The impact of additional scalar bosons at the LHC

TL;DR

This paper explores the phenomenology of additional scalar bosons at the LHC, proposing models with new scalars and analyzing their potential signatures, including distortions in Higgs distributions and multi-lepton events.

Contribution

It introduces a comprehensive effective model with new scalars and detailed 2HDM scenarios, analyzing their production, decay modes, and experimental signatures at the LHC.

Findings

Distortions in Higgs transverse momentum distributions could indicate new scalars.

Predicted multi-lepton and Z+jets+missing-energy events from scalar production.

Detailed spectra and decay modes for extra scalars in 2HDM models.

Abstract

In this study we consider an effective model by introducing two hypothetical real scalars, $H$ and $\chi$ - a dark matter candidate, where the masses of these scalars are $2 m_h < m_H < 2 m_t$ and $m_\chi \approx m_h/2$ with $m_h$ and $m_t$ being the Standard Model Higgs boson and top quark masses respectively. A distortion in the transverse momentum distributions of $h$ in the intermediate region of the spectrum through the processes $p p \to H \to h\chi\chi$ could be observed in this model. An additional scalar, $S$, has been postulated to explain large $H \to h\chi\chi$ branching ratios, assuming $m_h \lesssim m_S \lesssim m_H-m_h$ and $m_S > 2 m_\chi$. Furthermore, a scenario of a two Higgs doublet model (2HDM) is introduced and a detailed proposal at the present energies of the Large Hadron Collider to study the extra CP-even ($h, H$), CP-odd ($A$) and charged ($H^\pm$) scalars has been pursued. With possible phenomenological implications, all possible spectra and decay modes for these scalars are discussed. Based on the mass spectrum of $H, A$ and $H^\pm$, the production of multi-leptons and $Z$+jets+missing-energy events are predicted. A specific, Type-II 2HDM model is discussed in detail.