CP violation in Charged Higgs Bosons decays $H^\pm \to W^\pm (\gamma, Z)$ in the Minimal Supersymmetric Standard Model (MSSM)

TL;DR

This paper investigates CP violation effects in charged Higgs boson decays within the MSSM, revealing potential large CP asymmetries and branching ratios that could be observable in experiments.

Contribution

It provides the first detailed analysis of CP violation in $H^ o W^ o V$ decays in the MSSM, including the impact of CP phases and experimental constraints.

Findings

Branching ratio of $H^ o W^Z$ can reach 10^{-3}.

CP phases can modify branching ratios by an order of magnitude.

CP asymmetry can be as large as 80%.

Abstract

One loop mediated charged Higgs bosons decays $H^\pm\to W^\pm V$, $V= Z, \gamma$ are studied in the Minimal Supersymmetric Standard Model (MSSM) with and without CP violating phases. We evaluate the MSSM contributions to these processes taking into account $B\to X_s\gamma$ constraint as well as experimental constraints on the MSSM parameters. In the MSSM, we found that in the intermediate range of $\tan\beta \la 10$ and for large A_t and large $\mu$, where the lightest top squark becomes very light and hence non-decoupled, the branching ratio of $H^\pm \to W^{\pm} Z$ can be of the order 10^{-3} while the branching ratio of $H^\pm \to W^{\pm} \gamma$ is of the order 10^{-5}. We found also that the CP violating phases of soft SUSY parameters can modify the branching ratio by about one order of magnitude. We also show that MSSM with CP violating phases lead to CP-violating asymmetry in the decays $H^+ \to W^+V$ and $H^- \to W^-V$. Such CP asymmetry can be rather large and can reach 80% in some region of parameter space.