Probing the two light Higgs scenario in the NMSSM with a low-mass pseudoscalar

TL;DR

This paper proposes a collider search strategy for a two-light-Higgs scenario in the NMSSM, focusing on multi-lepton final states from light pseudoscalar decays, which could reveal new Higgs sector physics at the LHC.

Contribution

It introduces a novel collider search method for light pseudoscalars in the NMSSM using multi-lepton signals, highlighting its potential to complement existing Higgs searches.

Findings

Multi-lepton final states can effectively probe the light pseudoscalar in NMSSM.

LHC at 8 TeV with 25 fb⁻¹ can test this scenario and estimate pseudoscalar and scalar masses.

Dedicated searches can improve understanding of the NMSSM Higgs sector.

Abstract

In this article we propose a simultaneous collider search strategy for a pair of scalar bosons in the NMSSM through the decays of a very light pseudoscalar. The massive scalar has a mass around 126 GeV while the lighter one can have a mass in the vicinity of 98 GeV (thus explaining an apparent LEP excess) or be much lighter. The successive decay of this scalar pair into two light pseudoscalars, followed by leptonic pseudoscalar decays, produces clean multi-lepton final states with small or no missing energy. Furthermore, this analysis offers an alternate leptonic probe for the 126 GeV scalar that can be comparable with the ZZ* search channel. We emphasize that a dedicated experimental search for multi-lepton final states can be an useful probe for this scenario and, in general, for the NMSSM Higgs sector. We illustrate our analysis with two representative benchmark points and show how the LHC configuration with 8 TeV center-of-mass energy and 25 inverse femtobarns of integrated luminosity can start testing this scenario, providing a good determination of the light pseudoscalar mass and a relatively good estimation of the lightest scalar mass.