Top quark decays with flavor violation in the B-LSSM

TL;DR

This paper investigates rare top quark decays involving flavor violation within the B-LSSM, predicting branching ratios that could be detectable and differ from the Standard Model, influenced by new gauge interactions.

Contribution

It provides the first detailed analysis of top quark flavor-violating decays in the B-LSSM, including numerical predictions under experimental constraints.

Findings

Predicted branching ratios are around 10^{-7} to 10^{-6} for certain decays.

New gauge couplings significantly influence decay probabilities.

Results suggest potential observability at future colliders.

Abstract

The decays of top quark $t\rightarrow c\gamma,\;t\rightarrow cg,\;t\rightarrow cZ,\;t\rightarrow ch$ are extremely rare processes in the standard model (SM). The predictions on the corresponding branching ratios in the SM are too small to be detected in the future, hence any measurable signal for the processes at the LHC is a smoking gun for new physics. In the extension of minimal supersymmetric standard model with an additional local $U(1)_{B-L}$ gauge symmetry (B-LSSM), new gauge interaction and new flavor changing interaction affect the theoretical evaluations on corresponding branching ratios of those processes. In this work, we analyze those processes in the B-LSSM, under a minimal flavor violating assumption for the soft breaking terms. Considering the constraints from updated experimental data, the numerical results imply $Br(t\rightarrow c\gamma)\sim5\times10^{-7}$, $Br(t\rightarrow cg)\sim2\times10^{-6}$, $Br(t\rightarrow cZ)\sim4\times10^{-7}$ and $Br(t\rightarrow ch)\sim3\times10^{-9}$ in our chosen parameter space. Simultaneously, new gauge coupling constants $g_{_B},\;g_{_{YB}}$ in the B-LSSM can also affect the numerical results of $Br(t\rightarrow c\gamma,\;cg,\;cZ,\;ch)$.