Diffractive dijet photoproduction in ep collisions at HERA


Aaron F., Alexa C., Andreev V., Backovic S., Baghdasaryan A., Barrelet E., ...More

European Physical Journal C, vol.70, no.1, pp.15-37, 2010 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 70 Issue: 1
  • Publication Date: 2010
  • Doi Number: 10.1140/epjc/s10052-010-1448-6
  • Journal Name: European Physical Journal C
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.15-37
  • Yıldız Technical University Affiliated: No

Abstract

Measurements are presented of single and double-differential dijet cross sections in diffractive photoproduction based on a data sample with an integrated luminosity of 47 pb-1. The events are of the type ep→eXY, where the hadronic system X contains at least two jets and is separated by a large rapidity gap from the system Y, which consists of a leading proton or low-mass proton excitation. The dijet cross sections are compared with QCD calculations at next-to-leading order and with a Monte Carlo model based on leading order matrix elements with parton showers. The measured cross sections are smaller than those obtained from the next-to-leading order calculations by a factor of about 0.6. This suppression factor has no significant dependence on the fraction xγ of the photon four-momentum entering the hard subprocess. Ratios of the diffractive to the inclusive dijet cross sections are measured for the first time and are compared with Monte Carlo models. © 2010 The Author(s).