MINIJET VETO - A TOOL FOR THE HEAVY HIGGS SEARCH AT THE LHC

The distinct color flow of the qq --> qqH, H --> W+W- process leads to suppressed radiation of soft gluons in the central region, a feature which is not shared by major background processes like t ($) over bar t production or qq --> W+W-. For the leptonic decay of a heavy Higgs b oson, H --> W+W- --> rho(+)nu rho(-)($) over bar nu, it is shown that these backgrounds are typically accompanied by minijet emission in the 20-40 GeV range. A central minijet veto thus constitutes a powerful b ackground rejection tool. It may be regarded as a rapidity gap trigger at the semihard parton level which should work even at high luminosit ies.