Abstract
We extract f B from new moments sum rule in the heavy quark effective theory (HQET). We check and improve previous results from Laplace sum rules in HQET by considering all sources of errors including the ones due to the estimated α s 2-term. Averaging these with the ones from the “standard” relativistic sum rules, we deduce the unique QCD spectral sum rules (QSSR) value f B = (1.60 ± 0.32) f π , while in the static limit f B static = (2.07 ± 0.32) f π . The renormalization group invariant coupling in HQET is estimated to be f P ∞ ≅ (0.35 ± 0.07) GeV 3 2 . We find that the linear quark mass dependence of the decay constants is f P √ M P ≅ ( f P √ M P ) ∞ [1 - (0.88 ± 0.18)GeV/ M Q ]. We also show that the moments tend to the Laplace sum rule for M Q →∞.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
