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

Abstract

A measurement is presented of dijet and 3-jet cross sections in low-|t| diffractive deepinelastic scattering interactions of the type ep → 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 pb −1 , are used to measure hadron level single and double differential cross sections for 4 < Q 2 < 80 GeV 2 , x IP < 0.05 and p T,jet > 4 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 qqg over qq 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 IP values.

Factorization scheme and scale dependence in diffractive dijet production at lowQ2

“…The asymmetric cuts for the transverse momenta of the two jets are required for infrared stable comparisons with the NLO calculations [17]. The original H1 analysis actually used a symmetric cut of 4 GeV on the transverse momenta of both jets [18]. The data have, however, been reanalysed for asymmetric cuts [14].…”

Impact factor for high-energy two and three jets diffractive production

“…The results we obtained, in coordinate space, are very suitable for phenomenological studies of diffractive processes since they allow for the implementation of saturation models, when considering the color-singlet channel. The measurement of dijet production in DDIS was recently performed [50], and a precise comparison of dijet versus triple-jet production, which has not been performed yet at HERA [51], would be very useful to get a deeper understanding of the QCD mechanism underlying diffraction. Such a ratio would provide an observable possibly more independent of any saturation effect.…”

Diffractive dijet production and Wigner distributions from the color glass condensate

“…This is because of non-cancellation of soft interactions ('Glauber' or 'Coulomb' gluons) between the incoming hadrons and/or their remnants in the initial and final state. Our main focus in this work is diffractive jet production, previously studied at HERA [47][48][49][50][51], where large differences between next-to-leading order calculations and experimental data from ZEUS [52] and H1 [53][54][55][56][57][58] have been attributed to factorization breaking [59][60][61] 1 .…”