Splitting the pomeron into two jets: a novel process at HERA

Abstract

We study a novel property of large rapidity-gap events in deep inelastic scattering at HERA: splitting the pomeron into two jets in the photon-pomeron fusion reaction ${\gamma }^{\ast }\text{Pom}\to q\bar{q}$. It gives rise to the diffraction dissociation of virtual photons into the back-to-back jets. We find that at large invariant mass $M$ of two jets, $M^2\gg Q^2$, the transverse momentum of jets comes from the intrinsic transverse momentum of gluons in the pomeron, and the photon-pomeron fusion direcly probes the diffrential gluon structure function of the proton $\partial G(x,q^2)/\partial \log q^2$ at the virtuality $q^2\sim k^2$. We present estimates for the jet production cross section, which show the process is easily measurable at HERA.

Comments: 11 pages, 4 figures on request from kph154@zam001.zam.kfa-juelich.de, Juelich preprint KFA-IKP(Th)-1994-16, 10 March 1994