F. Yuan et Kt. Chao, Polarizations of J/psi and psi ' in hadroproduction at the tevatron in thek(t) factorization approach - art. no. 022002, PHYS REV L, 8702(2), 2001, pp. 2002-NIL_19
We present a calculation for the polarizations of J/psi and psi' produced i
n the hadron collisions at the Fermilab Tevatron. Various color-octet chann
els including S-1(0)(8), P-3(J)(8), and S-3(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 p
si (1), the production rates could be dominated by the S-1(0)(8) channel, a
nd the predicted polarizations from the S-1(0)(8) channel and chi (cJ) feed
-down contributions are roughly compatible with the preliminary CDF data. T
his might provide a possible release from the conflict between the nonrelat
ivistic QCD collinear parton model calculations and the CDF data.