. [tape interrupted]
One of my questions is whether 772 really belongs in this string of experiments.
Well it's a drellian. Very much it's a drellian. It's using a drellian process for which that spectrometer is uniquely suited in order to study the very soft components of the quark structure functions which the nuclear physicists are interested in and look at the dependents of that. So, I think it is an experiment, very much so, in that sense. Look at one pair and at that kinematic domain where you have one large X and one small X. The small X would generate at a place where quarks might forget. But in the nucleus, which nucleon they belong too when you're were looking for effect, nuclear effect of an electron. That was pushed by the Los Alamos people.
There's an advisory committee which helped us select what experiments to look at. They did not include 772 and 789.
789, I'm back on that experiment. I haven't been doing much work. I had a postdoc on it and hope to begin to get more active in some… 789, again makes use of the power of that spectrometer. Again it's the rate capability that 605 demonstrated that you can take an open geometry something like 30 collisions, or a bucket, which lasts for a nanosecond, you get 30 collisions in a nanosecond and those buckets occur every 20 nanoseconds, so that's 50 megacycles, times 30, whatever that product is the number of interactions that it can handle. That's a very, very large number of interactions. And in physics, that's the name of the game. How you can stand very, very high rates? Because you make 1 beauty and ten over sixth interaction. It makes use of the spectrometer, but of course, it's a two particle spectrometer, so for the price you pay you're only going to look at the two body decays of the B's ratio, but if you get those rates, can achieve those rates, then you have a very sensitive experiment, relatively for finding a few hundred B's in various channels of the two body decay mode. Philosophically you're quite right. It's not a drellian type experiment that 772 was.
I haven't really looked at 772 and 789. Are they using the same spectrometer?
Not only the spectrometer, but the same electronics, the same coffee pot. Each one, though, brought in something different. In 789 the big addition is some bits of silicon which have to survive near the target. To see the beauty quark in that background, you've got to say, I've got two bodies, they add up to the correct mass of the B, capital B, and the vertex is in the vacuum. If you don't add that, then you'll be swamped with a continuum of masses, hive of B's. You've got to have the vertex in the vacuum. That's the job of the silicon. Whether the silicon will survive, that's the new addition that has to work. That's the biggest risk of the experiment. [???]
So, the spectrometer wasn't modified a great deal for those two.
Either of them. Very little. Even the electronics was sharpened up and repaired and some modified. Most of the original Sepach [?] electronics is in there.
What about software from 605?
A lot of it is still there. Maybe you should ask Chuck Brown, or Dan Kaplan there is a lot of same people.
Not that many, actually. There's Chuck Brown and Dan Kaplan, but that's almost it, going from 605, to 772, to 789. That was a question I had. Why, if you look at the teams on 772 and 789, you know the continuity is Fermilab. And even with the Fermilab people, it's really Chuck Brown.
Childress, Cooper, those guys. [???] is a graduate student of mine who went through the...he's a holdover. Bob [???] is the green on that. Mark Adams is a holdover from 605. The Los Alamos group are all new, you're right.
I think what's happening is that these list I'm looking at are 605 at one stage and don't pick up many of those people.
Mark was certainly a 605 guy. I'll make a little check on the 605 people I think. Then we have McCarthy and Adams. So, one, two, three, four, five, six, there were seven holdovers here. On 789, that's probably these three. Another student of mine joined, George Giddal and there's Kaplan. Now you're down to only four people. My name isn't here. So it's five.
So, you have been on these from Brookhaven days up 'til 789.
772 I skipped. I worked, I took shifts, when I was director, I took shifts on 605 for a fair amount of the time. Soon as that was over, I sort of stopped.
Were there proposals along the way in this 20 year period that were not accepted your group made?
I don't think so. Maybe we got talked out of it, before we made the proposal. I think I can't remember anything that was turned down. I was worried about 605, because from the time I designed it and until the PAC got to it, I'd become director. I'd warned the guys who hired me that I would probably continue to do the search. They were a little shocked, Ramsey doing the search. I said, "It's got a lot of advantages."
Did you feel you had to disassociate yourself from 605?
During the approval phase. They know I'm part of it and so on. It inevitably had to. I'm not so sure. Those guys are pretty tough. A physicist, especially in front of [???] committee can be nasty. These are outsiders, outside the lab, critics that are outside the lab. You know, it was a natural experiment, a follow up on 288, a better spectrometer and so on. A little bit, sort of like a repeated neutrino experiment, where the second neutrino experiment is much more expensive, much more involved and didn't do much, looking back at it, compared to the original discovery which motivated that line of research. The third generation of neutrino experiments was totally different. Both at CERN and here. That got you for the domain and the Steinberger program at CERN had lab written neutrino physics. Humongous 2 mile long bubble chambers and here was one of the first proposals that was Kline, Mann and Rubia[???]. The Avis[???]version of that at Caltech. Those were very sophisticated things with multi-hundred ton detectors. At that time the sophistication was really mushroomed. That's when all the good data came out on neutrino scattering. Neutrino scattering essentially photographs the protons. With neutrinos it tells you what the quarks are doing. That was a very fruitful kind of research.
This twenty year span that we just looked at Fermilab from 1970 on, there's continuity of four or five people through most all of that. Some continuity in the equipment.
