A light NMSSM pseudoscalar Higgs boson at the LHC Run 2

Abstract

We revisit the light pseudoscalar $A_1$ in the Next-to-Minimal Supersymmetric Standard Model (NMSSM) with partial universality at some high unification scale in order to delineate the parameter space regions consistent with up-to-date theoretical and experimental constraints and examine to what extent this state can be probed by the Large Hadron Collider (LHC) during Run 2. We find that it can be accessible through a variety of signatures proceeding via $A_1\to \tau^+\tau^-$ and/or $b\bar b$, the former assuming hadronic decays and the latter two $b$-tags within a fat jet or two separate slim ones. Herein, the light pseudoscalar state is produced from a heavy Higgs boson decay in either pairs or singly in association with a $Z$ boson (in turn decaying into electrons/muons).