Polarizations of J/\psi and \psi' in hadroproduction at Tevatron in the k_t factorization approach

Abstract

We present a calculation for the polarizations of $J/\psi$ and ${\psi }^{\prime }$ produced in the hadron collisions at the Fermilab Tevatron. Various color octet channels including ${}^1{S}_0^{(8)}$, ${}^3{P}_J^{(8)}$, and ${}^3{S}_1^{(8)}$ as well as contributions from ${\chi }_{cJ}$ decays are considered in the $k_t$ factorization approach. We find that in a rather wide range of the transverse momenta of $J/\psi$ and ${\psi }^{\prime }$, the production rates could be dominated by the ${}^1{S}_0^{(8)}$ channel, and the predicted polarizations from the ${}^1{S}_0^{(8)}$ channel and ${\chi }_{cJ}$ feeddown contributions are roughly compatible with the preliminary CDF data. This might provide a possible release from the conflict between the NRQCD collinear parton model calculations and the CDF data.

Comments: 12 pages, 4 PS files, final version for publication