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

Author:

M. Czaja, M. Czakon, T. Huber, M. Misiak, M. Niggetiedt, A. Rehman, K. Schönwald, M. Steinhauser

Keyword:

High Energy Physics - Phenomenology, High Energy Physics - Phenomenology (hep-ph)

journal:

TTK-23-22, TTP23-038, P3H-23-063, ZU-TH 57/23, ALBERTA-THY-6-23, SI-HEP-2023-20, MPP-2023-190

date:

2023-09-25 16:00:00

Abstract

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.

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