Two-Spin Asymmetry for ψ′ Photoproduction with Color-Octet Mechanism

الأصل · EN

We studied the photoproduction of ψ′ in the forward regions in polarized γp collisions at relevant HERA energies. We found that this reaction is very effective to test the color-octet mechanism which is based on the NRQCD factorization formalism. Furthermore we found that the value of the NRQCD matrix elements can be severely constrained by measuring the two-spin asymmetry, though the process depends on the polarized gluon distribution Δg(x).