Exclusive photoproduction of Upsilon: from HERA to Tevatron

TL;DR

This paper models exclusive Upsilon photoproduction using pQCD with unintegrated gluon distributions, compares predictions with HERA data, and extends results to hadronic collisions at Tevatron and LHC energies.

Contribution

It introduces a pQCD k_t-factorization approach with constrained gluon distributions to predict Upsilon production in various high-energy processes.

Findings

Good agreement with HERA data on diffractive Upsilon production

Predictions for cross sections at Tevatron and LHC energies

Analysis of the 2S/1S production ratio in diffractive processes

Abstract

The forward photoproduction amplitude for gamma p to Upsilon p is calculated in a pQCD k_t-factorization approach with an unintegrated gluon distribution constrained by inclusive deep-inelastic structure functions. The total cross section for diffractive Upsilons is compared with a recent HERA data. We also discuss the 2S/1S ratio in diffractive Upsilon-production. The amplitude is used to predict the cross section for exclusive Upsilon production in hadronic reactions. Differential distributions for the exclusive p pbar to p Upsilon pbar process are calculated for Tevatron energies. We also show predictions for LHC. Absorption effects are included.