Supersymmetric contributions to ${\bar{B}}_s\to \varphi {\pi }^0$ and ${\bar{B}}_s\to \varphi {\rho }^0$ decays in SCET

Abstract

We study the decay modes ${\bar{B}}_s\to \varphi {\pi }^0$ and ${\bar{B}}_s\to \varphi {\rho }^0$ using Soft Collinear Effective Theory. Within Standard Model and including the error due to the SU(3) breaking effect in the SCET parameters we find that BR ${\bar{B}}_s\to \varphi {\pi }^0=7_{-1-2}^{+1+2}\times 10^{-8}$ and BR ${\bar{B}}_s\to \varphi {\pi }^0=9_{-1-4}^{+1+3}\times 10^{-8}$ corresponding to solution 1 and solution 2 of the SCET parameters respectively.For the decay mode ${\bar{B}}_s\to \varphi {\rho }^0$, we find that BR ${\bar{B}}_s\to \varphi {\rho }^0=20.2_{-1-12}^{+1+9}\times 10^{-8}$ and BR ${\bar{B}}_s\to \varphi {\rho }^0=34.0_{-1.5-22}^{+1.5+15}\times 10^{-8}$ corresponding to solution 1 and solution 2 of the SCET parameters respectively. We extend our study to include supersymmetric models with non-universal A-terms where the dominant contributions arise from diagrams mediated by gluino and chargino exchanges. We show that gluino contributions can not lead to an enhancement of the branching ratios of ${\bar{B}}_s\to \varphi {\pi }^0$ and ${\bar{B}}_s\to \varphi {\rho }^0$. In addition, we show that SUSY contributions mediated by chargino exchange can enhance the branching ratio of ${\bar{B}}_s\to \varphi {\pi }^0$ by about 14% with respect to the SM prediction. For the branching ratio of ${\bar{B}}_s\to \varphi {\rho }^0$, we find that SUSY contributions can enhance its value by about 1% with respect to the SM prediction.

Comments: 25 pages,5 figures, version accepted for publication