The evasion of helicity selection rule in $\chi_{c1}\to VV$ and $\chi_{c2}\to VP$ via intermediate charmed meson loops

Understand

The hadronic decays of $\chi_{c1}\to VV$ and $\chi_{c2}\to VP$ are supposed to be suppressed by the helicity selection rule in the pQCD framework.

• With an effective Lagrangian method, we show that the intermediate charmed meson loops can provide a mechanism for the evasion of the helicity selection rule, and result in sizeable decay branching ratios in some of those channels.
• The theoretical predictions can be examined by the forthcoming BES-III data in the near future.