Testing Quarkonium Production with Photoproduced $J/\psi +\gamma$

Abstract

I compute the leading color-octet contributions to the process $\gamma +p\to J/\psi +\gamma (+X)$ within the non-relativistic QCD (NRQCD) factorization formalism. In the color-singlet model, $J/\psi +\gamma$ can only be produced when the photon interacts through its structure function, while the color-octet mechanism allows for production of $J/\psi +\gamma$ via direct photon-gluon fusion. Resolved photon processes can be easily be distinguished from direct photon processes by examining the fraction of the incident photon energy carried away by the $J/\psi$ in the event. Therefore, this process provides a conclusive test of the color-octet mechanism. $J/\psi +\gamma$ production is particularly sensitive to the NRQCD matrix element which figures prominently in the fragmentation production of $J/\psi$ at large $p_{\perp }$ in hadron colliders. I also examine the predictions of the color evaporation model (CEM) of quarkonium production and find that this process can easily discriminate between the NRQCD factorization formalism and the CEM.

uses Revtex, 12 pages, 4 EPS figures embedded using epsf.sty. Some references have been added. Version accepted for publication in Phys. Rev. D

References in corpus (14)

• Rigorous QCD Analysis of Inclusive Annihilation and Production of Heavy Quarkonium
• Color-octet quarkonia production
• Color-Octet Fragmentation and the psi' Surplus at the Tevatron
• QCD Corrections to Inelastic $J/\psi$ Photoproduction
• Fragmentation production of J/psi and psi' at the Tevatron
• Color-Octet Contributions to $J/\psi$ Photoproduction
• Production of Heavy Quarkonium in High Energy Colliders
• Hadro-production of Quarkonia in Fixed Target Experiments
• J/psi Production via Fragmentation at the Tevatron
• Color-octet mechanism in $\gamma +p\to J/\psi +X$
• Helicity Decomposition for Inclusive $J/\psi$ Production
• Quarkonium Decay Matrix Elements from Quenched Lattice QCD
• Colorless States in Perturbative QCD: Charmonium and Rapidity Gaps
• Systematics of quarkonium production

Cited by in corpus (15)

• Quarkonium Production at High-Energy Colliders
• Theory of hard photoproduction
• Analogies between dark solitons in atomic Bose-Einstein condensates and optical systems
• Associated Production of Heavy Quarkonia and Electroweak Bosons at Present and Future Colliders
• Deformation of dark solitons in inhomogeneous Bose-Einstein condensates
• J/psi plus prompt-photon associated production in two-photon collisions at next-to-leading order
• Azimuthal asymmetries in $J/\psi$-photon production at the EIC
• Associated J/psi + gamma Photoproduction as a Probe of the Colour-Octet Mechanism
• Diffractive quarkonium production in association with a photon at the LHC
• J/psi Production in an Equilibrating Partonic System
• Quarkonium+$\gamma$ production in coherent hadron - hadron interactions at LHC energies
• Associated production of $J/\psi$ and direct photon in the NRQCD and the ICEM using the high-energy factorization
• Quarkonium plus prompt-photon associated hadroproduction and nuclear shadowing
• Heavy-Flavour Production at HERA
• Next-to-leading order analysis of $J/\psi +\gamma$ production in photon-photon collisions at CEPC