# Probing new physics in $B_s \to (K,K^*)\tau \nu$ and $B \to \pi \tau \nu$ decays

## TL;DR

This paper investigates potential new physics effects in specific B meson decays involving tau leptons, using an effective field theory approach and assuming similar new physics patterns across related decay channels.

## Contribution

It provides predictions for various observables in B decays with tau leptons under new physics scenarios, extending the standard model analysis with vector-type couplings.

## Key findings

- Predicted branching ratios and asymmetries in B decays with tau leptons.
- Identified potential signatures of new physics in decay observables.
- Compared standard model and new physics predictions for key decay parameters.

## Abstract

Motivated by the anomalies present in $b \to u$ and $b \to c$ semileptonic decays, we study the corresponding $B_s \to (K,K^*) \tau \nu$ and $B \to \pi \tau \nu$ decays within an effective field theory formalism. Our analysis is based on a strict model dependent assumption, i.e., we assume that $b \to u$ and $b \to c$ transition decays exhibit similar new physics pattern. We give prediction of various observables such as the branching fraction, ratio of branching ratio, lepton side forward-backward asymmetry, longitudinal polarization fraction of the charged lepton and convexity parameter in the standard model and in the presence of vector type new physics couplings.