Four-Loop Anomalous Dimensions for Radiative Flavour-Changing Decays
Abstract
We evaluate the complete four-loop anomalous dimension matrix that is necessary for determining the effective flavour-changing neutral current couplings qbar-q'-gamma and qbar-q'-g at the next-to-next-to-leading order in QCD. The resulting O(alphas2(mub)) correction to the B -> Xs gamma branching ratio amounts to around -2.9% for mub = 5 GeV, and -4.4% for mub = 2.5 GeV
0
Turn this paper into a full lesson
ArcXiv compiles a staged curriculum from this paper: 8-12 lessons across beginner → advanced, synthesised section guides, visuals, flashcards, a quiz, exercises, and on-demand deep dives per section. Grounded in the abstract, never invented.