HELICITY DECOMPOSITION FOR INCLUSIVE J PSI PRODUCTION/

We present a general method for calculating inclusive cross sections f or the production of heavy quarkonium states with definite polarizatio n within the NRQCD factorization approach. Cross sections for polarize d production can involve additional matrix elements that do not contri bute to cross sections for unpolarized production. They can also inclu de interference terms between parton processes that produce Q (Q) over bar pairs with different total angular momentum. The interference ter ms cancel upon summing over polarizations. Our method can be generaliz ed to N dimensions and Is, therefore, compatible with the use of dimen sional regularization to calculate radiative corrections. We illustrat e the method by applying it to the production of J/psi via the parton processes q (q) over bar --> c (c) over bar and gg --> c (c) over bar.