Four-loop anomalous dimensions for radiative flavour-changing decays
We evaluate the complete four-loop anomalous dimension matrix that is necessary for determining the effective flavour-changing neutral current couplings q′γ and q′g at the next-to-next-to-leading order in QCD. The resulting (αs2(μb)) correction to the Xsγ branching ratio amounts to around -2.9 for μ...
| Main Authors: | , , |
|---|---|
| Format: | Journal article |
| Language: | English |
| Published: |
2007
|