6533b821fe1ef96bd127b71f

RESEARCH PRODUCT

Unified QCD determination of all pseudoscalar leptonic decay constants

subject

description

Leptonic decay constants of all pseudoscalar mesons are determined in QCD by means of a new QCD sum-rule method. In the light meson and heavy quark limit the results are very similar and also agree with the well-known PCAC and scaling predictions respectively. The corrections to light meson pole dominance are generally small while those to the heavy quark limit are found to be sensitive to the binding energy (i.e. meson and quark mass differences). For standard values of quark masses we obtainfπ=132 MeV,fk=161 MeV,fB=128±28 MeV,fD=175±13 MeV,fBs=144±30 MeV andfDs=193±12 MeV.