The exclusive $J/\psi$ process at the LHC tamed to probe the low $x$ gluon

Abstract

The perturbative QCD expansion for $J/\psi$ photoproduction appears to be unstable: the NLO correction is large (and of opposite sign) to the LO contribution. Moreover, the predictions are very sensitive to the choice of factorization and renormalization scales. Here we show that perturbative stability is greatly improved by imposing a $‘Q_0$ cut' on the NLO coefficient functions; a cut which is required to avoid double counting. $Q_0$ is the input scale used in the parton DGLAP evolution. This result opens the possibility of high precision exclusive $J/\psi$ data in the forward direction at the LHC being able to determine the low $x$ gluon distribution at low scales.

arXiv comment14 pages, 5 figures. Final paragraph of Sect. 3.2 added. Version to be published in EPJC

References in corpus (14)

• Gauge-Invariant Decomposition of Nucleon Spin and Its Spin-Off
• Implications of CTEQ global analysis for collider observables
• Nonforward Parton Distributions
• Asymmetric Gluon Distributions and Hard Diffractive Electroproduction
• NLO Production and Decay of Quarkonium
• One-Loop Corrections and All Order Factorization In Deeply Virtual Compton Scattering
• Order-v^4 Corrections to S-wave Quarkonium Decay
• Exclusive photoproduction of a heavy vector meson in QCD
• Wavefunction corrections and off-forward gluon distributions in diffractive J/psi electroproduction
• Exclusive $J/\psi$ and ${\rm Y}$ photoproduction and the low $x$ gluon
• Small x gluon from exclusive J/psi production
• Sudakov effects in photon-initiated processes
• Drell-Yan as a probe of small x partons at the LHC
• Probing GPDs in Ultraperipheral Collisions

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