Effects of a charged Higgs boson in $B \rightarrow D^{(*)} \tau \nu$ decays

TL;DR

This paper examines how a charged Higgs boson could influence B meson decays to D(*) tau nu, exploring potential signs of new physics in recent experimental anomalies within two-Higgs-doublet models.

Contribution

It analyzes the impact of charged Higgs bosons on B decay processes and discusses constraints from other meson decays in the context of two-Higgs-doublet models.

Findings

Charged Higgs contributions can significantly affect B decay rates.

Current experimental excesses may be explained by charged Higgs effects.

Constraints from other meson decays limit the parameter space for new physics.

Abstract

In this talk I consider the current status of $B \rightarrow D^{(*)} \tau \nu$ decays in the context of two-Higgs-doublet models. The BaBar collaboration has reported an excess in semileptonic $b \rightarrow c \tau \nu$ transitions that has gathered recent interest as a possible signature of new physics. The sensitivity of these decays to tree-level charged Higgs boson contributions is discussed, taking into account the constraints from other semileptonic and leptonic meson decays in which the charged Higgs would enter at the same level.