Wh plus missing-E_T signature from gaugino pair production at the LHC

Abstract

In SUSY models with heavy squarks and gaugino mass unification, the gaugino pair production reaction pp-> \tw_1^\pm\tz_2 dominates gluino pair production for m_{\tg}\agt 1 TeV at LHC with \sqrt{s}=14 TeV (LHC14). For this mass range, the two-body decays \tw_1\to W\tz_1 and \tz_2\to h\tz_1 are expected to dominate the chargino and neutralino branching fractions. By searching for \ell b\bar{b}+MET events from \tw_1^\pm\tz_2 production, we show that LHC14 with 100 fb^{-1} of integrated luminosity becomes sensitive to chargino masses in the range m_{\tw_1}\sim 450-550 GeV corresponding to m_{\tg}\sim 1.5-2 TeV in models with gaugino mass unification. For 10^3 fb^{-1}, LHC14 is sensitive to the Wh channel for m_{\tw_1}\sim 300-800 GeV, corresponding to m_{\tg}\sim 1-2.8 TeV, which is comparable to the reach for gluino pair production followed by cascade decays. The Wh+MET search channel opens up a new complementary avenue for SUSY searches at LHC, and serves to point to SUSY as the origin of any new physics discovered via multijet and multilepton + MET channels.