Study On The J/ψ,γ Nonleptonic Two-body Weak Decays With QCD Factorization

At present, there exist two general trends in particle physics. One is very high energy frontier, for example the Large Hadron Collider which will permit to discover new particles, explore new phenomena and look for new physics signals at high energy. The other is very large intensity frontier, such as the BES, B-factories, Super c-τ factory and SuperB factory, those aim at giving more precise tests and strict determinations of the parameters in Standard Model by collecting high statistics of low background samples. More than 10~9 J/ψ samples, and more than 10~8 γ(nS) samples have been collected at BES and B-factories (BaBar and Belle) respectively. With the running of high-luminosity dedicated heavy-flavor physics experiments, more and more J/ψ and γ(nS) samples will be accumulated, which provided a good opportunity for the study of heavy-flavor quarkonium.J/ψ, consists of c(?), is smaller than the D(?) threshold; γ(nS), consists of b(?), is smaller than the BB threshold. They have the same JPC quantum number, and decay into hadrons dominated via the strong and electromagnetic interactions, but strong decay is suppressed by OZI mechanism. Beside, in Standard Model the heavy-flavor quarkonium can decay into hadrons also via the weak interaction which are promisingly detected at the high-luminosity heavy-flavor experiments in the forthcoming years.For the nonleptonic weak decays, there exists the participation of strong interaction, where the perturbative and non-perturbative contributions entangled with each other, which makes theoretical calculation very complicated. In recent years, several attractive methods have been developed and successfully used to treat with the hadronic matrix elements of heavy flavor weak decay, based on the factorization approximation, power countering rules and perturbative QCD calculation. In this paper, we present a phenomenological study on the heavy flavor quarkonium two-body nonleptonic J/ψ→ DP, DV and γ(nS) → BCP, BcV weak decays. The branching ratios of the weak decays are estimated by considering QCD one-loop vertex corrections to the hadronic matrix with the QCDF approach. The nonfactorizable contribution to hadronic matrix elements and the information on strong phases are obtained, and the uncertainties of the theoretical parameters are discussed. The results show that the CKM favored and W external emission processes have relatively large branching ratios. The magnitude of the branching ratios for J/ψ→ Dsρ and γ(nS)→Bcρ decays can reached up to 10-9 and 10-10 respectively, which might be promisingly detectable at c-τ factory, SuperB factory and LHCb experiments. Our results will offer a reference for searching the J/ψ and γ(nS) weak decays on experiments.