569 research outputs found
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
Universality for 2D Wedge Wetting
We study 2D wedge wetting using a continuum interfacial Hamiltonian model
which is solved by transfer-matrix methods. For arbitrary binding potentials,
we are able to exactly calculate the wedge free-energy and interface height
distribution function and, thus, can completely classify all types of critical
behaviour. We show that critical filling is characterized by strongly universal
fluctuation dominated critical exponents, whilst complete filling is determined
by the geometry rather than fluctuation effects. Related phenomena for
interface depinning from defect lines in the bulk are also considered.Comment: 4 pages, 1 figur
Quark model predictions for the SU(6)-breaking ratio of the proton momentum distributions
The ratio between the anomalous magnetic moments of proton and neutron has
been recently parametrized by the ratio of proton momentum fractions
. This ratio is evaluated using different constituent quark
models, starting from the CQM density distributions and calculating the next-to
leading order distributions. We show that this momentum fractions
ratio is a sensitive test for SU(6)-breaking effects and
therefore it is useful to distinguish among different CQMs. We investigate also
the possibility of getting constraints on the formulation of quark structure
models.Comment: 12 pages, 3 figure
Reduction of Hospital Physicians' Workflow Interruptions: A Controlled Unit-Based Intervention Study
The Effect of Amphotericin B on the Water and Nonelectrolyte Permeability of Thin Lipid Membranes
Ethnic In-Group Favoritism Among Minority and Majority Groups: Testing the Self-Esteem Hypothesis Among Preadolescents
The self-esteem hypothesis in intergroup relations, as proposed by social identity
theory (SIT), states that successful intergroup discrimination enhances momentary
collective self-esteem. This hypothesis is a source of continuing controversy. Furthermore,
although SIT is increasingly used to account for childrenâs group attitudes,
few studies have examined the hypothesis among children. In addition, the
hypothesisâs generality makes it important to study among children from different
ethnic groups. The present study, conducted among Dutch and Turkish preadolescents,
examined momentary collective self-feelings as a consequence of ethnic group
evaluations. The results tended to support the self-esteem hypothesis. In-group
favoritism was found to have a self-enhancing effect among participants high in
ethnic identification. This result was found for ethnic majority (Dutch) and minority
(Turkish) participants.
Nonperturbative versus perturbative effects in generalized parton distributions
Generalized parton distributions (GPDs) are studied at the hadronic
(nonperturbative) scale within different assumptions based on a relativistic
constituent quark model. In particular, by means of a meson-cloud model we
investigate the role of nonperturbative antiquark degrees of freedom and the
valence quark contribution. A QCD evolution of the obtained GPDs is used to add
perturbative effects and to investigate the GPDs' sensitivity to the
nonperturbative ingredients of the calculation at larger (experimental) scale.Comment: 17 pages, 10 figures; submitted to Phys. Rev.
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