Searching for Heavier Higgs Boson via Di-Higgs Production at LHC Run-2

Abstract

The LHC discovery of a light Higgs particle $h^0$ (125GeV) opens up new prospect for searching heavier Higgs boson(s) at the LHC Run-2, which will unambiguously point to new physics beyond the standard model (SM). We study the detection of a heavier neutral Higgs boson $H^0$ via di-Higgs production channel at the LHC (14TeV), $H^0\to h^0{h}^0\to W{W}^{\ast }\gamma \gamma$. This directly probes the $Hhh$ cubic Higgs interaction, which exists in most extensions of the SM Higgs sector. For the decay products of final states $W{W}^{\ast }$, we include both pure leptonic mode $W{W}^{\ast }\to \ell \bar{\nu }\bar{\ell }\nu$ and semi-leptonic mode $W{W}^{\ast }\to q{\bar{q}}^{\prime }\ell \nu$. We analyze signals and backgrounds by performing fast detector simulation for the full processes $pp\to H\to hh\to W{W}^{\ast }\gamma \gamma \to \ell \bar{\nu }\bar{\ell }\nu \gamma \gamma$ and $pp\to H\to hh\to W{W}^{\ast }\gamma \gamma \to \ell \nu q{\bar{q}}^{\prime }\gamma \gamma$, over the mass range $M_H=250-600$GeV. For generic two-Higgs-doublet models (2HDM), we present the discovery reach of the heavier Higgs boson at the LHC Run-2, and compare it with the current Higgs global fit of the 2HDM parameter space.

Comments: Phys.Lett.B Final Version. 16pp (9 Figs + 4 Tables). Only minor refinements, references added