605 was a break. Everything up to 605 really used a lot of the same equipment. When it was electrons, there was always the lead glass arrays which we had learned how to do that at Brookhaven. We had become experts on leadglass by doing, by sitting at the Brookhaven beam for six months. We used, brought that technique to CERN in which, in fact, in some sense. It was generated I think at CERN. The first leadglass was at CERN. We heard about it, elaborated the technique, learned how to be skillful with this stuff and then brought a big array to Brookhaven and a big array here. A big array at CERN and a big array here. So that was always used. The electronics was used in proportional wire chamber stuff that had been invented by Charpak. The read-out, the NEVIS read-out is essentially copied widely, we could always borrow that stuff if we lost it. Everybody's using Sepach's read out. He did it, but it was motivated by our experiments which had the wire chambers.
Do you think this is fairly unusual to have that long string of experiments?
No. Again let me look at some of my colleagues. Steinberger got into the neutrino business of course in the original experiment then he essentially immigrated to CERN and started a program of neutrino physics, which meant for many, many years. At the same time, the same guy started a series of neutral kayon experiments, which again were very definitive experiments. A whole series of beautiful experiments on neutral kaon, culminating in the present disagreement with Fermilab, this part parameter upsilon prime. The two groups disagreed in somewhat significant way. But that's a whole series of experiments illuminating this complex structure of particle ??? physics. Again that took almost twenty years... neutral kaons started in 1958. Then CP violation in 1965. Since then it's been steady... so, he's been regarded a particular in one end the neutrino and in the other end the neutral k's for a long time. Who else? Well again, if you look at the...all of this, all of this is sometimes connected, is often connected with accelerators and detectors. Look at the Stanford work on +E — collisions or the Cornell work. In some sense that's a program for which you can... talk about the facility if you like. You can see some continuity in that kind of program. The evolution[?], spear and then PAP and then SLC.
It's interesting here that you changed beam line here and there's a fair change during the first ten years, not much change. Since then quite a change in what groups are in on the experiment, but still quite a measure of continuity. I have two smaller questions that go back to quite a bit earlier. One was about teams detectors that got used. I believe in the mu mu 2 phase of 288. Am I wrong about that? I was told that there were a couple of detectors that had been used by Ting [?] that were borrowed.
Do you know what they looked like? There might be some jokes in that. Ting had been at Columbia and when he went to do his experiment in Daisy, he borrowed a lot of equipment that never came back. That was a standard joke that if we run out of equipment, we can go find some in Ting's cupboards at Daisy Lab. I don't remember borrowing.
The other question was how the Stony Brook group got added for 494. I know one connection was Hans Jöstlein. Did that work that? I was just wondering, did you have other connections with Stony Brook people, Bud Good, or [Bob] McCarthy?
Good I knew from old days. McCarthy, no, I didn't recruit McCarthy. He somehow showed up.
Did you recruit Good?
I don't think so. They just showed up.
I asked Jöstlein about this and he suggested I ask you. He wasn't sure. He thought there might have been another connection.
Was he actually at Stony Brook for a while?
Because I knew him from G minus 2 when I was at CERN.
I know how he was added. He thought that the other Stony Brook people were added in some other way.
Yes, that's a good question. I don't know who recruited. McCarthy was the key guy there. He certainly wasn't recruited by me. It must have been someone else. Maybe it was Chuck Brown, have to go back to his antecedents to see where he came from.
Those are the questions I had at this stage. We're also very interested in what records are around from these experiments. We've been asking other people what they have. I wonder what you personally have?
You know about the sign [?] of the American article. Other than that I have a reasonably...just behind you...collection of the publications.
What about your personal things?
I have very little of that. Whatever I have that's movable was shipped up to Adrian's place. She is my archivist. Whether there are any notes. So, everything was put in boxes and sent up there. I don't have anything that I didn't give up there that isn't in these things. You tend to accumulate so much stuff that you just Stan [???] a lot of my NEVIS stuff which I thought was safe there, got lost. Some of it may be here. I don't know how much is there.
You mean at NEVIS?
Yes. The lady who knows is Ann Therrian [?]. She sort of in the traditional sense runs NEVIS. She may have some... Log books and so on I never kept.
I was up with Chuck Brown looking for log books. He said that one or maybe more were presented to you.
Yes, that's true. What did I do with them?
We couldn't find actually the mu mu 2 log books.
Is that right?
He knows that at least one, maybe I remember wrong.
I think what they presented me was the log book in which we saw the guy [name] and [name] saw ??? show the first bump in 288. The earlier books I would have no idea what happened to them.
It's one log book you have?
I remember the presentation we were at the party and so on, and they gave me the book and so on and people snapped picture. What I did with it is another question. Maybe we put it in the famous box that Adrian has. That's a good question. I'll have to search for that. I move from a big office to small office and anything I didn't want I just sent up there. I wouldn't even know where to look. I'll look around the house. There may be some things in the farm house here, since we're still living there. I didn't take anything down to Chicago that wouldn't be useful.
But most of your papers that you have here were in those boxes that you gave to Adrian?
Anything that I thought was the least useful I gave to Adrian, and a lot of stuff that's not useful.
Thank you very much. I have to ask you while we have the tape recorder going, if we have your permission to use this interview as part of the AIP study.
And the second question, if we have your permission to put the transcript in the AIP archives at the conclusion of our study.