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

TL;DR

This paper demonstrates that intermediate charmed meson loops can bypass the helicity selection rule, leading to significant decay rates in certain $ ext{chi}_c$ hadronic decays, which can be tested by upcoming experimental data.

Contribution

It introduces a mechanism involving charmed meson loops that evades the helicity selection rule in $ ext{chi}_c$ decays, providing new theoretical predictions.

Findings

Charmed meson loops enable sizable decay branching ratios.

The mechanism explains observed decay rates beyond pQCD expectations.

Predictions are testable with upcoming BES-III data.

Abstract

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.