Author/Authors :
Q2) Original Research Article
Pages 471-502
H1 Collaboration، نويسنده , , J. C. Adloff، نويسنده , , A. V. Andreev، نويسنده , , B. Andrieu، نويسنده , , V. Arkadov، نويسنده , , A. Astvatsatourov، نويسنده , , I. Ayyaz، نويسنده , , A. Babaev and NRMI Investigators، نويسنده , , Matthias J. Bahr، نويسنده , , P. Baranov، نويسنده , , E. Barrelet، نويسنده , , W. Bartel، نويسنده , , U. Bassler، نويسنده , , P. Bate، نويسنده , , A. Beglarian، نويسنده , , O. Behnke، نويسنده , , C. Beier، نويسنده , , V. A. Belousov، نويسنده , , T. Benisch، نويسنده , , Ch. Berger، نويسنده , , et al.، نويسنده ,
Abstract :
The production of hard di-jet events in photoproduction at HERA is dominated by resolved photon processes in which a parton in the photon with momentum fraction xγ is scattered from a parton in the proton. These processes are sensitive to the quark and gluon content of the photon. The differential di-jet cross-section dσ/dlog(xγ) is presented here, measured in tagged photoproduction at HERA using data taken with the H1 detector, corresponding to an integrated luminosity of 7.2 pb−1. Using a restricted data sample at high transverse jet energy, ET,jet>6 GeV, the effective parton density fγ,eff(xγ)=q(xγ)+q̄(xγ)+9/4 g(xγ) in the photon in leading order QCD is measured down to xγ= 0.05 from which the gluon density in the photon is derived.
