Year: 2026
Type: preprint
Abstract: We present a new and upgraded analysis of the inclusive weak radiative decay of the $B$ meson in the standard model and beyond. The ${\mathcal O}(α_s)$ perturbative corrections are included in a formally complete manner. At the order $α_s^2$, exact dependence on the charm quark mass is calculated for the dominant corrections, which removes a sizeable uncertainty that was present in all the previous analyses. The global normalization factor and many of the non-perturbative contributions are expressed in terms of the kinetic-scheme mass of the $b$-quark and the heavy-quark-expansion matrix elements. These parameters are adopted from the most recent semileptonic fits that include ${\mathcal O}(α_s^3)$ corrections and up-to-date experimental results. We find ${\mathcal B}_{sγ}^{\rm SM} = (3.54 \pm 0.14)\times 10^{-4}$ for the CP- and isospin-averaged branching ratio of the considered decay in the standard model, with a lower cut on the photon energy $E_γ> 1.6\,{\rm GeV}$. It agrees with the current experimental average ${\mathcal B}_{sγ}^{\rm exp} = (3.49 \pm 0.19)\times 10^{-4}$, which provides constraints on beyond standard model physics. In particular, we find $M_{H^\pm} > 670\,{\rm GeV}$ at $95\%\,{\rm C.L.}$ for the charged Higgs boson mass in the two-Higgs-doublet model~II.
Source: arXiv (Cornell University)
Institutions: University of Warsaw, A. Alikhanyan National Laboratory, Johannes Gutenberg University Mainz, Mainz Institute for Theoretical Physics, Karlsruhe Institute of Technology, RWTH Aachen University, University of Padua, Istituto Nazionale di Fisica Nucleare, Sezione di Padova, University of Siegen, University of Zurich, Paul Scherrer Institute, University of Bern, University of Alberta, European Organization for Nuclear Research
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Awards: G1227734240, TRR 257: Phänomenologische Elementarteilchenphysik nach der HiggsEntdeckung, G2124226988, G2301612669, G2645866196, EXC 2118: Precision Physics, Fundamental Interactions and Structure of Matter (PRISMA+), G6237201456, High-precision scattering amplitudes for the LHC and lepton colliders from automated NNLO calculations, G7581871610
OpenAlex ID: W7204868966