χQJ → l+l- within and beyond the Standard Model

We revisit chi(QJ) -> l(+)l(-) (with J = 0, 1, 2 and Q = b, c) within the Standard Model (SM). The electromagnetic contributions are given in the color-singlet model with non-vanishing lepton masses at the leading order of v. Numerically, the branching ratios of chi(QJ) -> l(+)l(-) predicted within the SM are so small that such decays are barely possible to be detected at future BESIII and SuperB experiments, but may be possible to be observed at the LHC. We investigate chi(b0) -> l(+)l(-) in Type-II 2HDM with large tan beta, and chi(b2) -> l(+)l(-) in the Randall-Sundrum model, to see their chance to be observed in future experiments.