Corrections to $R_D$ and $R_{D^{\ast }}$ in the BLMSSM

Abstract

The deviation of the measurement of $R_D$ ($R_{D^{\ast }}$) from the Standard Model (SM) expectation is $2.3\sigma$ ($3.1\sigma$). $R_D$ ($R_{D^{\ast }}$) is the ratio of the branching fraction of $\overline{B}\to D\tau {\overline{\nu }}_{\tau }$ ($\overline{B}\to D^{\ast }\tau {\overline{\nu }}_{\tau }$) to that of $\overline{B}\to Dl{\overline{\nu }}_l$ ($\overline{B}\to D^{\ast }l{\overline{\nu }}_l$), where $l=e$ or $\mu$. This anomaly may imply the existence of new physics (NP). In this paper, we restudy this problem in the supersymmetric extension of the Standard Model with local gauged baryon and lepton numbers (BLMSSM), and give one-loop corrections to $R_D$ ($R_{D^{\ast }}$).