The mono-Higgs + MET signal at the Large Hadron Collider: a study on the $$\gamma \gamma $$ γ γ and $$b\bar{b}$$ b b ¯ final states

Abstract

Abstract We investigate the potential of the channel mono-Higgs + missing transverse energy (MET) in yielding signals of dark matter at the high-luminosity Large Hadron Collider (LHC). As illustration, a Higgs-portal scenario has been chosen, where an extension of the Standard Model with a real scalar gauge-singlet which serves as a dark matter candidate. The phenomenological viability of this scenario has been ensured by postulating the existence of dimension-6 operators that enable cancellation in certain amplitudes for elastic scattering of dark matter in direct search experiments. These operators are found to have non-negligible contribution to the mono-Higgs signal. Thereafter, we carry out a detailed analysis of this signal, with the accompanying MET providing a useful handle in suppressing backgrounds. Signals for the Higgs decaying into both the diphoton and $$b{\bar{b}}$$ b b ¯ channels have been studied. A cut-based simulation is presented first, optimizing over various event selection criteria. This is followed by a demonstration of how the statistical significance can be improved through analyses based on boosted decision trees and artificial neural networks.