[Hybrid RBRC seminar] QED effects in exclusive B decays and light-cone distribution amplitudes

by Martin Beneke (Technical University of Munich)

Thursday 4 Apr 2024, 12:30 → 13:30 US/Eastern

2-160 ( https://bnl.zoomgov.com/j/1619458475?pwd=Z1VDdXVXcWF1eUhsRDZObVJnME4rUT09)

Abstract:
The exponentiation of soft photon radiation is a classic
result of QED, but for QED effects on objects with structure
a more general approach is required. In this seminar I
discuss how modern methods of effective field theory and
factorization (more familiar for the strong interaction)
result in a systematic treatment of QED effects in decays of
B mesons to a lepton pair, or a pair of light mesons,
including the summation of large logarithms.  On top of
adding precision, QED offers surprises: for B ->  mu mu,
the QED correction is enhanced in heavy-quark power counting,
and reveals that the process is no longer a pure annihilation
decay. The presence of QED also modifies the definition
and properties of light-cone distribution amplitudes of
light mesons and B mesons in an interesting way.