The Q_{1,2}-Q_7 interference contributions to b -> s gamma at O(alpha_s^2) for the physical value of m_c

• Published in: arXiv.org 2023-12
• Main Authors: Czaja, M, Czakon, M, Huber, T, Misiak, M, Niggetiedt, M, Rehman, A, Schönwald, K, Steinhauser, M
• Format: Article
• Language: English
• Subjects: Dipoles; Gamma emission; Interference
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2309.14707

The B -> X_s gamma branching ratio is currently measured with around 5% accuracy. Further improvement is expected from Belle II. To match such a precision on the theoretical side, evaluation of O(alpha_s^2) corrections to the partonic decay b -> X_s^part gamma are necessary, which includes the b -> s gamma, b -> s g gamma, b -> s g g gamma, b -> s qbar q gamma decay channels. Here, we evaluate the unrenormalized contribution to b -> s gamma that stems from the interference of the photonic dipole operator Q_7 and the current-current operators Q_1 and Q_2. Our results, obtained in the cut propagator approach at the 4-loop level, agree with those found in parallel by Fael et al. who have applied the amplitude approach at the 3-loop level. Partial results for the same quantities recently determined by Greub et al. agree with our findings, too.