Investigating the potential of RτμK(∗)to probe lepton flavor universality violation

In this work we study the potential of the lepton flavor ratios R-K(tau mu)equivalent to Gamma(B -> K tau(+)tau(-))/Gamma(B -> K mu(+)mu(-)) and R-K & lowast;(tau mu)equivalent to Gamma(B -> K & lowast;tau(+)tau(-))/Gamma(B -> K-& lowast;mu(+)mu(-)) to probe lepton flavor universality (LFU) violation in tau-mu sector. We show that these ratios can deviate from their SM values even if the new physics couplings are universal in nature, i.e., having equal couplings to e, mu and tau leptons. Therefore in order to utilize these observables to probe LFU violation, we need to compare the allowed range of R-K(& lowast;)(tau mu) for class of solutions with only universal couplings to leptons and solutions having both universal and non-universal components. For the current b -> s & ell;& ell; (& ell;=e,mu) data, we find that these two class of solutions can be discriminated provided the measured value of R(K & lowast; )(tau mu)is greater than the SM prediction.

Automated summary

In this study, we investigate the potential of lepton flavor ratios to probe lepton flavor universality violation in the tau-mu sector. Our findings show that these ratios can deviate from their Standard Model values even when the new physics couplings are universal. Therefore, in order to detect lepton flavor universality violation, it is necessary to compare the range of these ratios for solutions with only universal couplings and solutions with both universal and non-universal components.