New physics in $b\rightarrow se^+e^-$: A model independent analysis

TL;DR

This paper conducts a model-independent analysis of potential new physics exclusively in the $b o s e^+ e^-$ decay channel, exploring various operator structures to explain lepton universality violation observed in $R_K/R_{K^*}$.

Contribution

It systematically evaluates all possible effective operators in $b o s e^+ e^-$ decay and identifies which can explain experimental anomalies, highlighting the discriminative power of the $P_1$ observable.

Findings

Vector/axial-vector operators can explain $R_K/R_{K^*}$ anomalies.

Scalar/pseudoscalar and tensor operators cannot account for the data.

The $P_1$ observable effectively discriminates between different new physics scenarios.

Abstract

The lepton universality violating flavor ratios $R_K/R_{K^*}$ indicate new physics either in $b \to s \mu^+ \mu^-$ or in $b \to s e^+ e^-$ or in both. If the new physics is only $b \to s e^+ e^-$ transition, the corresponding new physics operators, in principle, can have any Lorentz structure. In this work, we perform a model independent analysis of new physics only in $b \to se^+e^-$ decay by considering effective operators either one at a time or two similar operators at a time. We include all the measurements in $b\rightarrow se^+e^-$ sector along with $R_K/R_{K^*}$ in our analysis. We show that various new physics scenarios with vector/axial-vector operators can account for $R_K/R_{K^*}$ data but those with scalar/pseudoscalar operators and with tensor operators can not. We also show that the azimuthal angular observable $P_1$ in $B \to K^* e^+ e^-$ decay is most suited to discriminate between the different allowed solutions.