OPE, HeavyQuark Mass, and HeavyMeson Decay Constants from QCD Sum Rules
Abstract
We present a sumrule extraction of the decay constants of heavylight mesons from the twopoint correlator of pseudoscalar currents. To this end, we compare the perturbative expansions for the correlator and the decay constant performed in terms of either the pole mass or the running MSbar mass of the heavy quark. The perturbative expansion expressed in terms of the pole mass exhibits no sign of convergence whereas reorganizing this very expansion in terms of the MSbar mass yields a rather clear hierarchy of the perturbative contributions. Accordingly, the decay constants extracted from the polemass correlator turn out to be considerably smaller than those extracted from its MSbarmass counterpart. Then, making use of the OPE in terms of the MSbar mass we derive the decay constants of heavy mesons with emphasis on acquiring control over the uncertainties in the decay constants, related both to the input QCD parameters and to the limited accuracy of the method of sum rules. Gaining this control has become possible due to the application of our novel procedure for extracting hadron observables based on dual thresholds which depend on the Borel parameter.
 Publication:

arXiv eprints
 Pub Date:
 November 2010
 arXiv:
 arXiv:1011.3723
 Bibcode:
 2010arXiv1011.3723L
 Keywords:

 High Energy Physics  Phenomenology;
 High Energy Physics  Experiment;
 High Energy Physics  Lattice;
 Nuclear Theory
 EPrint:
 talk presented at the "XIXth International Workshop on High Energy Physics and Quantum Field Theory  QFTHEP'10", 8  15 September 2010, Golitsyno, Moscow, Russia