Note on Shadowing and Diffraction in Deep-Inelastic Lepton Scattering

We discuss the close relation between shadowing in deep-inelastic lepton-nucleus scattering and diffractive photo- and leptoproduction of hadrons from free nucleons. We show that the magnitude of nuclear shadowing at small Bjorken-x, as measured by the E665 and NMC collaborations, is directly related to HERA data on the amount of diffraction in the scattering from free nucleons.Comment: 6 pages, Latex, to be published in Eur. Phys. J.

Diffractive rho^0 photo- and leptoproduction at high energies

We discuss the elastic photo- and leptoproduction of rho^0-mesons from nucleons at Q^2 < 1 GeV^2 as studied in recent experiments at HERA and FNAL. We find that the mass distribution of the measured \pi^+\pi^- pairs is determined to a large extent by the two-pion contribution to the photon spectral function as given by the pion form factor. With rising Q^2 the rate of diffractive events decreases and the \pi^+\pi^- mass distribution approaches a symmetric shape.Comment: 7 pages LaTeX, 3 figures, to appear in Phys.Lett.

Coherent Vector Meson Production from Deuterons

In this paper we discuss coherent photo- and leptoproduction of vector mesons from deuterons at intermediate (virtual) photon energies, 3 < nu < 30 GeV. We consider the scattering from unpolarized and polarized targets as well as processes where the polarization of the recoil deuteron is measured. Our main motivation results from the need for a quantitative analysis of the space-time structure of photon-induced processes. In this respect we suggest several possibilities to explore the characteristic longitudinal interaction length in coherent vector meson production. Furthermore, we outline methods for an investigation of color coherence effects. In addition to the presentation of benchmark values for the maximal possible color coherence effect in various kinematic regions, we illustrate the anticipated phenomena within the color diffusion model. Finally we recall that the determination of vector meson-nucleon cross sections is not a closed issue. Besides being not known to a satisfying accuracy, they can be used to determine the strength of the D-state in low mass vector mesons.Comment: LaTeX, 22 page

Stakeholder Perspectives: How Participation in a Work-Based Learning Program Affects Perceptions

The concept of disability and how it is perceived varies based on one’s own understanding, prior experiences, position, and interactions with others. By adding the variable of employment into the equation, perceptions surrounding disability can have a significant impact on the disabled community. The amount of significance corresponds directly with the level or degree of one’s disability and other identities. Currently, the separation between employment rates for disabled adults and their non-disabled counterparts is vast (Sametz, 2017). The purpose of this study is to examine some variables that affect employment outcomes for youth with low-incidence disabilities. Guided by theoretical frameworks of Disability Studies (DS) and Disability Studies and Critical Race Theory (DisCrit) and drawing on a conceptual framework of phenomenology, this qualitative study utilizes a focus group, interviews, survey, and researcher field notes to elicit the perceptions of those involved in a work-based learning program (WBL). Initial coding and an inter-rater reliability check identified fourteen codes. Three themes emerged during second round coding. Results are indicative of the importance of work preparation programs for all stakeholders, as the concepts of work and disability are perceived in relation to our position, shared experiences, and sense of belonging

NLO Corrections to Deeply-Virtual Compton Scattering

We have calculated the NLO corrections to the twist-2 part of the deeply-virtual Compton scattering amplitude. Our results for the transverse and antisymmetric parts agree with recent calculations by Ji and Osborne and by Belitsky and M\"uller. In addition we present NLO results for the longitudinal part of the amplitude.Comment: 8 pages, Latex. Error in polarised gluonic coefficient in Eq.(8) correcte

Sensitivity of DynaWhirlpool hydrocyclone operation to applied back-pressure

3noThe two-phase, air–water flow pattern in a DynaWhirlpool centrifugal separator is investigated using time-dependent, three-dimensional numerical simulation. The air–water interface is captured by the Volume-Of-Fluid approach,while the unresolved turbulence fluctuations are modeled via a second-order differential-stress turbulence model. Among the different operating variables, the back-pressure at the sink outlet affects significantly the flow within the cyclone. The modifications experienced by the flow field as the back-pressure is increased are documented and interpreted. The variation of relevant operating variables is also reported, as the split ratio and the Euler number characterizing the device. It is verified that for large values of the back-pressure the water flow through the sink is hindered and the air core disappears. The flow pattern is moderately altered when the cyclone is fed with a non-Newtonian fluid with the same viscosity as a real water/magnetite dense medium.partially_openopenPiller, M.; Schena, G.; Belardi, G.Piller, Marzio; Schena, Gianni; Belardi, G