https://doi.org/10.1140/epjc/s10052-008-0623-5
Regular Article - Theoretical Physics
Towards B→Vγ decays at NNLO in SCET
1
Theory Group, Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22603, Hamburg, Germany
2
Institute for Theoretical Physics, Univ. Berne, Sidlerstr. 5, 3012, Bern, Switzerland
* e-mail: ahmed.ali@desy.de
Received:
1
October
2007
Revised:
15
April
2008
Published online:
20
May
2008
We compute NNLO (
(αs
2)) corrections to the hard-scattering kernels entering the QCD factorization formula for B→Vγ decays, where V is a light vector meson. We give complete NNLO results for the dipole operators Q7 and Q8, and partial results for Q1 valid in the large-β0 limit and neglecting the NNLO correction from hard-spectator scattering. Large perturbative logarithms in the hard-scattering kernels are identified and resummed using soft-collinear effective theory. We use our results to estimate the branching fractions for B→K*γ and Bs→φγ decays at NNLO and compare them with the current experimental data.
© Springer-Verlag , 2008
