Diphoton production at Tevatron in the quasi-multi-Regge-kinematics approach

TL;DR

This paper models prompt diphoton production at Tevatron using the quasi-multi-Regge-kinematics approach with Reggeized quarks and gluons, accurately matching experimental data without free parameters.

Contribution

It introduces a novel application of Reggeization in diphoton production and demonstrates precise data description without free parameters.

Findings

Main contribution from Reggeized gluon fusion into diphotons.

Significant contribution from Reggeized quark-antiquark annihilation.

Accurate data description using unintegrated parton distributions.

Abstract

We study the production of prompt diphotons in the central region of rapidity within the framework of the quasi-multi-Regge-kinematics approach applying the hypothesis of quark and gluon Reggeization. We describe accurately and without free parameters the experimental data which were obtained by the CDF Collaboration at the Tevatron Collider. It is shown that the main contribution to studied process is given by the direct fusion of two Reggeized gluons into a photon pair, which is described by the effective Reggeon-Reggeon to particle-particle vertex. The contribution from the annihilation of Reggeized quark-antiquark pair into a diphoton is also considered. At the stage of numerical calculations we use the Kimber-Martin-Ryskin prescription for unintegrated quark and gluon distribution functions, with the Martin-Roberts-Stirling-Thorne collinear parton densities for a proton as input.