Testing Higgs boson scenarios in the phenomenological NMSSM

There could be another scalar in nature quasi-degenerate with the observed one (h${}_{125}$). This is possible in models such as the Next-to-Minimal Supersymmetric Standard Model (NMSSM). The scenario(s) with a single Higgs boson can be compared to that with multiple ones, all near 125 GeV. In order to assess the extent to which the current set of collider, cold dark matter relic density and direct detection limits are capable of discriminating these scenarios, we perform, for the first-time, global fits of a weak-scale phenomenological NMSSM with 26 free parameters using the nested sampling implementation in PolyChord, a next-generation tool for Bayesian inference. The analyses indicate that the data used shows a moderate tendency for supporting the scenario with an additional scalar much lighter than h${}_{125}$ with mass distribution centred below the W-boson mass. More stringent constraints are, however, needed for decisive inference regarding an additional Higgs boson with mass much less than or near 125 GeV.