Decay constants of the heavy-light mesons from the field correlator method

Abstract

Meson Green's functions and decay constants f{sub {gamma}} in different channels {gamma} are calculated using the field correlator method. Both, spectrum and f{sub {gamma}}, appear to be expressed only through universal constants: the string tension {sigma}, {alpha}{sub s}, and the pole quark masses. For the S-wave states the calculated masses agree with the experimental numbers within {+-}5 MeV. For the D and D{sub s} mesons the values of f{sub P}(1S) are equal to 210(10) and 260(10) MeV, respectively, and their ratio f{sub D{sub s}}/f{sub D}=1.24(3), agrees with a recent CLEO experiment. The values f{sub P}(1S)=182, 216, 438 MeV are obtained for the B, B{sub s}, and B{sub c} mesons with the ratio f{sub B{sub s}}/f{sub B}=1.19(2) and f{sub D}/f{sub B}=1.14(2). The decay constants f{sub P}(2S) for the first radial excitations as well as the decay constants f{sub V}(1S) in the vector channel are also calculated. The difference of about 20% between f{sub D{sub s}} and f{sub D}, f{sub B{sub s}} and f{sub B} directly follows from our analytical formulas.