Related papers: A study on Delta u and Delta d in charged current …
Recent results on subjet distributions from ZEUS are presented. The measured normalised cross sections were used to study the pattern of parton radiation. The comparison of the measurements with leading-logarithm parton-shower Monte Carlo…
We investigate the possibility to identify photon-gluon fusion (PGF) events in polarised deep inelastic ep scattering, assuming the kinematics of the HERA collider, by a pair of charged high p_t particles. In a Monte Carlo study we find…
The discovery potential of the HERA collider, with and without polarized beams, for electron-quark contact interactions in neutral current scattering is reviewed. The measurement of spin asymmetries in the polarized case could give crucial…
Triple differential dijet cross-sections in e p interactions measured with the H1 and ZEUS detectors at HERA are presented. The data are compared to Monte Carlo simulations which differ in their assumptions about photon structure and parton…
Charged current charm and D meson production is studied in detail as a means of determining the unpolarized and polarized strange sea densities at HERA. All analyses are performed in next-to-leading order QCD, including a calculation of the…
We review the current situation in polarized scattering experiments. We describe the theoretical interpretation of inclusive deep inelastic processes, the current experimental situation and perturbative analyses which extract structure…
A summary is given on the physics potential of measuring singly polarized proton--nucleon collisions using a polarized internal target in the 820 GeV HERA proton beam. This summary is based upon talks given at the 2nd Meeting on 'Possible…
The physics of polarized nucleon--nucleon collisions originating from an internal polarized target in the HERA proton beam is investigated. Based on 240 pb^-1 integrated luminosity at 40 GeV c.m. energy, statistical sensitivities are given…
Recent data obtained in ep collisions at HERA by the H1 collaboration are presented: searches for new phenomena beyond the Standard Model, measurement of the inclusive neutral and charged current cross sections and of the proton structure…
The ZEUS detector has been used to study dissociation of virtual photons in events with a leading proton, gamma^* p -> X p, in e^+p collisions at HERA. The data cover photon virtualities in two ranges, 0.03<Q^2<0.60 GeV^2 and 2<Q^2<100…
Recent progresses of the proton structure measurements and determination of parton distribution functions by $ep$ collisions at HERA are introduced.
We analyze the effects of Scalar and Vector Leptoquarks on various observables in electron (positron) - proton deep inelastic scattering. In view of the future program of the HERA collider, with a high luminosity and also with polarization,…
The azimuthal decorrelation angle between the leading jet and scattered lepton in deep inelastic scattering is studied with the ZEUS detector at HERA. The data was taken in the HERA II data-taking period and corresponds to an integrated…
The physics scope of a possible future experiment utilizing an internal polarized nucleon target in the HERA proton beam is discussed. By measuring single spin asymmetries in inclusive particle production at 820~GeV beam energy the…
We study various conceivable photoproduction reactions in a polarized ep collider mode of HERA with respect to their sensitivity to the proton's polarized gluon distribution. A special emphasis is put on the `resolved' part of the cross…
A model--independent search for deviations from the Standard Model prediction is performed using the full $e^\pm p$ data sample collected by the H1 experiment at HERA. All event topologies involving isolated electrons, photons, muons,…
Longitudinal polarisation of the lepton beam is a key ingredient to the success of the world's unique e\pmp ring collider HERA. This article aims at providing a brief introduction to the physics motivation for deep-inelastic scattering of…
A Monte Carlo simulation based on O(alpha_s) QCD matrix elements matched to parton showers shows that final-state hadrons in deep inelastic scattering (DIS) can be used to tag events with a single (anti)quark recoiled against the proton.…
The measurement and QCD analysis of neutral and charged current cross sections at HERA are presented. For the kinematic range of four-momentum transfer Q^2 between approx. 1 GeV^2 and 30000 GeV^2 and Bjorken x between 0.0013 and 0.65 the…
After fifteen years of running and a further five years of analysis, the final inclusive deep inelastic scattering cross sections from H1 and ZEUS have been published. Measurements of neutral current and charged current processes in ep…