TRILEPTON HIGGS-BOSON SIGNAL AT HADRON COLLIDERS

Most Higgs boson searches pursued at hadron colliders require Yukawa i nteractions either in the production or the decay of a Higgs boson. We propose a trilepton Higgs boson search based only upon the gauge inte ractions of the Higgs boson. This strategy can be utilized successfull y for the standard model (SM) Higgs boson as well as nonstandard Higgs bosons which break electroweak symmetry but have little to do with fe rmion mass generation. The trileptons come from Wh production followed by Wh-->WWW()-->3l decays. A SM Higgs trilepton signal would be diff icult to detect at the Fermilab Tevatron collider: with 100 fb(-1) of data, only a 3 sigma signal above background can be achieved after cut s if 140 GeV<m(hsm)(0)<175 GeV. Some discrimination of signal over bac kground can be gained by analyzing the opposite sign dilepton p(T) dis tributions. At the CERN LHC with 30 (100) fb(-1) a clear discovery abo ve the 5 sigma level is possible for a Higgs boson mass in the range 1 40-185 (125-200) GeV. Prospects for a trilepton Higgs boson discovery are greatly improved for models with nonstandard Higgs boson sectors w here a Higgs boson couples preferentially to vector bosons rather than to fermions. [S0556-2821(98)01709-3].