Simulation of Beam-Beam Lifetime for LEP’

A program that uses a new technique to simulate the beam halo in circular e+e- colliders is applied to the LEP. This technique makes it possible to investigate tail particle behavior in reasonable CPU times. The program now includes four interaction points and errors at or between the IP’s. Analytical analysis shows that the errors break the symmetry and introduce extra low-order resonances that are forbidden by symmetry. Simulation results show the expected phenomenon. Another effect, the quadrupole mode coherent motion of the strong beam, is also studied. I. INT+R~IXJCTI~N A simulation methodI*] was proposed to look into rare particles in the beam tail (halo) while saving a factor of hundreds, or even thousands, on CPU time as compared t