Measurement of the isolated diphoton cross-section in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

TL;DR

This paper reports the measurement of the isolated diphoton production cross-section in proton-proton collisions at 7 TeV using the ATLAS detector, providing data to test QCD predictions and improve understanding of photon production.

Contribution

The study presents the first measurement of the diphoton cross-section at 7 TeV with the ATLAS detector, using a data-driven background estimation and comparing results to NLO QCD predictions.

Findings

Measured differential cross-sections as functions of diphoton mass, transverse momentum, and azimuthal separation.

Data agrees with next-to-leading-order QCD predictions within uncertainties.

Provides valuable data for testing QCD models and background estimates for new physics searches.

Abstract

The ATLAS experiment has measured the production cross-section of events with two isolated photons in the final state, in proton-proton collisions at sqrt(s) = 7 TeV. The full data set acquired in 2010 is used, corresponding to an integrated luminosity of 37 pb^-1. The background, consisting of hadronic jets and isolated electrons, is estimated with fully data-driven techniques and subtracted. The differential cross-sections, as functions of the di-photon mass, total transverse momentum and azimuthal separation, are presented and compared to the predictions of next-to-leading-order QCD.