15 research outputs found
Neutrino cross sections and nuclear structure
The effects of the theoretical uncertainties in the description of
neutrino-nucleus cross sections for supernova neutrino energies are
investigated.Comment: Contribution to NOW 2008, Conca Specchiulla (Otranto, Italy),
September 6-13 200
Tensor and tensor-isospin terms in the effective Gogny interaction
We discuss the need of including tensor terms in the effective Gogny
interaction used in mean-field calculations. We show in one illustrative case
that, with the usual tensor term that is employed in the Skyrme interaction
(and that allows us to separate the like-nucleon and the neutron-proton tensor
contributions), we can describe the evolution of the N=28 neutron gap in
calcium isotopes. We propose to include a tensor and a tensor-isospin term in
finite-range interactions of Gogny type. The parameters of the two tensor terms
allow us to treat separately the like-nucleon and the neutron-proton
contributions. Two parameterizations of the tensor terms have been chosen to
reproduce different neutron single-particle properties in the 48Ca nucleus and
the energy of the first 0- state in the 16O nucleus. By employing these two
parameterizations we analyze the evolution of the N=14, 28, and 90 neutron
energy gaps in oxygen, calcium and tin isotopes, respectively. We show that the
combination of the parameters governing the like-nucleon contribution is
crucial to correctly reproduce the experimental (where available) or
shell-model trends for the evolution of the three neutron gaps under study.Comment: 20 pages, 6 figures. Accepted for publication in Physical Review
Effective tensor forces and neutron rich nuclei
We study the effects of the tensor term of the effective nucleon-nucleon
interaction on nuclear excited states. Our investigation has been conducted by
using a self-consistent Random Phase Approximation approach. We investigate
various nuclei in different regions of the isotopes chart. Results for a set of
calcium isotopes are shown.Comment: 4 pages, 4 figures, 1 table Proc. 10th International Spring Seminar
on Nuclear Physics New Quests in Nuclear Structure, Vietri Sul Mare, May
21-25, 201
Continuum Random Phase Approximation with finite-range interactions
We rewrite the Random Phase Approximation secular equations in a form which allows the treatment of the continuum part of the single-particle spectrum without approximations. Within this formalism finite-range interactions can be used without restrictions. We present some results, obtained with Gogny interactions, where the role of the continuum is relevant
Quasifree (e,e'p) reactions on nuclei with neutron excess
We study the evolution of the (e,e'p) cross section on nuclei with increasing
asymmetry between the number of neutrons and protons. The calculations are done
within the framework of the distorted-wave impulse approximation, by adopting
nonrelativistic and relativistic models. We compare the results obtained with
three different approaches based on the mean-field description for the proton
bound state wave function. In the nonrelativistic model phenomenological
Woods-Saxon and Hartree-Fock wave functions are used, in the relativistic model
the wave functions are solutions of Dirac-Hartree equations. The models are
first tested against experimental data on O, Ca, and Ca
nuclei, and then they are applied to calculate \eep cross sections for a set of
spherical calcium and oxygen isotopes. From the comparison of the results
obtained for the various isotopes we can infer information about the dependence
of the various ingredients of the models on the neutron to proton asymmetry.Comment: 20 pages, 8 figures, version accepted in Physical Review
Feasibility and reliability of a questionnaire for evaluation of the exposure to indoor and outdoor air pollutants, diet and physical activity in 6-8-year-old children.
INTRODUCTION:
The MAPEC-Life project aims to study the biological effects of early exposure to air pollutants on the oral mucosa cells of school-age children in five Italian cities. A questionnaire was created to evaluate the association between outdoor and indoor airborne pollutants, lifestyle, diet and biomarker effects. The feasibility and reliability of the questionnaire were evaluated.
METHODS:
A questionnaire was drawn up to be filled in by the parents of 6-8-year-old children. It consisted of 148 questions on the children's health, physical activity, environmental exposures and the frequency of food consumption at the main meals. First we conducted a questionnaire feasibility study involving 53 volunteer parents. We then performed a reliability study by administering the questionnaire to a further 156 parents and again one month later (test/retest method). The correlations between answers at the first and second administration of the questionnaire were evaluated using the Kappa statistic and Spearman's coefficient.
RESULTS:
After verifying the feasibility of the questionnaire, we conducted a reliability analysis on 132 completed questionnaires. The percentage of agreement between the first and the second responses given was over 70%, all K values being greater than 0.6. The analysis of calories and macronutrients also showed good agreement.
CONCLUSIONS:
The questionnaire drawn up for the study proved to be sufficiently reliable for gathering information about the factors of interest in our study of the relationship between air pollution and early biological effects in children