Constraints on the charged scalar effects using the forward-backward asymmetry on $B\to D^{(*)}\tau\bar{\nu_{\tau}}$

TL;DR

This paper proposes a method using branching ratios and forward-backward asymmetries in B meson decays to D(*) tau neutrino final states to constrain charged scalar effects like the charged Higgs, aiding in distinguishing Standard Model from new physics.

Contribution

It introduces a novel approach utilizing forward-backward asymmetries in specific tau decay channels to probe charged scalar contributions in B decays.

Findings

Forward-backward asymmetries effectively discriminate between Standard Model and new physics scenarios.

The method enhances sensitivity to charged Higgs effects in B decay processes.

Ratios of branching fractions combined with asymmetries provide robust constraints on charged scalar models.

Abstract

The decay modes $\bar{B}\to D^{(*)}\tau\bar{\nu}_{\tau}$ are sensitive to charged scalar effects, such as the charged Higgs effects. In this paper we suggest a method to determine their effects by using the ratio of branching fractions and forward-backward asymmetries. In particular, forward-backward asymmetries on $\bar{B}\to D^{(*)}\tau(\to \pi\nu_{\tau})\bar{\nu}_{\tau}$, $\bar{B}\to D^{(*)}\tau(\to \rho\nu_{\tau})\bar{\nu}_{\tau}$, and $\bar{B}\to D^{(*)}\tau(\to a_1\nu_{\tau})\bar{\nu}_{\tau}$ play an important role, which discriminate the Standard Model from other New Physics scenarios.