Decoupling heavy particles simultaneously
Tipo
Artigo
Data de publicação
2005
Periódico
Nuclear Physics B - Proceedings Supplements
Citações (Scopus)
4
Autores
Crewther R.J.
Bass S.D.
Steffens F.M.
Thomas A.W.
Bass S.D.
Steffens F.M.
Thomas A.W.
Orientador
Título da Revista
ISSN da Revista
Título de Volume
Membros da banca
Programa
Resumo
The renormalization group is extended to cases where several heavy particles are decoupled at the same time. This involves large logarithms which are scale-invariant and so cannot be eliminated by a change of renormalization scheme. A set of scale-invariant running couplings, one for each heavy particle, is constructed without reference to intermediate thresholds. The entire heavy-quark correction to the axial charge of the weak neutral current is derived to next-to-leading order, and checked in leading order by evaluating diagrams explicitly. The mechanism for cancelling contributions from the top and bottom quarks in the equal-mass limit is surprisingly non-trivial. © 2004 Elsevier B.V. All rights reserved.