LHC phenomenology of light pseudoscalars in the NMSSM

TL;DR

This paper explores the potential for discovering light pseudoscalar particles in the NMSSM at the LHC, highlighting unique decay channels that could reveal new physics beyond the Standard Model.

Contribution

It demonstrates the feasibility of detecting light pseudoscalars through scalar decays into pseudoscalar pairs or Z bosons in the NMSSM, emphasizing novel search strategies.

Findings

Heavier scalars decaying to pseudoscalars or Z bosons can lead to discovery.

Light pseudoscalars may be lighter than the Higgs without conflicting with data.

Decay channels into pseudoscalar pairs could be the only discovery mode for certain scalars.

Abstract

After the discovery of the 125 GeV Higgs boson, the Next-to-Minimal Supersymmetric Standard Model (NMSSM) has become more interesting as a model for new physics since new tree-level contributions to the Higgs mass makes it easier to accommodate the relatively high measured value, as compared to the MSSM. One very distinctive feature of the NMSSM is the possible existence of a light singlet-like pseudoscalar. As this pseudoscalar may be lighter than the discovered Higgs boson without conflict with data, it may lead to LHC signatures rather different to what is usually searched for in terms of new physics. In these proceedings we will discuss studies concerning the discoverability of such light pseudoscalars. It is demonstrated that heavier scalars decaying to pairs of pseudoscalars or pseudoscalars and Z bosons may lead to discovery in a large part of the parameter space. This is especially important for the non-SM like of the two lightest scalars, as it may have an almost 100% branching ratio for decay into pairs of pseudoscalars. In such a case the discussed channels might be our only means of discovery, also for the scalar.