Results of the O ( α s ) two - loop virtual corrections to B → X s l + l − in the standard model
نویسنده
چکیده
We present the results of the O(αs) two-loop virtual corrections to the differential decay width dΓ(B → Xsll)/dŝ, where ŝ is the invariant mass squared of the lepton pair, normalized to m b . Those contributions from gluon bremsstrahlung which are needed to cancel infrared and collinear singularities are also included. Our calculation is restricted to the range 0.05 ≤ ŝ ≤ 0.25 where the effects from resonances are small. The new contributions drastically reduce the renormalization scale dependence of existing results for dΓ(B → Xsll)/dŝ. The renormalization scale uncertainty of the corresponding branching ratio (restricted to 0.05 ≤ ŝ ≤ 0.25) gets reduced from ∼ ±13% to ∼ ±6.5%.
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