Strong field processes in beam-beam interactions at the Compact Linear Collider

The demand for high luminosity in the next generation of linear ${e}^{+}{e}^{\ensuremath{-}}$ colliders necessitates extremely dense beams, giving rise to strong fields at the collision point, and therefore the impact of the field on the physical processes occurring at the interaction point must be considered. These processes are well described by the interaction of the individual lepton with the field of the oncoming bunch, and they depend strongly on the beamstrahlung parameter $\mathrm{\ensuremath{\Upsilon}}$ which expresses the field experienced by the lepton in units of the critical field. In this paper, we describe calculations and simulations of strong field processes---also of higher order---at the interaction point.