Beam background with beam–beam effect at BEPCII collider

Purpose The beam-beam interaction can change the beam distribution, especially at the interaction point, which is a critical factor influencing the cross section of Touschek scattering. Studying the beam background with beam-beam effect will enhance our understanding of the beam background during collisions.
Method A new beam dynamics code which could support strong-strong beam-beam interaction in realistic lattice tracking is used in the background simulation study. The impact of the beam-beam interaction on the beam background simulation and experiment at BEPCII is quantified both with and without beam-beam effect.
Results The simulation result shows that the inclusion of beam-beam effect leads to a decrease in the beam background by approximately 20%, which is consistent with the trend of experimental observation. Since the beam dynamics tracking is more accurate with self-consistent lattice tracking and collision simulation, new tools and methodologies are expected to increase the accuracy and prediction capability of the background simulation, which would contribute to the related study in future e⁺e^- colliders.