Three- and four-jet final states in photoproduction at HERA
Abstract
Three- and four-jet final states have been measured in photoproduction at HERA using the ZEUS detector with an integrated luminosity of 121 pb^-1. The results are presented for jets with transverse energy E_T^jet>6 GeV and pseudorapidity |eta^jet|<2.4, in the kinematic region given by the virtuality of the photon Q^2<1 GeV^2 and the inelasticity 0.2<y<0.85 and in two mass regions defined as 25<M_nj<50 GeV and M_nj>50 GeV, where M_nj is the invariant mass of the n-jet system. The four-jet photoproduction cross section has been measured for the first time and represents the highest-order process studied at HERA. Both the three- and four-jet cross sections have been compared with leading-logarithmic parton-shower Monte Carlo models, with and without multi-parton interactions. The three-jet cross sections have been compared to an order(alpha alpha_s^2) perturbative QCD calculation.
Cite
@article{arxiv.0707.3749,
title = {Three- and four-jet final states in photoproduction at HERA},
author = {ZEUS Collaboration and S. Chekanov},
journal= {arXiv preprint arXiv:0707.3749},
year = {2008}
}
Comments
50 pages, 15 figures, 22 tables, submitted to Nucl. Phys. B