Eur Phys J C (2004) 33: s324-s326
https://doi.org/10.1140/epjcd/s2003-03-219-9

PS02 Rare Decays

Non-valence Fock states in heavy-to-light form factors at large recoil

Newman Laboratory for Elementary-Particle Physics, Cornell University, Ithaca, NY 14853, USA

Received: 1 October 2003
Accepted: 9 October 2003
Published online: 22 October 2003

Abstract

We studied three-particle Fock state contributions to heavy-to-light form factors in the context of soft-collinear effective theory and found that they enter at leading power. These contributions are non-factorizable due to the appearance of endpoint singularities, however they do not violate spin-symmetry relations at leading power. In this talk I present their numerical estimation in a crude model in which the “soft overlap” contribution is cut off and find that they might lower the standard values for the form factors at maximum recoil significantly. Furthermore I briefly discuss the role of soft-collinear messenger modes in the region of soft overlap.

PACS: 12.39.St Factorization – 13.20.He Decays of bottom mesons