Determination of electric dipole transitions in heavy quarkonia using potential non-relativistic QCD

Abstract

The electric dipole transitions with J = 0, 1, 2 and are computed using the weak-coupling version of a low-energy effective field theory named potential non-relativistic QCD (pNRQCD). In order to improve convergence and thus give firm predictions for the studied reactions, the full static potential is incorporated into the leading order Hamiltonian_s19 moreover, we must handle properly renormalon effects and re-summation of large logarithms. The precision we reach is , where kÎ_s11 is the photon energy, m is the mass of the heavy quark and v its velocity. Our analysis separates those relativistic contributions that account for the electromagnetic interaction terms in the pNRQCD Lagrangian which are v 2 suppressed and those that account for wave function corrections of relative order v 2. Among the last ones, corrections from 1/m and 1/m2 potentials are computed, but not those coming from higher Fock states since they demand non-perturbative input and are or suppressed, at least, in the strict weak coupling regime. These proceedings are based on the forthcoming publication [1].