Isospin breaking in heavy-meson decay constants

Wolfgang Lucha, Dmitri Melikhov, Silvano Simula

Evaluation of Borelized QCD sum rules in the so-called local-duality limit of infinitely large Borel mass parameter provides an alternate route for extraction of the dependence of the decay constants of heavy–light mesons on the mass mq of the involved light quark q: For appropriate choices of the two-point correlation functions of currents interpolating the hadrons under study, the local-duality limit forces all nonperturbative contributions parametrized by vacuum condensates to such kind of correlator to vanish. As a consequence, the sought mq dependence of the heavy–light meson decay constants proves to be controlled primarily by the correlator contributions from perturbative QCD. Our knowledge of the analytic behaviour of the latter as functions of mq enables us to derive the mq dependence of the decay constants of both pseudoscalar and vector heavy–light mesons, for which we estimate strong isospin breaking to be of the order of 1 MeV for both charm and beauty sectors.

Particle Physics
External organisation(s)
Österreichische Akademie der Wissenschaften (ÖAW), Lomonosov Moscow State University (MSU), Universität Wien, Istituto Nazionale di Fisica Nucleare (INFN), Roma
Proceedings of Science (PoS)
No. of pages
Publication date
Peer reviewed
Austrian Fields of Science 2012
103034 Particle physics
ASJC Scopus subject areas
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