Associated production of prompt photons and heavy quarks in off-shell gluon-gluon fusion

TL;DR

This paper investigates prompt photon and heavy quark production in high-energy hadron collisions using the kt-factorization approach, comparing theoretical predictions with experimental data and exploring angular correlations to test gluon density models.

Contribution

It introduces a detailed calculation of prompt photon and heavy quark production via off-shell gluon fusion, incorporating two gluon distribution models and analyzing angular correlations.

Findings

Theoretical cross sections agree with Fermilab Tevatron data.

Angular correlations are sensitive to gluon density models.

Predictions for LHC energies are provided.

Abstract

In the framework of the kt-factorization approach, we study the production of prompt photons associated with heavy (charm and beauty) quarks in hadron-hadron collisions at high energies. Our consideration is based on the amplitude for the production of a single photon associated with a quark pair in the fusion of two off-shell gluons. The total and differential cross sections are presented and the conservative error analysis is performed. Two sets of unintegrated gluon distributions in the proton have been used in numerical calculation: the one obtained from Ciafaloni-Catani-Fiorani-Marchesini evolution equation and the other from Kimber-Martin-Ryskin prescription. The theoretical results are compared with recent experimental data taken by the CDF collaboration at the Fermilab Tevatron. Our analysis extends to specific angular correlations between the produced prompt photons and muons originating from semileptonic decays of the final charmed or beauty quarks. We point out the importance of such observables, which can serve as a crucial test for the unintegrated gluon densities in a proton. Finally, we extrapolate the theoretical predictions to the CERN LHC energies. This paper is dedicated to the memory of P.F. Ermolov, who died on May 14, 2008.