Observation of Isolated High-ET Photons in Photoproduction at HERA: ZEUS Collaboration

ZEUS Collaboration

Research output: Contribution to journalArticlepeer-review

Abstract

Events containing an isolated prompt photon with high transverse energy, together with a balancing jet, have been observed for the first time in photoproduction at HERA. The data were taken with the ZEUS detector, in a γp centre of mass energy range 120–250 GeV. The fraction of the incoming photon energy participating in the production of the prompt photon and the jet, xγ, shows a strong peak near unity, consistent with LO QCD Monte Carlo predictions. In the transverse energy and pseudorapidity range 5 ≤ ETγ < 10 GeV, −0.7 ≤ ηγ < 0.8, ETjet ≥ 5 GeV, and −1.5 ≤ ηjet ≤ 1.8, with xγOBS > 0.8, the measured cross section is 15.3 ± 3.8 ± 1.8 pb, in good agreement with a recent NLO calculation.
Original languageAmerican English
Pages (from-to)201-216
JournalPhysics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
Volume413
Issue number1-2
DOIs
StatePublished - Nov 6 1997

Disciplines

  • Physics

Cite this