Diffractive jet production in deep-inelastic $e^+p$ collisions at HERA

The H1 Collaboration C. Adloff; et al.

doi:doi:10.1007/s100520100634

EPJ

Diffractive jet production in deep-inelastic e⁺p collisions at HERA

The H1 Collaboration C. Adloff and et al.

(Received: 21 December 2000 / Published online: 6 April 2001 -© Springer-Verlag 2001)

Abstract
A measurement is presented of dijet and 3-jet cross sections in low-|t| diffractive deep-inelastic scattering interactions of the type $ep \rightarrow eXY$ , where the system X is separated by a large rapidity gap from a low-mass baryonic system Y. Data taken with the H1 detector at HERA, corresponding to an integrated luminosity of $18.0 \rm pb^{-1}$ , are used to measure hadron level single and double differential cross sections for $4< Q^2< 80 \rm\ GeV^2$ , $x_\mathbb{P} < 0.05$ and $p_{T,jet}> 4 \rm GeV$ . The energy flow not attributed to jets is also investigated. The measurements are consistent with a factorising diffractive exchange with trajectory intercept close to 1.2 and tightly constrain the dominating diffractive gluon distribution. Viewed in terms of the diffractive scattering of partonic fluctuations of the photon, the data require the dominance of $q\overline{q}g$ over $q\overline{q}$ states. Soft colour neutralisation models in their present form cannot simultaneously reproduce the shapes and the normalisations of the differential cross sections. Models based on 2-gluon exchange are able to reproduce the shapes of the cross sections at low $x_\mathbb{P}$ values.

Società Italiana di Fisica, Springer-Verlag 2001