Enhanced $B_s$--${\bar{B}}_s$ lifetime difference and anomalous like-sign dimuon charge asymmetry from new physics in $B_s\to {\tau }^{+}{\tau }^{-}$

Abstract

New physics models that increase the decay rate of $B_s\to {\tau }^{+}{\tau }^{-}$ contribute to the absorptive part of $B_s$--${\bar{B}}_s$ mixing, and may enhance $\Delta {\Gamma }_s$ all the way up to its current experimental bound. In particular, the model with a scalar leptoquark can lead to a significant violation of the expectation $\Delta {\Gamma }_s\le \Delta {\Gamma }_s$ (SM). It can even allow regions in the $\Delta {\Gamma }_s$-${\beta }_s$ parameter space that are close to the best fit obtained by CDF and D\{O} through $B_s\to J/\psi \varphi$. In addition, it can help explain the anomalous like-sign dimuon charge asymmetry observed recently by DØ. A measurement of $BR(B_s\to {\tau }^{+}{\tau }^{-})$ is thus crucial for a better understanding of new physics involved in $B_s$--${\bar{B}}_s$ mixing.

Comments: v3: 5 pages, 3 eps figures, Version to be published in Phys. Rev. D, Rapid Communications