1,778 research outputs found
Effective interactions and shell model studies of heavy tin isotopes
We calculate the low-lying spectra of heavy tin isotopes from A=120 to A=130
using the 2s1d0g_{7/2}0h_{11/2} shell to define the model space. An effective
interaction has been derived using 132Sn as closed core employing perturbative
many-body techniques. We start from a nucleon-nucleon potential derived from
modern meson exchange models. This potential is in turn renormalized for the
given medium, 132Sn, yielding the nuclear reaction matrix, which is then used
in perturbation theory to obtain the shell model effective interaction.Comment: 19 pages, Elsevier latex style espart.sty, submitted to Nuclear
Physics
Effective interactions in medium heavy nuclei
We present a brief overview of microscopic nuclear structure approaches to
nuclei with mass number from 100 to 132. The emphasis is on the shell model and
theories for deriving effective interactions starting from the free
interactions between nucleons. New results for (105,106,107)Sb are presented.Comment: Proceedings of RNB5, 3-8 April 2000, Divonne, France. 6 pages,
Elsevier latex style. To appear in Nucl. Phys.
Convergence properties of the effective interaction
The convergence properties of two perturbative schemes to sum the so-called
folded diagrams are critically reviewed, with an emphasis on the intruder state
problem. The methods we study are the approaches of Kuo and co-workers and Lee
and Suzuki. The suitability of the two schemes for shell-model calculations are
discussed.Comment: 10 pages in revtex ver. 3.0. 3 figs can be obtained upon request.
Univerisity of Oslo report UiO/PHYS/93-2
Study of odd-mass N=82 isotones with realistic effective interactions
The microscopic quasiparticle-phonon model, MQPM, is used to study the energy
spectra of the odd , N=82 isotones. The results are compared with
experimental data, with the extreme quasiparticle-phonon limit and with the
results of an unrestricted shell model (SM)
calculation. The interaction used in these calculations is a realistic two-body
G-matrix interaction derived from modern meson-exchange potential models for
the nucleon-nucleon interaction. For the shell model all the two-body matrix
elements are renormalized by the -box method whereas for the MQPM the
effective interaction is defined by the G-matrix.Comment: Elsevier latex style espart, 26 pages, submitted to Nuclear Physics
Social Determinants of Health and the Prevalence of Overweight Status and Mental Health Conditions Among Non-Hispanic Black and Hispanic Children in the United States
Purpose: A growing concern in the United States has been the rise of anxiety and depression and its relation to excessive weight status among non-Hispanic Black and Hispanic children, racial groups with higher-than-average rates of overweight status and obesity. This study explored this prevalence by analyzing individual, interpersonal, and community factors among this population. The study also sought to determine if a correlation exists between elevated weight and mental health issues in the study population.
Methods: Using data from the 2017’s National Survey of Children Health (NSCH), the prevalence of anxiety and depression was investigated among Black and Hispanic children ages 10-17 years old with a BMI greater than the 85th percentile, defined by the CDC as being overweight/obese (N=10,839).
Results: Two-way chi square tests were conducted in SPSS, determining that statistically significant correlates (p \u3c 0.05) existed between the prevalence of overweight/obesity in children and individual, interpersonal, and community factors, with the most significant correlates being individual factors. A significant correlate was found to exist between overweight/obesity and the prevalence of anxiety and depression (p \u3c 0.05, for both); however, when categorized by either race, no significant correlate was observed (p = 0.40, 0.26). Using a simple linear regression model, the most significant variables that correlated with overweight/obese were age, Mental Health Index, Adverse Childhood Experiences (ACE) score, and Family Received Assistance in 31 Last 12 Months. Family Received Assistance in Last 12 Months was indicated as a question on the NCSH.
Conclusion: The results of the study found the most significant correlates to be between individual factors and overweight/obesity in children. The multiple logistic regression model demonstrated that only three variables were significant predictors of overweight/obesity in children after running stepwise selection. Additional studies investigating mental health (MH) and behavioral health factors among children who are overweight or obese (o/o) is recommended
Generalized seniority scheme in light Sn isotopes
The yrast generalized seniority states are compared with the corresponding
shell model states for the case of the Sn isotopes Sn. For most of
the cases the energies agree within 100 keV and the overlaps of the wave
functions are greater than 0.7.Comment: 8 pages, revtex. Submitted to Phys. Rev.
Application of realistic effective interactions to the structure of the Zr isotopes
We calculate the low-lying spectra of the zirconium isotopes Z=40 with
neutron numbers from N=52 to N=60 using the 1p1/20g9/2 proton and
2s1d0g7/20h11/2 neutron sub-shells to define the model space. Effective
proton-proton, neutron--neutron and proton-neutron interactions have been
derived using 88Sr as closed core and employing perturbative many-body
techniques. The starting point is the nucleon-nucleon potential derived from
modern meson exchange models. The comprehensive shell-model calculation
performed in this work provides a qualitative reproduction of essential
properties such as the sub-shell closures in 96Zr and 98Zr.Comment: To appear in Phys Rev C, june 2000, 8 figs, Revtex latex styl
Extended shell-model calculation for even N=82 isotones with realistic effective interactions
The shell model within the shell is applied to
calculate nuclear structure properties of the even Z=52 - 62, N=82 isotones.
The results are compared with experimental data and with the results of a
quasiparticle random-phase approximation (QRPA) calculation. The interaction
used in these calculations is a realistic two-body G-matrix interaction derived
from modern meson-exchange potential models for the nucleon-nucleon
interaction. For the shell model all the two-body matrix elements are
renormalized by the -box method whereas for the QRPA the effective
interaction is defined by the G-matrix.Comment: 25 pages, Elsevier latex style. Submitted to Nuclear Physics
Self-Consistent Nuclear Shell-Model Calculation Starting from a Realistic NN Potential
First self-consistent realistic shell-model calculation for the light p-shell
nuclei is performed, starting from the high-precision nucleon-nucleon (NN)
CD-Bonn potential. This realistic potential is renormalized deriving a
low-momentum NN potential V-low-k that preserves exactly the two-nucleon
low-energy physics. This V-low-k is suitable to derive a self-consistent
Hartree-Fock basis that is employed to derive both effective single-particle
energies and residual two-body matrix elements for the shell-model hamiltonian.
Results obtained show the reliability of such a fundamental microscopic
approach.Comment: 4 pages, 1 figure, 8 tables, to be published on Physics Letters
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