Decay constants of the charmed vector mesons D^{⁎} and D_{s}^{⁎} from QCD sum rules
Abstract
We present a sumrule calculation of the decay constants of the charmed vector mesons D^{⁎} and D_{s}^{⁎} from the twopoint correlator of vector currents. First, we show that the perturbative expansion in terms of the pole mass exhibits no sign of convergence whereas the reorganization of this expansion in terms of the MS bar mass leads to a distinct hierarchy. Second, making use of the operator product expansion in terms of the MS bar mass, we determine the decay constants of the D^{⁎} and DSUB>s^{⁎} mesons with an emphasis on the uncertainties in these theoretically predicted quantities related both to the input QCD parameters and to the limited accuracy of the method of sum rules. Our results are f_{D⁎} = (252.2 ±22.3_{OPE} ±4_{syst}) MeV and _{f Ds⁎} = (305.5 ±26.8_{OPE} ±5_{syst}) MeV. For the ratios of the vectortopseudoscalar decay constants we report f_{D⁎} /f_{D} = 1.221 ±0.080_{OPE} ±0.008_{syst} and _{f Ds⁎} /f_{Ds} = 1.241 ±0.057_{OPE} ±0.007_{syst}.
 Publication:

Physics Letters B
 Pub Date:
 July 2014
 DOI:
 10.1016/j.physletb.2014.06.007
 arXiv:
 arXiv:1404.0293
 Bibcode:
 2014PhLB..735...12L
 Keywords:

 High Energy Physics  Phenomenology
 EPrint:
 9 pages, published version