The shape function in field theory
arXiv:hep-ph/0009214 · doi:10.1016/S0920-5632(01)01165-3
Abstract
The shape function describes (non-perturbative) Fermi motion effects in semi-inclusive heavy flavour decay. Its renormalization properties are substantially dependent on the kind of ultraviolet regulator used. For example, the double logarithm that appears at one loop is larger by a factor 2 in dimensional regularization than in lattice regularization. We show that factorization of long-distance effects inside the shape function is achieved with any regulator considered.
Latex, 7 pages, 2 postscript figures, invited talk at the QCD 00 Euroconference, Montpellier, 6-13 July 2000