The Z+photon and diphoton decays of the Higgs boson as a joint probe of low energy SUSY models at LHC

TL;DR

This paper investigates the rare Higgs decay processes to Zγ and γγ in various low-energy SUSY models, analyzing their correlations and potential to distinguish models at the LHC and future colliders.

Contribution

It provides a comparative analysis of Zγ and γγ Higgs decay rates across multiple SUSY models, highlighting their correlations and experimental signatures.

Findings

In CMSSM, both rates are slightly suppressed compared to SM.

In MSSM, rates can be enhanced or suppressed, with possible enhancement factors of 1.2 and 2.

In NMSSM, the rates are strongly correlated and vary from 0.2 to 2.

Abstract

In light of recent remarkable progress in Higgs search at the LHC, we study the rare decay process $h \to Z\gamma$ and show its correlation with the decay $h \to \gamma\gamma$ in low energy SUSY models such as CMSSM, MSSM, NMSSM and nMSSM. Under various experimental constraints, we scan the parameter space of each model, and present in the allowed parameter space the SUSY predictions on the $Z\gamma$ and $\gamma\gamma$ signal rates in the Higgs production at the LHC and future e+e- linear colliders. We have following observations: (i) Compared with the SM prediction, the $Z\gamma$ and $\gamma\gamma$ signal rates in the CMSSM are both slightly suppressed; (ii) In the MSSM, both the $Z\gamma$ and $\gamma\gamma$ rates can be either enhanced or suppressed, and in optimal case, the enhancement factors can reach 1.2 and 2 respectively; (iii) In the NMSSM, the $Z\gamma$ and $\gamma\gamma$ signal rates normalized by their SM predictions are strongly correlated, and vary from 0.2 to 2; (iv) In the nMSSM, the $Z\gamma$ and $\gamma\gamma$ rates are greatly reduced. Since the correlation behavior between the Z\gamma signal and the \gamma\gamma signal is so model-dependent, it may be used to distinguish the models in future experiments.