Electroweak Physics at the Cern p̄ Collider

The conversion of the CERN SPS into a p̄ Collider was motivated by a very specific goal,1 namely the discovery of the Intermediate Vector Bosons (IVBs), W± and Z, which were postulated to mediate the electroweak interaction.2 The p̄ project was approved in June 1978, and the first p̄ collisions at a total centre-of-mass energy of $$ sqrt s = 540\,GeV $$ were observed in July 1981.3 In less than two years since that date, the main goal has been fulfilled. Evidence for the production of the charged IVB, the W±, and its subsequent decay into an electron and a neutrino, was presented soon after the end of the physics run which took place in autumn 1982;4,5 and the Z was discovered in the subsequent run of spring 1983.6,7 The total integrated luminosity collected during these runs by each of the two major experiments amounted to ~ 130 nb−1.