A Theoretical Model and Computer Simulations to Describe Diffusion Enhancement by the Beam-Beam Interaction

Several observers have speculated that the simultaneous presence of diffusion processes and the beam-beam interaction may lead to enhanced diffusion or beam loss greater than that present with either diffusion or the beam-beam interaction alone. To test those ideas we have developed analytical and numerical methods to estimate the magnitude and variation of this enhancement. We find substantial agreement between simulation results and our theoretical model that describes diffusion enhancement caused by a major resonance located within the beam. In this paper, we present results of beam-beam simulations with random diffusion which systematically cover fractional tunes between 0.0 and 0.5 and tune shifts between 0.0 and 0.10. Our theoretical model is tested systematically, and is found to provide an adequate approximate description of the phenomena.