On transverse asymmetries in B --> K* l+l-

TL;DR

This paper analyzes three transverse asymmetries in B --> K* l+l- decays, which are sensitive to new physics and can be measured through angular analysis, providing a tool to distinguish among different new physics scenarios.

Contribution

It introduces three specific asymmetries that are accessible experimentally, have reduced hadronic uncertainties, and can help identify new physics effects in B decays.

Findings

Asymmetries are accessible from angular analysis.

Asymmetries are insensitive to hadronic uncertainties.

Formulas apply to both massless and massive leptons.

Abstract

We discuss the three independent asymmetries, AT(2)(q2), AT(im)(q2) and AT(re)(q2), that one can build from the amplitudes A_perp(q2) and A_par(q2). These quantities are expected to be accessible from the new B-physics experiments, they are sensitive to the presence of new physics, and they are not significantly sensitive to hadronic uncertainties. Studying their low q2-dependence can be helpful in discerning among various possible new physics scenarios. All three asymmetries can be extracted from the full angular analysis of B-->K* l+l-. Our formulas apply to both the massless and the massive lepton case.