LEAR physics program

The ideas for the construction of LEAR (Low Energy Antiproton Ring) were presented at the CERN Intermediate Energy Workshop of 1977. LEAR, a stretcher ring for low energy antiprotons, is a part of the CERN antiproton complex. The extraction momentum ranging from 100 to 2000 MeV/c (presently 200-1600 MeV/c) is performed in one hour long continuous spills with 100% duty cycle and an expected intensity of 106 anti p/s (presently proportional3.6x105 anti p/s). The anti p beam extracted is divided in three branches working simultaneously. Each branch can be switched in two areas by swipping magnets. The beams can be focalized within a spot of 0.3x1.25 mm2, and have no pion or kaon contamination. The quality of the anti p beams obtained with LEAR is several orders of magnitude better than the secondary beams of anti p obtained without accumulation and cooling. It allows a rich physics program to be performed in several fields such as on rare annihilations, strong interactions, CP violation, atomic physics and nuclear physics. (orig./HSI)