We investigate the inclusive production of prompt J/ψ mesons in polarized hadron-hadron and photon-hadron collisions in the factorization formalism of NRQCD. Numerical results are presented for BNL RHICSpin and the approved SLAC fixed-target experiment E161 to assess the feasibility to access the spin-dependent parton distributions in the polarized proton and photon. We point out that data on J...

I present a definition of the cross section for the production of an isolated photon plus n jets which only depends upon direct photon production, and it is independent of the parton-to-photon fragmentation contribution. This prescription, based on a modified cone approach which implements the isolation condition in a smooth way, treats in the same way quarks and gluons and can be directly appl...