Decay Properties of QQ̄ Mesons in Potential Models and Effective Field Theories

The decay rates of QQ̄ mesons (Q ε c,b) are studied in the NRQCD formalism in terms of their short distance and long distance coefficients. The long distance coefficients are obtained through phenomenological potential model description of the mesons. The mass spectrum of the cc̄ and bb̄ mesons are reviewed in non-relativistic phenomenological quark antiquark potential of the type V (r) = −αc r + Arν , with ν varying from 0.5 to 2. The spin hyperfine and spin-orbit interactions are employed to obtain the masses of the pseudoscalar and vector mesons. The digamma and dileptonic decays of cc̄, and bb̄ mesons are investigated using some of the known potential models by incorporating radiative corrections up to the lowest order. The heavy quarkonium decays into two photons, and the vector state into lepton pairs are computed within the NRQCD formalism. Our theoretical predictions of the decays of the cc̄ and bb̄ mesons and the results obtained from some of the other potential schemes are compared with the experimental values.