Recently BES at BEPC found evidence for the existence of the σ meson in the process of J/Ψ → σω → ππω. In this paper we firstly discuss the relevant coupling g σππ and show that the linear σ model gives rise to a reasonable description of the σ decay into π's, then we calculate the coupling constant g th J/Ψσω using the perturbative QCD technique and the light-cone wave functions of the σ and ω mesons. The results show that the theoretical value of g th J/Ψσω is within the range of experimental value g J/Ψσω .

Within the framework of the Top-color-assisted Technicolor (TC2) model, we calculate the new physics contributions to the branching ratios B(B s,d → γγ) and CP violating asymmetries r − CP (B s,d → γγ) in the QCD factorization based on the heavy-quark limit m b ≫ Λ QCD . Using the considered parameter space, we find that (a) for both B s → γγ and B d → γγ decays, the new physics contribution can provide a factor of two to six enhancement to their branching ratios, (b) for the B s → γγ decay, its direct CP violation is very small in both the SM and TC2 model, and (c) the CP violating asymmetry r − CP (B d → γγ) is around the ten percent level in both the SM and TC2 model, but the sign of CP asymmetry in the TC2 model is different from that in the SM.

In this paper we firstly study various model-independent bounds on lepton flavor violation (LFV) in processes of J/Ψ, Ψ ′ and Υ two-body decays, then calculate their branch ratios in models of the leptoquark, R violating MSSM and topcolor assisted technicolor(TC2) models.