750 GeV Resonance in the Gauged $U(1{)}^{\prime }$-Extended MSSM

Abstract

Recently the ATLAS and CMS collaborations at the LHC announced their observation of a potential 750 GeV di-photon resonance, after analyzing the $\sqrt{s}=13$ TeV LHC data. This observation has significant implications for low-energy supersymmetry. Beyond the MSSM and the NMSSM, we study the MSSM-extensions with an extra $U(1{)}^{\prime }$ gauge symmetry. The anomaly cancellation and the spontaneous breaking of the non-decoupled $U(1{)}^{\prime }$ generically require introducing vector-like supermultiplets (both colored and color-neutral ones) and singlet supermultiplets, respectively. We illustrate that the potential 750 GeV resonance ($Y$) can be accommodated in various mechanisms, as a singlet-like scalar or pseudoscalar. Three benchmark scenarios are presented: (1) vector-like quarks (VLQ) mediated $pp\to Y\to \gamma \gamma$; (2) scalar VLQ mediated $pp\to Y\to \gamma \gamma$; (3) heavy scalar (pseudo-scalar) $H/A$ associated production $pp\to H^{\ast }/A^{\ast }\to YH/h$. Additionally, we notice that the $Z^{\prime }$-mediated vector boson fusion production and $Z^{\prime }$-associated production $pp\to Yq{q}^{\prime }$, if yielding a signal rate of the observed level, might have been excluded by the searches for $Z^{\prime }$ via Drell-Yan process at the LHC.

Comments: v3, figure update with corresponding modification in discussion, version accepted by PLB