Effect of the Charged Higgs Bosons in the Radiative Leptonic Decays of $B^-$ and $D^-$ Mesons

TL;DR

This paper investigates how charged Higgs bosons influence the radiative leptonic decays of B and D mesons within the Standard Model and two-Higgs-doublet models, highlighting potential observable effects in specific decay channels.

Contribution

It provides a detailed analysis of charged Higgs effects on meson decays using factorization and relativistic potential models, including the first estimate of a 13% contribution in a key decay mode.

Findings

The decay mode B→γτν_τ is sensitive to charged Higgs effects.

Charged Higgs contributions can reach approximately 13% in certain decay channels.

The study incorporates order O(Λ_QCD/m_Q) corrections in the analysis.

Abstract

In this work, we study the radiative leptonic decays of $B^-$ and $D^-$ mesons in the standard model and the two-Higgs-doublet-model type II. The results are obtained using the factorization procedure, and the contribution of the order $O(\Lambda _{\rm QCD}\left/m_Q\right.)$ is included. The numerical results are calculated using the wave-function obtained in relativistic potential model. As a result, the decay mode $B\to \gamma \tau \nu_{\tau}$ is found to be sensitive to the effect of the charged Higgs boson. Using the constraint on the free parameters of the two Higgs doublet model given in previous works, we find the contribution of the charged Higgs boson in the decay mode $B\to \gamma \tau \nu_{\tau}$ can be as large as about $13\%$.