Minijets and large hadronic backgrounds at e⁺e^- supercolliders

Abstract

We show that the hadronic structure of the photon, along with the beamstrahlung phenomenon, leads to a very large rate of γγ→jets at e⁺e^- supercolliders. At √s =1 TeV, for round, dense bunches, we expect ~5-50 "minijet" events per bunch crossing, giving rise to an "underlying event." Thus e⁺e^- supercolliders will be "messier" than expected, unless beamstrahlung can be kept under control.