Rare top quark decays in the minimal R-symmetric supersymmetric standard model

Abstract

The one-loop contributions to the flavor-changing neutral current decays of the top quark into a light quark and a gauge boson or Higgs boson, namely $t\to qV,qh$, with $q$ being $u$ or $c$, and $V$ being $\gamma$, $g$, or $Z$, are analyzed in this study within the framework of the minimal R-symmetric supersymmetric standard model. The charginos in this model have been separated into two sets, i.e., $\chi$-chargino and $\rho$-chargino. The numerical results reveal that gluino or $\rho$-chargino predominantly dictate the predictions for BR($t\to qV,qh$), while the impact of neutralino or $\chi$-chargino contributions is insignificant. By incorporating the constraints imposed by the squark mixing parameters from $\bar{B}\to X_s\gamma$ and $B_{d,s}^0\to {\mu }^{+}{\mu }^{-}$, the theoretical predictions for BR($t\to qg$) can be significantly augmented to approximately $\mathcal{O}(10^{-5}-10^{-6})$. On the other hand, the values of BR($t\to q\gamma ,qZ,qh$) are predicted to be at least four orders of magnitude below the current experimental limits.

26 pages,8 figures