Accurate decay-constant ratios fB*/fB and fBs*/fBs from Borel QCD sum rules

Author(s)
Wolfgang Lucha, Dmitri Melikhov, Silvano Simula
Abstract

We present our analysis of the decay constants of the beauty vector mesons B* and B-s* within the framework of dispersive sum rules for the two-point correlator of vector currents in QCD. While the decay constants of the vector mesons f(B*) and f(Bs*)-similar to the decay constants of the pseudoscalar mesons f(B) and f(Bs)-individually have large uncertainties induced by theory parameters not known with a satisfactory precision, these uncertainties almost entirely cancel out in the ratios of vector over pseudoscalar decay constants. These ratios, thus, may be predicted with very high accuracy due to the good control over the systematic uncertainties of the decay constants gained upon application of our hadron- parameter extraction algorithm. Our final results read f(B*)/f(B) = 0.944 +/- 0.011(OPE) +/- 0.018(syst) and f(Bs*)/f(Bs) = 0.947 +/- 0.023(OPE) +/- 0.020(syst). Thus, both f(B*)/f(B) and f(Bs*)/f(Bs) are less than unity at 2.5 sigma and 2 sigma level, respectively.

Organisation(s)
Particle Physics
External organisation(s)
Österreichische Akademie der Wissenschaften (ÖAW), Lomonosov Moscow State University (MSU), Universität Wien, Istituto Nazionale di Fisica Nucleare (INFN), Roma
Journal
Physical Review D
Volume
91
No. of pages
10
ISSN
1550-7998
DOI
https://doi.org/10.1103/PhysRevD.91.116009
Publication date
06-2015
Peer reviewed
Yes
Austrian Fields of Science 2012
103034 Particle physics
Keywords
Portal url
https://ucris.univie.ac.at/portal/en/publications/accurate-decayconstant-ratios-fbfb-and-fbsfbs-from-borel-qcd-sum-rules(c19fd942-3868-4cdc-94ef-59d08854ee7e).html