# Weak Radiative Decays of the B Meson and Bounds on $M_{H^\pm}$ in the Two-Higgs-Doublet Model

## TL;DR

This paper updates the bounds on the charged Higgs boson mass in the Two-Higgs-Doublet Model based on recent Belle collaboration data on B-meson decays, highlighting the impact of experimental improvements and methodological choices.

## Contribution

It provides revised bounds on $M_{H^}$ in the Two-Higgs-Doublet Model using the latest experimental data and clarifies ambiguities related to photon energy cutoff choices.

## Key findings

- Lower bound on $M_{H^}$ is now 570-800 GeV at 95% C.L.
- Updated bounds are sensitive to the method of analysis and photon energy cutoff.
- The experimental branching ratio is below the Standard Model prediction but remains consistent.

## Abstract

In a recent publication [6], the Belle collaboration updated their analysis of the inclusive weak radiative B-meson decay, including the full dataset of (772 +_ 11) x 10^6 BBbar pairs. Their result for the branching ratio is now below the Standard Model prediction [7,8], though it remains consistent with it. However, bounds on the charged Higgs boson mass in the Two-Higgs-Doublet Model get affected in a significant manner. In the so-called Model-II, the 95% C.L. lower bound on $M_{H^\pm}$ is now in the 570-800 GeV range, depending quite sensitively on the method applied for its determination. Our present note is devoted to presenting and discussing the updated bounds, as well as to clarifying several ambiguities that one might encounter in evaluating them. One of such ambiguities stems from the photon energy cutoff choice, which deserves re-consideration in view of the improved experimental accuracy.