Renormalization of the shape function

by Ugo AGLIETTI (TH Division, CERN)

Friday 22 Oct 1999, 14:00 → 14:15 Europe/Zurich

TH Auditorium (CERN)

The shape function f(k+) is introduced to describe Fermi motion effects in inclusive semileptonic b Æ u decays, such as for example B Æ X_u ln. This function is defined in the framework of the low-energy effective theory (HQET & LEET) and has peculiar renormalization properties. The understanding of the latter is essential for connecting the effective theory shape function to the original, high-energy theory, observable. In the seminar an introduction will be given to the basics and the phenomenology of the shape function, together with a discussion of the renormalization in various regularisation schemes and of the matching onto full QCD (coefficient function).