The Isolated Photon Cross Section in p pbar Collisions at sqrt(s) = 1.8 TeV

TL;DR

This paper presents a new measurement of the isolated photon production cross section in proton-antiproton collisions at 1.8 TeV, comparing results with QCD predictions and analyzing background contributions.

Contribution

It provides the first detailed measurement of the isolated photon cross section at Tevatron energies, including background estimation and comparison with NLO QCD calculations.

Findings

Measured cross section agrees with NLO QCD for ET > 36 GeV.

Background from jet fragmentation was effectively estimated using calorimeter shower shapes.

Data sample of 107.6 pb-1 was used for analysis.

Abstract

We report a new measurement of the cross section for the production of isolated photons, with transverse energies (ET) above 10 GeV and pseudorapidities |eta| < 2.5, in p pbar collisions at sqrt{s} = 1.8 TeV. The results are based on a data sample of 107.6 pb-1 recorded during 1992--1995 with the D0 detector at the Fermilab Tevatron collider. The background, predominantly from jets which fragment to neutral mesons, was estimated using the longitudinal shower shape of photon candidates in the calorimeter. The measured cross section is in good agreement with the next-to-leading order (NLO) QCD calculation for ET > 36 GeV.