标题： $η_c$重强子产生数据对NRQCD框架下J/ψ粒子产生和极化的影响 显示英文标题

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

摘要： 基于最近的LHCb关于$\eta_c$产生数据，并利用重夸克自旋对称性，我们得到了$\eta_c$和$J/\psi$产生的长程矩阵元，其中$\eta_c$的色单态矩阵元首次通过实验拟合直接获得。 利用我们的长程矩阵元，我们可以对$\eta_c$和$J/\psi$的强子产生测量结果进行良好的描述。 我们对$J/\psi$极化的预测与LHCb数据高度一致，并且在中等$p_t$区域内通过了两组CDF测量数据。 仔细考虑所有可能的不确定性后，我们得到了$J/\psi$极化曲线的非常狭窄的范围。 显示英文摘要

摘要： 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, the color-singlet one for $\eta_c$ 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 $\eta_c$ and $J/\psi$ hadroproduction measurements. Our predictions on $J/\psi$ polarization are in good agreement with the LHCb data and pass through the two sets of CDF measurements in medium $p_t$ region. Considering all the possible uncertainties carefully, we obtained quite narrow bands of the $J/\psi$ polarization curves.