The impact of additional scalar bosons at the LHC

Abstract

In this study we consider an effective model by introducing two hypothetical real scalars, $H$ and $\ddot{I}‡$ - a dark matter candidate, where the masses of these scalars are $2m_h<m_H<2m_t$ and $m_{\ddot{I}}‡\approx m_h/2$ 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 $pp\to H\to h\ddot{I}‡\ddot{I}‡$ could be observed in this model. An additional scalar, $S$, has been postulated to explain large $H\to h\ddot{I}‡\ddot{I}‡$ branching ratios, assuming $m_h\lesssim m_S\lesssim m_H-m_h$ and $m_S>2m_{\ddot{I}}‡$. 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.

Submitted to the book of proceedings of the High Energy Particle Physics workshop, February 8th-10th 2016, iThemba LABS, South Africa