Hadronic nal states are analyzed with the ZEUS detector for deep inelastic di ractive scattering ep ! eXp, in which the virtual photon dissociates into a hadronic nal state of mass 4 < MX < 35 GeV and the scattered proton, carrying more than 95% of the initial proton momentum, is detected in the Leading Proton Spectrometer. The event shape variables thrust and sphericity are studied as a functi...

The nucleon wave function may contain a significant component of s̄s pairs, according to several measurements including the π-nucleon σ term, charm production and polarization effects in deep-inelastic scattering. In addition, there are excesses of φ production in LEAR and other experiments, above predictions based the naive Okubo-Zweig-Iizuka rule, that may be explained if the nucleon wave func...

In the case of the gluon-fusion process in deep-inelastic leptoproduction, I explicitly show how to incorporate NLO corrections in a Monte-Carlo event generator by a subtraction method. I calculate the parton densities to be used by the event generator in terms of MS densities. The method is generalizable. A particular motivation for treating the gluon-fusion process is to treat diffractive dee...

We give a brief overview of the status of perturbative QCD calculations for deep-inelastic scattering. The radiative corrections to the Wilson coefficients are generally available to next-to-next-to-leading order in QCD and we address the accuracy of the strong coupling constant, the parton distributions of the nucleon and the heavy quark masses which is required for precision predictions. We a...

The generalized Crewther relation relates the cross section ratio R = σ(e + e − → hadrons)/σ(e + e − → µ + µ −) in e + e − annihilation with the Bjorken sum rule or the Gross-Llewellyn Smith sum rule in deep inelastic scattering and provides a fundamental connection for observables in Quantum Chromodynamics (QCD) without scale or scheme ambiguities. The ratio R can be measured at the upgrated B...

We analyze nuclear effects in the deep inelastic scattering on deuteron in the framework of the covariant approach. It is shown that this approach gives us the way to investigate the role of relativistic effects in the deep inelastic scattering (DIS) on deuteron, such as the relativistic kinematics and the off-mass-shell behavior of the Compton amplitude of nucleon in the consistent manner. We ...

Initial-state and final-state interactions which are conventionally neglected in the parton model, have a profound effect in QCD hard-scattering reactions. The effects, which arise from gluon exchange between the active and spectator quarks, cause leading-twist single-spin asymmetries, diffractive deep inelastic scattering, diffractive hard hadronic reactions, and the breakdown of the Lam-Tung ...

We analyse recent data on the production of forward neutrons in deep inelastic scattering at HERA in the framework of a perturbative QCD description for semi-inclusive processes, which includes fracture functions. In the most naive quark-parton model picture, the semi-inclusive cross section for the production of a hadron h from the deep inelastic scattering of charged leptons is usually taken ...

Abstract Transverse polarization in the Hyperon (Λ) production in the unpolarized deep inelastic scattering and pp collisions is studied in the twist-three approach, considering the contribution from the quark-gluon-antiquark correlation distribution in nucleon. We further compare our results for deep inelastic scattering to a transverse momentum dependent factorization approach, and find consi...