Super Proton–Antiproton Synchrotron
Carlo Rubbia and Simon van der Meer received the 1984 Nobel Prize in Physics for their contributions to the SppS-project, which led to the discovery of the W and Z bosons.
Around 1968 Sheldon Glashow, Steven Weinberg, and Abdus Salam came up with the electroweak theory, which unified electromagnetism and weak interactions, and for which they shared the 1979 Nobel Prize in Physics.
[3] The second stage of establishing the electroweak theory would be the discovery of the W and Z bosons, requiring the design and construction of a more powerful accelerator.
[7] In 1972 Simon van der Meer published the theory of stochastic cooling,[8] for which he later received the 1984 Nobel Prize in Physics.
Meanwhile, the discovery of neutral currents in the Gargamelle experiment at CERN triggered Carlo Rubbia and collaborators proposal for a proton-antiproton collider.
The requirements of a storage ring as the SppS, in which beams must circulate for many hours, are much more demanding than those of a pulsed synchrotron, as the SPS.
Antiprotons were produced by directing an intense proton beam at a momentum of 26 GeV/c from the PS onto a target for production.
The emerging burst of antiprotons had a momentum of 3.5 GeV/c, and was magnetically selected and steered into the AA, and stored for many hours.
The main obstacle was the large dispersion of momenta and angles of the antiprotons emerging from the target.
Simply put it is a feedback system based on the fact that all beams are particulate and that therefore, on a microscopic level, the density within a given volume will be subject to statistical fluctuations.
[3] In the PS the antiproton bunches were accelerated to 26 GeV in the opposite direction of that of the protons, and injected into the SppS.
The injections was timed as to ensure that bunch crossings in the accelerator would happen in the center of the detectors, UA1 and UA2.
It would then pass into storage for 15 to 20 hours of physics data-taking whilst the AA resumed accumulation in preparation for the next fill.
The SppS occasionally ran pulsed operation after 1985, obtaining collisions at a center-of-mass energy of 900 GeV.
[13] The SppS began its operation in July 1981, and by January 1983 the discovery of the W and Z boson by the UA1 and UA2 experiment were announced.
Carlo Rubbia, spokesperson for UA1 experiment, and Simon van der Meer received the 1984 Nobel Prize in Physics for, as stated in the press release from the Nobel Committee, for "(...) their decisive contribution to the large project, which led to the discovery of the field particles W and Z (...)".
Before the SppS was commissioned, it was debated whether the machine would work at all, or if beam-beam effects on the bunched beams would prohibit an operation with high luminosity.
[6] The SppS proved that the beam-beam effect on bunched beams could be mastered, and that hadron colliders were excellent tools for experiments in particle physics.
In such regard, it lay the ground work of LHC, the next generation hadron collider at CERN.
