In SUSY models with heavy squarks and gaugino mass unification, the gaugino pair production reaction $pp\to {\tilde{W}}_1^{\pm }{\tilde{Z}}_2$ dominates gluino pair production for $m_{\tilde{g}}\gtrsim 1\mathrm{TeV}$ at LHC with $\sqrt{s}=14\mathrm{TeV}$ (LHC14). For this mass range, the two-body decays ${\tilde{W}}_1\to W{\tilde{Z}}_1$ and ${\tilde{Z}}_2\to h{\tilde{Z}}_1$ are expected to dominate the chargino and neutralino branching fractions. By searching for $\ell b\tilde{b}+{\mathrm{E̸}}_T$ events from ${\tilde{W}}_1^{\pm }{\tilde{Z}}_2$ production, we show that LHC14 with $100{\mathrm{fb}}^{-1}$ of integrated luminosity becomes sensitive to chargino masses in the range $m_{{\tilde{W}}_1}\sim 450–550\mathrm{GeV}$ corresponding to $m_{\tilde{g}}\sim 1.5–2\mathrm{TeV}$ in models with gaugino mass unification. For ${10}^3{\mathrm{fb}}^{-1}$, LHC14 is sensitive to the $Wh$ channel for $m_{{\tilde{W}}_1}\sim 300–800\mathrm{GeV}$, corresponding to $m_{\tilde{g}}\sim 1–2.8\mathrm{TeV}$, which is comparable to the reach for gluino pair production followed by cascade decays. The $Wh+{\mathrm{E̸}}_T$ 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 $+{\mathrm{E̸}}_T$ channels.

• Received 18 January 2012

DOI:https://doi.org/10.1103/PhysRevD.85.055022