Number 61 (Story #1), January 3, 1992 by Phillip F. Schewe and Ben Stein B-QUARK BARYONS HAVE BEEN DISCOVERED in data recorded at the CERN proton-antiproton collider. The UA1 collaboration, which discovered the Z and W bosons in the early 1980's, has been sifting collision events ever since and has compiled a sample of about sixteen rare events in which a lambda-b (a proton-like baryon containing a b quark) is created in proton-antiproton collisions; after this the lambda-b decays into a J/psi meson and a regular lambda baryon. Mesons with b quarks had been observed previously, but not baryons. On the basis of the UA1 sample of events, the mass of the lambda-b is estimated to be about 5600 MeV. (CERN Courier, Dec. 1991.)