W Decays To The Excited Heavy-Flavor Menson At LHC

Research on the production and decay of double heavy flavor quarkonium is not only a precise test for Standard Model, but also plays an important role for seeking for the New Physics. In the course of studying the heavy-quarkonium, we start from the perturbative quantum chromodynamics(pQCD), then develop and perfect the non-relativistic quantum chromodynamics(NRQCD), which factorizes the cross section or decay width of heavy-quarkonium as the product of a series of short-distance coefficents and long-distance ones. The former short-distance quantities can be calculated perturbatively by using pQCD, while the latter long-distance ones can be obtained via lattice gauge theory, potential model or experiments. In our paper, within the NRQCD factorization approach we have studied the processes of W+boson decays to the double heavy flavor quarkonium (cc),(cb} and (bb) both in detail and systematically, not only the S-Wave and P-Wave of those, but also the higher excited states.Firstly, we present the discussion of the processes of W+boson decays to two final states, i.e. three leptonic decays W+â†'l+vt, six inclusive decays W+â†'q+q and four heavy-quarkonium decays W+â†'(QQ)+(Q1Q1).We find out that our estimates are quite consistent with the experiments.Then we concentrate on the inclusive decays of â…£ boson decays to the double heavy flavor quarkonium, i.e.(cc),(cb} and (bb),both S-Wave and P-Wave of those quarkonium are included. Under the perturbative QCD and non-relativistic QCD frame, in order to get the analytical expression of the three final states decay processes, the improved trace technology, or trace technology at the amplitude level is adopted. We have obtained the decay widths of the semi-leptonic decay processes of PV boson decays to S-Wave and P-Wave double heavy flavor quarkonium i.e.(cc),(cb} and (bb), and the differential distributions of the decay widths for the invariable masses s1,s2, and for the outgoing particles included angles cosθ13and cosθ23, for the relevant four channels. Moreover, the uncertainties of the width and differential width for the quark masses are presented. What’s more, we also calculate the events of those double heavy flavor quarkonium under the LHC experiments conditions which may be useful for experimental physicists. At last, we carry a research on the higher excited S-Wave and P-Wave states of those heavy-quarjonium (cc),(cb} and (bb). In the same way, we also give a presentation of decay widths, differential distributions for s1,s2, cosθ13and cosθ23. In addition, a ratio of higher states decay width to ground states’is presented. Besides, we have carried out a discussion on the decay widths of W+boson decays to the ground and excited states in different potential models. These results are helpful and meaningful to the experiments in future, especially for the study of W physics, charmonium and B physics. Meanwhile, those results can be a sound reference to decide which potential model which describes the interaction between quarks in the heavy-quarkonium is better, or guidance for the theory development.