Impact of ${\eta }_c$ hadroproduction data on charmonium production and polarization within NRQCD framework

Hong-Fei Zhang, Zhan Sun, Wen-Long Sang +1

With the recent LHCb data on ${\eta }_c$ production and based on heavy quark spin symmetry, we obtain the long-distance matrix elements for both ${\eta }_c$ and $J/\psi$ productions, among which,…