相关论文: Hard Photoproduction by Colour Singlet Exchange at…
Diffractive deep inelastic scattering at HERA and diffractive W and jet production at the Tevatron are well described by soft colour exchange models. Their essence is the variation of colour string-field topologies giving both gap and…
We investigate the production of a quark-antiquark pair in diffractive photon- proton scattering, approximating soft pomeron exchange by the exchange of two nonperturbative gluons. In deep inelastic scattering at HERA, events with two jets…
The production of jets is studied in deep-inelastic ep scattering at large negative four momentum transfer squared 150<Q^2<15000 GeV^2 using HERA data taken in 1999-2007, corresponding to an integrated luminosity of 395 pb^-1. Inclusive…
The energy dependence of the total photon-proton cross-section is determined from data collected with the ZEUS detector at HERA with two different proton beam energies.
At the electron-proton collider HERA the inclusive $D^{*\pm}$ meson photoproduction cross section has been measured with the H1 detector in two different, but partly overlapping, kinematical regions. For the first, where $<W_{\gamma p}>…
Dijet angular distributions of photoproduction events in which a $D^{*\pm}$ meson is produced in association with one of two energetic jets have been measured with the ZEUS detector at HERA, using an integrated luminosity of 120 pb$^{-1}$.…
We present a new mechanism for the creation of large rapidity gaps in DIS events at HERA. Soft colour interactions between perturbatively produced partons and colour-charges in the proton remnant, modifies the colour structure for…
Event shapes and jet shapes in neutral current deep inelastic scattering and photoproduction are studied with the H1 and ZEUS detectors at HERA. The measurements are compared to next-to-leading-order QCD calculations and Monte Carlo models.…
Highlights selected from recent measurements of colour-singlet exchange processes at HERA are summarised. Particular emphasis is placed on energy and momentum transfer dependences and the decomposition of the data into an expansion in Regge…
Multi-electron and multi-muon production at high transverse momentum is measured in $ep$ scattering at HERA. Previous published analyses are extended, combining new HERA II data taken in 2003-2004 with previous HERA I data sample. In…
A search for events containing an isolated electron or muon and missing transverse momentum produced in ep collisions is performed with the H1 and ZEUS detectors at HERA. The data were taken in the period 1994-2007 and correspond to an…
Advances in knowledge of the structure of the photon and tests of perturbative QCD have been made using the increased luminosity with the ZEUS detector at HERA. Events with a low photon virtuality and two high transverse energy jets have…
The expectations for and the measurements of transverse energy flows, single particle p_T spectra, and the rate of forward jets in deep inelastic ep events from the H1 and ZEUS experiments at HERA are reported and discussed. It is shown…
Beauty production in deep inelastic scattering with events in which a muon and a jet are observed in the final state has been measured with the ZEUS detector at HERA using an integrated luminosity of 114 pb^-1. The fraction of events with…
Measurements of cross sections for events with charm and beauty jets in deep inelastic scattering at HERA are presented. Events with jets of transverse energy E_T^jet > 6 GeV and pseudorapidity -1.0 < eta^jet < 1.5 in the laboratory frame…
The charm fragmentation function has been measured in D* photoproduction with the ZEUS detector at HERA using an integrated luminosity of 120 pb-1. The fragmentation function is measured versus z = (E+p_parallel){D*}/2E{jet}, where E is the…
Processes leading to a final state with at least two high transverse momentum leptons (electrons or muons) are studied using the full ep data sample collected by the H1 experiment at HERA. The data correspond to an integrated luminosity of…
In diffractive jet production, two high energy hadrons A and B collide and produce high transverse momentum jets, while hadron A is diffractively scattered. Ingelman and Schlein predicted this phenomenon. In their model, part of the…
Between 1992 and 2007, the HERA accelerator provided $ep$ collisions at center of mass energies beyond $300 \ {\rm GeV}$ at the interaction points of the H1 and ZEUS experiments. Interesting results to emerge relate to the newly accessed…
We present next-to-leading order calculations of one- and two-jet production in eP collisions at HERA for photon virtualities in the range 1<Q^2<100 GeV^2. Soft and collinear singularities are extracted using the phase space slicing method.…