43 research outputs found
Time-odd mean fields in the rotating frame: microscopic nature of nuclear magnetism
The microscopic role of nuclear magnetism in rotating frame is investigated
for the first time in the framework of the cranked relativistic mean field
theory. It is shown that nuclear magnetism modifies the expectation values of
single-particle spin, orbital and total angular momenta along the rotational
axis effectively creating additional angular momentum. This effect leads to the
increase of kinematic and dynamic moments of inertia at given rotational
frequency and has an impact on effective alignments.Comment: 16 pages, 4 figures, submitted to Physical Review
K* nucleon hyperon form factors and nucleon strangeness
A crucial input for recent meson hyperon cloud model estimates of the nucleon
matrix element of the strangeness current are the nucleon-hyperon-K* (NYK*)
form factors which regularize some of the arising loops. Prompted by new and
forthcoming information on these form factors from hyperon-nucleon potential
models, we analyze the dependence of the loop model results for the
strange-quark observables on the NYK* form factors and couplings. We find, in
particular, that the now generally favored soft N-Lambda-K* form factors can
reduce the magnitude of the K* contributions in such models by more than an
order of magnitude, compared to previous results with hard form factors. We
also discuss some general implications of our results for hadronic loop models.Comment: 9 pages, 8 figures, new co-author, discussion extended to the
momentum dependence of the strange vector form factor
Hadronization of a Quark-Gluon Plasma in the Chromodielectric Model
We have carried out simulations of the hadronization of a hot, ideal but
effectively massive quark-gluon gas into color neutral clusters in the
framework of the semi-classical SU(3) chromodielectric model. We have studied
the possible quark-gluon compositions of clusters as well as the final mass
distribution and spectra, aiming to obtain an insight into relations between
hadronic spectral properties and the confinement mechanism in this model.Comment: 34 pages, 37 figure
Polarization observables in the reaction
We study the reaction slightly above the threshold within an
extended one-boson exchange model which also accounts for knock-out. It
is shown that polarization observables, like the beam-target asymmetry, are
sensible quantities for identifying a admixture in the nucleon wave
function on the few per cent level.Comment: 11 LaTeX pages including 4 ps figure
The role of the pion cloud in the interpretation of the valence light-cone wavefunction of the nucleon
The pion cloud renormalises the light-cone wavefunction of the nucleon which
is measured in hard, exclusive photon-nucleon reactions. We discuss the leading
twist contributions to high-energy exclusive reactions taking into account both
the pion cloud and perturbative QCD physics. The nucleon's electromagnetic
form-factor at high is proportional to the bare nucleon probability
and the cross-sections for hard (real at large angle or deeply virtual) Compton
scattering are proportional to . Our present knowledge of the pion-nucleon
system is consistent with . If we apply just perturbative QCD
to extract a light-cone wavefunction directly from these hard exclusive
cross-sections, then the light-cone wavefunction that we extract measures the
three valence quarks partially screened by the pion cloud of the nucleon. We
discuss how this pion cloud renormalisation effect might be understood at the
quark level in terms of the (in-)stability of the perturbative Dirac vacuum in
low energy QCD.Comment: Expanded Discussion of Phenomenology and Spin Physic
Design and analysis of cross vaults along history
The history of cross vaults began almost 2,000 years ago with a widespread use during the Middle Ages and Renaissance, becoming nowadays one of the most diffused and fascinating structural typologies of the European building cultural heritage. However, conversely to the undeniable excellence achieved by the ancient masons, the structural behavior of these elements is still at the center of the scientific debate. In this regard, with the aim of reviewing the knowledge on this subject as a concise and valuable support for researchers involved in conservation of historical buildings, with a focus on design rules and structural analysis, the present study firstly introduces the cross vaults from a historical perspective, by describing the evolution of the main geometrical shapes together with basic practical rules used to size them. Then, the article deals with the subsequent advancements in structural analysis methods of vaults, until the development of modern limit analysis.This work was partially carried out under the program "Dipartimento di Protezione Civile - Consorzio RELUIS", signed on 2013-12-27.info:eu-repo/semantics/publishedVersio
Recent progress and perspectives of space electric propulsion systems based on smart nanomaterials
Miniaturized spacecraft built from advanced nanomaterials are poised for unmanned space exploration. In this review, the authors examine the integration of nanotechnology in electric propulsion systems and propose the concept of self-healing and adaptive thrusters
Suppression of CMV Infection with Letermovir in a Kidney Transplant Patient
Infection with cytomegalovirus (CMV) with resistance to ganciclovir (GCV) is a therapeutic challenge in kidney transplant patients, because standard treatment options are nephrotoxic. We report the case of a kidney transplant recipient with GCV-resistant CMV disease, in whom letermovir, a novel inhibitor of CMV packaging, was administered off-label and prevented a relapse of disease once the CMV load was decreased by cidofovir. Furthermore, we observed significant drug interactions between letermovir and tacrolimus