Phenomenological signatures of additional scalar bosons at the LHC

TL;DR

This paper explores the phenomenological signatures of new scalar particles in a two Higgs doublet model at the LHC, focusing on their decay modes, mass bounds, and impact on current search strategies.

Contribution

It introduces a detailed analysis of scalar decay channels involving a mediator S, expanding understanding beyond previous effective theory approaches.

Findings

Set new mass bounds for the scalars in the 2HDM

Analyzed decay channels like H→4W, t t̄ H→6W, and A→ZH

Assessed impact on current LHC search strategies

Abstract

We investigate the search prospects for new scalars beyond the Standard Model (SM) at the Large Hadron Collider (LHC). In these studies two real scalars $S$ and $\chi$ have been introduced in a two Higgs doublet model (2HDM), where $S$ is a portal to dark matter (DM) through its interaction with $\chi$, a DM candidate and a possible source of missing transverse energy (\MET). Previous studies focused on a heavy scalar $H$ decay mode $H \to h\chi\chi$, which was studied using an effective theory in order to explain a distortion in the Higgs ($h$) transverse momentum spectrum [16]. In this work, the effective decay is understood more deeply by including a mediator $S$, and the focus is changed to $H \to h S,~SS$ with $S \to \chi\chi$. Phenomenological signatures of all the new scalars in the proposed 2HDM are discussed in the energy regime of the LHC, and their mass bounds have been set accordingly. Additionally, we have performed several analyses with final states including leptons and \MET, with $H \to 4 W$, $t\bar t H \to 6 W$ and $A \to ZH$ channels, in order to understand the impact these scalars have on current searches.