On NMSSM Higgs Search Strategies at the LHC and the Mono-Higgs Signature in Particular

We study the collider phenomenology of the extended Higgs sector of the Next-to-Minimal Supersymmetric Standard Model (NMSSM). The region of NMSSM parameter space favored by a 125\,GeV SM-like Higgs and naturalness generically features a light Higgs and neutralino spectrum as well as a large $\mathcal{O}(1)$ coupling between the Higgs doublets and the NMSSM singlet fields. In such regimes, the heavier Higgs bosons can decay dominantly into lighter Higgs bosons and neutralinos. We study the prospects of observing such decays at the 13\,TeV LHC, focusing on mono-Higgs signatures as probes of such regions of parameter space. We present results in a model-independent framework as well as in the NMSSM. In the NMSSM, we find that the mono-Higgs channel can probe TeV scale Higgs bosons and has sensitivity even in the low tan$\beta$, large $m_A$ regime that is difficult to probe in the MSSM. Unlike for many conventional Higgs searches, the reach of the mono-Higgs channel will improve significantly with the increased luminosity expected to be collected at the LHC in the ongoing and upcoming runs.