Deciphering the Long-Distance Penguin Contribution to B[over ¯]_{d,s}→γγ Decays

Area of Science:

• Particle Physics
• High Energy Physics
• Quantum Chromodynamics

Background:

• B-meson decays are crucial for testing the Standard Model.
• Understanding radiative decays requires precise theoretical calculations.
• Long-distance effects in B-meson decays are complex and challenging to compute.

Purpose of the Study:

• To compute the long-distance penguin contribution to double radiative B-meson decays.
• To investigate the role of up-quark and charm-quark loops in these decays.
• To assess the impact of these contributions on B meson decay observables as probes of new physics.

Main Methods:

• Application of the perturbative factorization theorem.
• Calculation of penguin amplitudes involving quark loops.
• Analysis of soft-gluon radiation effects.

Main Results:

• The first-ever computation of the long-distance penguin contribution to double radiative B-meson decays.
• Identification of the light up-quark loop as the dominant source of the penguin amplitude.
• Demonstration of a substantial cancellation of known factorizable power corrections due to the up-quark penguin contribution.

Conclusions:

• The calculated long-distance effects significantly impact B meson decay predictions.
• B_{d,s}→γγ decays are established as sensitive probes for physics beyond the Standard Model.
• The findings necessitate re-evaluation of theoretical predictions and experimental searches for new physics.