Updated Next-to-Next-to-Leading-Order QCD Predictions for the Weak Radiative B-Meson Decays.

Area of Science:

• Particle Physics
• High Energy Physics
• Flavor Physics

Background:

• Weak radiative decays of B mesons are crucial for constraining physics beyond the Standard Model.
• Accurate Standard Model predictions for inclusive branching ratios are essential for these constraints.

Purpose of the Study:

• To update Standard Model predictions for inclusive branching ratios of weak radiative B meson decays.
• To incorporate recent perturbative and nonperturbative corrections.
• To derive new bounds on new physics parameters, such as the charged Higgs boson mass.

Main Methods:

• Incorporation of O(α_{s}^{2}) and lower-order perturbative corrections.
• Inclusion of updated nonperturbative effect estimates.
• Calculation of branching ratios for radiative B meson decays (B_{sγ}, B_{dγ}) and their ratio to semileptonic decays (R_{γ}).

Main Results:

• Updated branching ratios: B_{sγ}=(3.36±0.23)×10^{-4} and B_{dγ}=(1.73_{-0.22}^{+0.12})×10^{-5} for E_{γ}>1.6 GeV.
• Ratio of radiative to semileptonic decays: R_{γ}=(3.31±0.22)×10^{-3}.
• New lower bound on the charged Higgs boson mass: M_{H^{±}}>480 GeV at 95% C.L. from B_{sγ} in the Two-Higgs-Doublet Model II.

Conclusions:

• The updated predictions for weak radiative B meson decays are consistent with current experimental measurements.
• These results provide stringent constraints on extensions of the Standard Model, particularly the Two-Higgs-Doublet Model II.