Heavy quark induced effective action for gauge fields in the SU(N-c) circle times U(1) model and the low-energy structure of heavy quark current correlators

We calculate the low-energy limit of heavy quark current correlators within an expansion in the inverse heavy quark mass. The induced low-energy curre nts built from the gluon fields corresponding to the initial heavy quark cu rrents are obtained from an effective action for gauge fields in the one-lo op approximation at the leading order of the 1/m expansion. Explicit formul ae for the low-energy spectra of electromagnetic and tensor heavy quark cur rent correlators are given. Consequences of the appearance of a nonvanishin g spectral density below the two-particle threshold for high precision phen omenology of heavy quarks are discussed quantitatively.