Higgs Cascade Decays to $\gamma \gamma +\text{jet}\text{jet}$ at the LHC

Abstract

Extra light electroweak singlets can dramatically alter Higgs decays by introducing additional decay modes, $h\to aa$. In scenarios where cascade decays $h\to aa\to 4X,X\ne b,\bar{b}$ dominate, the Higgs will escape conventional searches and may be as light as $82\text{gev}$. In this paper we investigate the discovery potential of the mode $h\to aa\to 2\gamma 2g$ through direct ($pp\to h$) and associated ($pp\to W^{\pm }h$) Higgs production at the LHC. Our search covers all kinematically allowed singlet masses for $\sim 80\text{gev}\le m_h<160\text{gev}$ and assumes an integrated luminosity $\text{CL}=300{\mathrm{fb}}^{-1}$. We find associated production, despite a smaller production cross section, to be the better mode. A branching ratio $BR(h\to 2\gamma 2g)\cong 0.04$ is sufficient for discovery in the bulk of our search window. Given the same luminosity and branching ratio 0.04, direct detection fails to discover a Higgs anywhere in our search window. Discovery in the limited region $m_h>120\text{gev},m_a\sim 25\text{gev}$ is possible with direct production when the branching ratio is $\text{simge}0.06$.

Comments: 8 pages, 5 figures