Tests of the infinite mass effective theory and properties of the charming and beautiful mesons

Using an operator product expansion (OPE) in the inverse of the heavy quark massM _Q and a dispersive approach, we rederive theB andB ^* couplings and the Isgur-Wise function predicted by the infinite mass effective theory (IMET). We find that, at the subtraction pointM _Q and using VDM for the spectral function, these observables are governed by the universal light quark condensate. We also find that the corrections induced by finite values ofM _c andM _b are large and are due to the splitting _b between the ground state and its radial excitation. We review the determinations of the different decay constants, couplings and masses from QCD spectral sum rules (QSSR). Forf _B andf _D , we conclude the optimum average:f _B =(1.59±0.09±0.27)f andf _D =(1.31±0.12)f , where the main error is due to the quark mass, while the first one inf _B is due to the non-perturbative terms and to the choice of the continuum thresholdt _c from the onset of sum rule variable stability until thet _c -stability regions. We also find that the vector coupling _V satisfies approximately the IMETM _Q ^3/2 mass dependence scaling law, whilef _P obeys in units of GeV:f P/f(4.6±0.4)M _Q ^–1/2 (1–1.56/M _Q +0.88/M _Q ² ), forM _Q M _c . We also predict the flavour independence:M _P -M _Q 0.6-0.7 GeV andM _V -M _Q 0.7-0.8 GeV of the mass differences between the mesons and the corresponding quark. Finally we find that theBDev _e form factorf ₊(0)(0.55±0.10) deviates from the naive expectation (f ₊(0)=1).