Hadronic J/psi production calculated in the NRQCD factorization formalism

The NRQCD factorization formalism of Bodwin, Braaten, and Lepage prescribes how to write quarkonium production rates as a sum of products of short-distance coefficients times nonperturbative long-distance NRQCD matrix elements. We present a calculation of the inclusive cross section for hadronic psi production within the framework of the factorization formalism. Our method applies to the case in which the helicity of the psi is not measured. In addition to the well-known color-singlet production mechanisms, there are equally important mechanisms in which the c (c) over bar pair that forms the J/psi is initially produced in a color-octet state, in either a S-3(1), S-1(0), P-3(0), or P-3(2) angular-momentum configuration. In our presentation, we faithfully follow the ''matching'' procedure, thereby shedding light on the NRQCD factorization formalism. We determine the short-distance coefficients appearing in the factorization formula, and we point out how one may systematically include relativistic corrections in these calculations.