NNLO QCD counterterm contributions to B¯→Xsγ for the physical value of mc

Abstract One of the most important O ( α s 2 ) corrections to the B ¯ → X s γ branching ratio originates from interference of contributions from the current–current and photonic dipole operators. Its value has been estimated using an interpolation in the charm quark mass between the known results at m c = 0 and for m c ≫ 1 2 m b . An explicit calculation for the physical value of m c is necessary to remove the associated uncertainty. In the present work, we evaluate all the ultraviolet counterterm contributions that are relevant for this purpose.