Enhanced CP asymmetries in $B\to K{\mu }^{+}{\mu }^{-}$

Abstract

We show that the current values of $R_K^{\exp }$ and $R_{K^{\ast }}^{\exp }$ can be accommodated by allowing a nonzero New Physics coupling $\delta C_9^{\mu \mu }$ to be complex, both in the scenario in which only $\delta C_9^{\mu \mu }$ is affected, and in the scenario with complex $\delta C_{9,10}^{\mu \mu }$ satisfying $\delta C_9^{\mu \mu }=-\delta C_{10}^{\mu \mu }$. A presence of the weak CP-violating phase can then be tested by measuring the CP-asymmetry, ${\mathcal{A}}_{\mathrm{CP}}$. We show that this asymmetry is enhanced around the peak of each $c\bar{c}$-resonance, and in fact more pronounced in the close vicinity of $J/\psi$ and $\psi (2S)$. Therefore, measuring ${\mathcal{A}}_{\mathrm{CP}}$ before and after the resonances' peak could be revelatory of the CP-violation that originates from beyond the Standard Model, or to be a significant constrain when building a realistic scenario of New Physics.

Comments: Added missing references