A Precise Study Of QCD Sum Rule Approach For Heavy Flavor Meson Semileptonic Decay

In this paper,we were calculated D??,D? P(?,K)and Bc?(?c,J/?)semileptonic decay by applying the QCD light-cone sum rule(LCSR)approach.Heavy flavor physics is the frontier and hot-spot of particle physics re-search at present.Firstiy,the measured branching ratio of the D-meson semilep-tonic decay D??e+ve,which is based on the 0.82 fb-1 CLEO data taken at the peak of ?(3770)resonance,disagrees with the traditional Shifman-Vainshtein-Zakharov(SVZ)sum rules analysis by about three times.In the paper,we show that this discrepancy can be eliminated by applying the QCD light-cone sum rules(LCSR)approach to calculate the D?p transition form factors and the branching ratios.we obtain(?)and(?),which agree with the CLEO measurements within errors.We also calculate the branching ratios of the two D meson radiative processes and obtain(?)and(?),which also agree with the Belle measure-ments within errors.Secondly,the calculation of the D? P(?,K)decay process.The resultant HFFs at(?)We obtain the decay widths and the branching fractions for semileptonic decay processes of D? Plve,our predictions also agree with BES-? collaboration within errors,especially for D??lvl decay process.Finally,we present the forward-backward asymmetry AFBl(q2)and lepton convexity parameter CFl(q2),and further calculate the mean value of these two observations<AFBl>and<CFl>,which may provide a way to test those HFFs in future experiments.Finally,new physics in the Bc semileptonic decay processes might be neces-sary to address anomalies between experimental and theoretical predictions.In this paper,we discussed Bc??c and Bc?J/? semileptonic decays within the Standard Model and beyond.We calculate the semileptonic branching fractions and find for the ratios,(?)Both predic-tions are in agreement with other existing calculations and support the current tension in RJ/? at 2a level with the experiment.So it is very important to cal-culate the Bc semileptonic decay processes of new physics(NP).Meanwhile this paper calculated the forward-backward asymmetry AFB,the convexity parameter CF? and the longitudinal polarization PL and transverse polarizationPT.