Study Of J/ψ And ψ’ Decay Into Light Vector And Pseudoscalar Mesons

Chiral Perturbation Theory(χPT)is an effective theory to study the low energy dynamics of QCD and it is based on the global symmetry of QCD.As a consequence,the results from XPT are automatically consistent with the symmetries dictated by QCD.In this thesis,within the framework of the effective Lagrangian approach,we perform a thorough analysis of the J/ψ(ψ’)→PV,J/ψ(ψ’)→ Pγ(γ*),V→Pγ(γ*),P→Vγ(γ*)and P →γγ(γ*)processes,where V stand for light vector resonances,P stand for light pseudoscalar mesons,and γ*decays into lepton pairs.It should be noted that the processes with light pseudoscalar mesons η and η’ are studied within the two-mixing-angle scheme.By making a global fit of the above processes,we update the four mixing parameters,both in singlet-octet and quark-flavor bases,and discuss the interplay between electromagnetic and strong transitions in the J/ψ(ψ’)→ PV decays.