The production of hard di-jet events in photoproduction at HERA is dominate
d by resolved photon processes in which a parton in the photon with momentu
m fraction x(gamma) is scattered from a parton in the proton. These process
es are sensitive to the quark and gluon content of the photon. The differen
tial di-jet cross-section d sigma/dlog(x(gamma)) is presented here, measure
d 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, E-Y,E-jet > 6 GeV, the effectiv
e parton density f(gamma,eff)(x(gamma)) = [q(x(gamma)) + (q) over bar(x(gam
ma)) + 9/4 g(x(gamma))] in the photon in leading order QCD is measured down
to x(gamma) = 0.05 from which the gluon density in the photon is derived.
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