χcJ polarizations at the Fermilab Tevatron

We propose the measurement of χcJ polarizations at high energy hadron colliders to study heavy quarkonium production mechanism. We find that the color-singlet model in the kt factorization approach predicts very different behavior for χcJ polarizations at the Fermilab Tevatron compared with the NRQCD predictions in the collinear parton model. In the color-singlet kt factorization approach, for both χc1 and χc2 productions, the helicity h=0 states dominate over other helicity states at large pT. These properties are very useful in distinguishing between the two production mechanisms which are related to the interesting issue of Jψ and ψ′ polarizations, and may provide a crucial test for the kt factorization approach.