Diffractive Interactions

The general framework of diffractive deep inelastic scattering is introduced and reports given in the session on diffractive interactions at the International Workshop on Deep-Inelastic Scattering and Related Phenomena, Rome, April 1996, are presented.Comment: LaTeX with procl.sty, 20 pages. To appear in the Proceedings of the International Workshop on Deep Inelastic Scattering and Related Phenomena, Roma, Italy, April 199

Diffraction at HERA and Prospects with H1

In the context of the tremendous progress achieved at HERA in diffraction and the need for a new level of statistical and systematic precision, the new very large acceptance forward spectrometer planned by H1 (VFPS) is presented and the physics issues are stressed

On the possibility of measuring FL(x,Q2)F_L(x,Q^2) at HERA using radiative events

It is shown that a significant measurement of the longitudinal structure function $F_L(x,Q^2)$ can be performed at HERA, for $Q^2 = 2 GeV^2$ and $Q^2 = 5 GeV^2$ and for x around $10^{-4}$, using radiative events with hard photon emission collinear to the incident lepton beam, under the present running conditions and with an integrated luminosity of 10 $pb^{-1}$. The influence of experimental conditions is discussed.Comment: 12 pages (6 figures

Easy as πo\pi^o: On the Interpretation of Recent Electroproduction Results

Exclusive $\pi^o$ electroproduction from nucleons was first suggested by Ahmad, Goldstein and Liuti for extracting from experimental data the tensor charge, transversity and other quantities related to chiral odd combinations of generalized parton distributions. We now explain the details of the process: {\it i)} the connection between the helicity description and the cartesian basis; {\it ii)} the dependence on the momentum transfer squared, $Q^2$, and {\it iii)} the angular momentum, parity, and charge conjugation constraints ($J^{PC}$ quantum numbers).Comment: 15 pages, 2 figures, some changes in formalism, and text. Introduced section title

Charged rho meson production in neutrino-induced reactions at E_nu = 10 GeV

The neutrinoproduction of charged $\rho$ mesons on nuclei and nucleons is investigated for the first time at moderate energies ($\approx$ 10 GeV), using the date obtained with SKAT bubble chamber. No strong nuclear effects are observed in $\rho^+$ and $\rho^-$ production. The fractions of charged and neutral pions originating from $\rho$ decays are obtained and compared with higher energy data. From analysis of the obtained and available data on $\rho^+$ and $K^{*+}$(892) neutrinoproduction, the strangeness suppression factor in the quark string fragmentation is extracted: $\lambda_s = 0.18\pm0.03$. Estimations are obtained for cross sections of quasiexclusive single $\rho^+$ and coherent $\rho^+$ neutrinoproduction on nuclei. The estimated coherent cross section $\sigma_{\rho^+}^{coh}$ = (0.29$\pm0.16)\cdot 10^{-38}$ cm$^2$ is compatible with theoretical predictions.Comment: 7 pages, 6 figure

Shadowing in neutrino deep inelastic scattering and the determination of the strange quark distribution

We discuss shadowing corrections to the structure function $F_2$ in neutrino deep-inelastic scattering on heavy nuclear targets. In particular, we examine the role played by shadowing in the comparison of the structure functions $F_2$ measured in neutrino and muon deep inelastic scattering. The importance of shadowing corrections in the determination of the strange quark distributions is explained.Comment: 22 pages, 7 figure

Nuclear Attenuation of Fast Hadrons Produced in Charged-Current Neutrino and Antineutrino Interactions in Neon

The production of hadrons in charged-current (anti)neutrino interactions is studied with the bubble chamber BEBC exposed ot the CERN (anti)neutrino wide-band beam. Fast-hadron production in a neon target is found to be attennuated as compared to that in a hydrogen target. This feature is discussed within the theoretical models based on the idea of a hadron formation length. The experimental results favour the `constituent' over the `yo-yo' length concept, and suggest a quark cross-section in the order of 3mb.Comment: 14 pages + 7 figures, ps fil