Measurement of Dijet Cross Sections in Photoproduction at HERA

TL;DR

This paper measures dijet cross sections in photoproduction at HERA, comparing experimental data with next-to-leading order QCD predictions to test the theory's accuracy across various kinematic ranges.

Contribution

It provides the first detailed measurement of dijet cross sections in photoproduction at HERA using the inclusive k_T algorithm with high-energy jets, and compares results with advanced QCD predictions.

Findings

Data agree with NLO QCD predictions across a wide kinematic range.

Jets are selected with a minimum transverse energy of 25 GeV.

The measurements constrain photon and proton parton densities.

Abstract

Dijet cross sections as functions of several jet observables are measured in photoproduction using the H1 detector at HERA. The data sample comprises e^+p data with an integrated luminosity of 34.9 pb^(-1). Jets are selected using the inclusive k_T algorithm with a minimum transverse energy of 25 GeV for the leading jet. The phase space covers longitudinal proton momentum fraction x_p and photon longitudinal momentum fraction x_gamma in the ranges 0.05<x_p<0.6 and 0.1<x_gamma<1. The predictions of next-to-leading order perturbative QCD, including recent photon and proton parton densities, are found to be compatible with the data in a wide kinematical range.