Chromopolarizability of charmonium and $pipi$ final state interaction revisited

The chromopolarizability of a quarknonium describes the quarknoniums interaction with soft gluonic fields and can be measured in the heavy quarkonium decays. Within the framework of dispersion theory which consider the $pipi$ final state interaction (FSI) model-independently, we analyze the transition $psi^primeto J/psipi^+pi^-$ and obtain the chromopolarizability $alpha_{psi^prime psi}$ and the parameter $kappa$. It is found that the $pipi$ FSI plays an important role in extracting the chromopolarizability from the experimental data. The obtained chromopolarizability with the FSI is reduced to about 1/2 of that without the FSI. With the FSI, we determine the chromopolarizability $|alpha_{psi^primepsi}|=(1.44pm 0.02)$ GeV$^{-3}$ and the parameter $kappa=0.139pm 0.005.$ Our results could be useful in studying the interactions of charmonium with light hadrons.