Yaşar Hiçyılmaz
Speaker affiliation: 
University of Southampton
Tuesday, October 22, 2019 - 12:30
CLS Lecture C (46/2005)
Charged Higgs in MSSM and Beyond

Charged Higgs boson ($ H^{\pm} $), which exists in many Supersymmetric (SUSY)/Non-SUSY models, is one of the most important evidences for new physics beyond the Standard Model. This talk is about a numerical study over the constrained Minimal Supersymmetric Standard Model (CMSSM), next-to-MSSM (NMSSM) and U(1) extended MSSM (UMSSM). In this work, we investigate the allowed mass ranges of the charged Higgs boson and its dominant decay patterns, which might come into prominence in the near future collider experiments. We present the results for MSSM as a basis to compare the results for the extended models. Despite the narrow mass range in MSSM as $2 \lesssim m_{H^{\pm}} \lesssim 3$ TeV, much wider mass range is allowed as $0.5(1) \lesssim m_{H^{\pm}} \lesssim 17$ TeV in UMSSM (NMSSM). Such wide mass ranges for the charged Higgs boson can allow some decay modes, which might not be possible to realize in MSSM. We find that the dominant decay channel is mostly $H^{\pm}\rightarrow tb$ such that ${\rm BR}(H^{\pm}\rightarrow tb) \sim 80\%$. While this mode remains dominant over the whole allowed parameter space of MSSM, we realize some regions in the NMSSM and UMSSM parameter regions, in which ${\rm BR}(H^{\pm}\rightarrow tb) \lesssim 10\%$. in this context, the decay patterns can play a role to distinguish the SUSY models. In addition to the $tb$ decay mode, we find that the narrow mass scale in MSSM allows only the decay modes for the charged Higgs boson to $\tau\nu$ ($\sim 21\%$), and their supersymmetric partners $\tilde{\tau}\tilde{\nu}$ ($\sim 25\%$). On the other hand, it is possible to realize the mode in NMSSM and MSSM in which the charged Higgs boson decays into a chargino and neutralino pair up to about $25\%$. This decay mode can be distinguishing these models, since MSSM does not allow such modes anymore. It can also be probed in near future collider experiments through the missing energy and CP-violation measurements. Moreover, the chargino mass is realized as $m_{\tilde{\chi}_{1}^{\pm}} \gtrsim 1$ TeV in NMSSM and UMSSM, and these solutions will be likely tested soon in collider experiments through the chargino-neutralino production. Focusing on the chargino-neutralino decay mode, we also present tables which list the possible ranges for the charged Higgs production and its decay modes.