Testing leptoquark models in $\bar B \to D^{(*)} \tau \bar\nu$

TL;DR

This paper investigates how leptoquark models could explain anomalies in B meson decays involving tau leptons, constraining model parameters with recent experimental data and exploring future observable correlations.

Contribution

It provides new constraints on leptoquark couplings using recent measurements of B decay ratios and compares these with other experimental bounds.

Findings

Constraints on leptoquark couplings derived from $R(D^{(*)})$ measurements.

Comparison of leptoquark constraints with bounds from $BR(B o X_s u ar u)$.

Predictions of observable correlations to distinguish different New Physics scenarios.

Abstract

We study potential New Physics effects in the $\bar B \to D^{(*)} \tau \bar\nu$ decays. As a particular example of New Physics models we consider the class of leptoquark models and put the constraints on the leptoquark couplings using the recently measured ratios $R(D^{(*)})=BR(\bar B \to D^{(*)} \tau \bar\nu)/BR(\bar B \to D^{(*)} \mu \bar\nu)$. For consistency, some of the constraints are compared with the ones coming from the current experimental bound on $BR(B \to X_s \nu \bar\nu)$. In order to discriminate various New Physics scenarios, we examine the correlations between different observables that can be measured in future.