Chi_2 production in polarized pp collisions at RHIC: measuring ΔG and testing the color octet model

Abstract

We consider the production and decay of the ${\chi }_2$ charmonium state in polarized and unpolarized $pp$ collisions at RHIC in the framework of an effective theory based on the QCD multipole expansion. We find that the angular distribution in the decay of the produced charmonium, ${\chi }_2\to J/\psi +\gamma$, in the unpolarized case allows us to distinguish clearly between the color singlet and color octet production mechanisms. Once the production mechanism is known, the angular distribution in the polarized case can be used to measure the polarized gluon distribution in the proton, $\Delta G(x)$.

7 pages

References in corpus (1)

• Theoretical Interpretations of J/Psi Suppression: A Summary

Cited by in corpus (5)

• Prospects for Spin Physics at RHIC
• Quarkonium polarization in heavy ion collisions as a possible signature of the quark--gluon plasma
• Detect ΔG at BNL-RHIC via Double Quarkonium Production
• Quarkonium Production through Hard Comover Rescattering in Polarized and Unpolarized pp Scattering
• Detect Gluon Polarisation at BNL-RHIC Through J/ψPair Production Process