Impact of $η_c$ hadroproduction data on charmonium production and polarization within NRQCD framework

Paper

Abstract

With the recent LHCb data on

production and based on heavy quark spin symmetry, we obtain the long-distance matrix elements for both

and

productions, among which, the color-singlet one for

is obtained directly by the fit of experiment for the first time. Using our long-distance matrix elements, we can provide good description of the

and

hadroproduction measurements. Our predictions on

polarization are in good agreement with the LHCb data and pass through the two sets of CDF measurements in medium

region. Considering all the possible uncertainties carefully, we obtained quite narrow bands of the

polarization curves.