Measurement of the Cross Section for Prompt Isolated Diphoton Production in p\bar p Collisions at \sqrt{s} = 1.96 TeV

TL;DR

This paper measures the cross section of prompt isolated diphoton production in proton-antiproton collisions at 1.96 TeV and compares the results with various QCD theoretical predictions, finding NLO calculations most consistent.

Contribution

It provides the first detailed measurement of diphoton production cross sections at Tevatron energies and evaluates the accuracy of different QCD models against the data.

Findings

NLO calculations reproduce most data features.

Parton shower predictions become competitive when including photon radiation.

Measured cross sections align well with NLO predictions.

Abstract

This letter reports a measurement of the cross section of prompt isolated photon pair production in p\bar p collisions at a total energy \sqrt{s} = 1.96 TeV using data of 5.36/fb integrated luminosity collected with the CDF II detector at the Fermilab Tevatron. The measured cross section, differential in basic kinematic variables, is compared with three perturbative QCD predictions, a Leading Order (LO) parton shower calculation and two Next-to-Leading Order (NLO) calculations. The NLO calculations reproduce most aspects of the data. By including photon radiation from quarks before and after hard scattering, the parton shower prediction becomes competitive with the NLO predictions.