Study Of The Strong Decays Of Hadrons With One Charm Quark

Since it was proposed in the 1970s,Quantum Chromodynamics(QCD)has made a lot of success in describing strong interactions.QCD has three basic features,which are quark confinement,asymptotic freedom and chiral symmetry breaking.In high energy sector,it has exact solutions for strong interaction by using perturbation theory.However,in middle and low energy sectors,the nonperturbative effect becomes distinct and this leads to the failure of perturbation theory.To solve this problem,nonperturbation theory has to be employed.Nonperturbation theory includes many methods,including the lattice QCD theory,the QCD sum rules and the phenomenological quark models.The Lattice QCD theory realize its calculations based on discrete lattice.As the exactitude of results in lattice QCD depends heavily on the computer's performance,and with higher exactitude it re-quires longer time,the lattice QCD has its limitations.Phenomenological quark models are methods with most users and researchers so far,which include different models like the potential model,the chiral quark model,the flux tube model,the quark-pair creation model(3Po model)and so on.Of all these phenomenological models,3P0 model has made a lot of success in describing OZI-rule allowed strong decays though it is not de-rived from the original QCD theory.This has gained it much attention from researchers.In hadron sector,the states of mesons and baryons without excitation and with low-lying excitations are believed to established through the development of recent decades.As more and more highly excited states of mesons and baryons are reported experimen-tally,and as it's important for us in understanding strong interactions and the inner struc-ture of hadrons,to study their quantum assignments has become a major task.For the purpose of providing information in establishing these highly excited hadrons with one charm quark,the thesis will study their decay properties by employing 3P0 model.3P0 model is introduced in detail of its use in the strong decays of both mesons and baryons in Chapter Two,also in this chapter the parameters of this model and their uncertainties they may bring is discussed.Charmed meson is the typical heavy-light system and studying the strong decays of them can be help in understanding of strong interactions.It is believed that the states without excitations and with low orbital excitations have been established in charmed meson sector,and with higher and higher energy of the observed charmed mesons in experiments,it has attracted a lot of research interests in high orbital and radial excitation states.The strong decay properties of 2D-wave charmed mesons have been studied in the framework of 3P0 model in Chapter Three.Also in this chapter,analysis of the hadroinc production of D(2550),D*(2600),D(2750),D1*(2760)and D3*(2760)has has been conducted.Later the hadroinc decay studies of three newly observed charmed mesons with close masses DJ(3000),D*(3000)and D2*(3000)are conducted in the end of this chapter as well.Some explanations and predictions have been made.The effective values of ? calculated from potential quark model are adopted in the model.?c and ?c are charmed baryons with one charm quark.In recent years more and more charmed baryons with excitations have been observed in experiments and it seems that much attention has been spent on these baryons,especially their strong decays.It is also in the framework of 3 P0 model that the researches and analysis of ?c(3055)and?c(3080)as well as the five newly observed excited ?c states are conducted in Chapter Four.?c(3055)is possibly a 1D-wave charmed baryon while the assignment of ?c(3080)is not predicted and needs further study.The five newly observed excited ?c baryons are likely to be the 1P or 1D-wave states.The results in this chapter for ?c,baryons are lower than the experimental data but still within the uncertainties,while the results for?c,baryons are consistent with the experimental data.Hadronic decay properties of highly excited mesons and baryons with one heavy quark has been studied in the framework of 3 P0 model in Chapter Three and Chapter Four,respectively,with relevant analysis and predictions.It may provide some directions or references in the forthcoming experiments.In the last chapter,some summary and prospect are given.