SPIN DEPOLARIZATION DUE TO BEAM-BEAM COLLISIONS

The effect of the beam-beam interaction on spin depolarization in a pr oton-proton collider has been studied. The employed method is based on a matrix formalism for spin advance and for perturbed betatron partic le motion in a ring. Calculations were done for a collider with one in teraction point and two installed Siberian Snakes in each ring. A matr ix for spin advance after an arbitrary: large number of turns is found . Performed study indicates that spin depolarization due to beam-beam collisions is suppressed if the beam-beam interaction is stable and if the operation point is far enough from spin resonances. Meanwhile, in the absence of snakes or under beam-beam instability, spin is a subje ct of strong depolarization. Analytical estimations are confirmed by r esults of computer simulations.