摘要
We consider the possibility of detecting a heavy Higgs boson (mH>2mZ) in proposed γγ colliders through the semileptonic mode γγ→H→ZZ→qq̄l+l-. We show that due to the nonmonochromatic nature of the photon beams produced by the laser-backscattering method, the resultant cross section for Higgs production is much smaller than the on-resonance cross section, and generally decreases with increasing collider energy. Although continuum ZZ production is expected to be negligible, we demonstrate the presence of, and calculate sizable backgrounds from, γγ→l+l-Z, qq̄Z, with Z→qq̄,l+l- respectively, and γγ→tt̄→bb̄l+l-νν̄. This channel may be used to detect a Higgs boson of mass mH up to around 350 GeV at a 0.5 TeV e+e-, collider, assuming a nominal yearly luminosity of 10-20 fb-1. © 1993 The American Physical Society.