New Physics in b -> s mu+ mu-: CP-Violating Observables

TL;DR

This paper investigates how different types of new physics operators affect CP-violating observables in b -> s mu+ mu- decays, finding that vector-axial vector operators predominantly influence these CP asymmetries.

Contribution

It provides a comprehensive analysis of the impact of various Lorentz-structured new physics operators on CP violation in b -> s mu+ mu- transitions, highlighting the dominance of VA operators.

Findings

CP-violating observables are mainly sensitive to VA operators.

Future measurements can identify VA new physics unambiguously.

Scalar, pseudoscalar, and tensor operators have limited impact on CP asymmetries.

Abstract

We perform a comprehensive study of the impact of new-physics operators with different Lorentz structures on CP-violating observables involving the b -> s mu+ mu- transition. We examine the effects of new vector-axial vector (VA), scalar-pseudoscalar (SP) and tensor (T) interactions on the CP asymmetries in the branching ratios and forward-backward asymmetries of Bs -> mu mu, B -> Xs mu mu, Bs -> mu mu gamma, B -> K mu mu, and B -> K* mu mu. In B -> K* mu mu, we also explore the direct CP asymmetries in the longitudinal polarization fraction f_L and the angular asymmetries A_T^{(2)} and A_{LT}, as well as the triple-product CP asymmetries A_T^{(im)} and A^{(im)}_{LT}. We find that, in almost all cases, the CP-violating observables are sensitive only to new physics which involves VA operators. The VA new physics may therefore be unambiguously identified by a combined analysis of future measurements of these CP-violating observables.