Nuclear Theory·nucl-th

Wednesday·July 22, 2015

7 papers—3 primary·4 cross-listed

01
Bose-Einstein condensates in neutron stars
C.J. Pethick🇩🇰 · Thomas Schaefer🇺🇸 · A. Schwenk🇩🇪
In the two decades since the appearance of the book "Bose-Einstein Condensation" in 1995, there have been a number of developments in our understanding of dense matter. After a brief overview of neutron star structure and the Bose-Einstein condensed phases that have been proposed, we describe selected topics, including neutron and proton pairing gaps, the physics of the inner crust of neutron stars, where a neutron fluid penetrates a lattice of nuclei, meson condensates, and pairing in dense quark matter. Especial emphasis is placed on basic physical effects and on connections to the physics of cold atomic gases.
nucl-thastro-ph.HEcond-mat.quant-gashep-ph23 citations
02
Correlations between bulk parameters in relativistic and nonrelativistic hadronic mean-field models
B. M. Santos🇧🇷 · M. Dutra🇧🇷 · O. Lourenço🇧🇷 · A. Delfino🇧🇷
In this work, we study the arising of correlations among some isoscalar ( $K_{o}$ , $Q_{o}$ , and $I_{o}$ ) and isovector ( $J$ , $L_{o}$ , $K_{sy m}^{o}$ , $Q_{sy m}^{o}$ , and $I_{sy m}^{o}$ ) bulk parameters in nonrelativistic and relativistic hadronic mean-field models. For the former, we investigate correlations in Skyrme and Gogny parametrizations, as well as in the nonrelativistic (NR) limit of relativistic point-coupling models. We provide analytical correlations among bulk parameters for the NR limit, discussing the conditions in which they are linear ones. Based on a recent study [B. M. Santos et al., Phys. Rev. C 90, 035203 (2014)], we also show that some correlations presented in the NR limit are reproduced for relativistic models presenting cubic and quartic self-interactions in the scalar field $σ$ , mostly studied in this work in the context of the relativistic framework. We also discuss how the crossing points, observed in the density dependence of some bulk parameters, can be seen as a signature of linear correlations between the specific bulk quantity presenting the crossing, and its immediately next order parameter.
nucl-thastro-ph.SRPRC(2015)·16 citations
03
A simple formula for local burnup based on constant relative reaction rate per nuclei
Cenxi Yuan · Xuming Wang · Shengli Chen
A simple and analytical formula is suggested to solve the problems of the local burnup and the isotope distributions. The present method considers two extreme conditions of neutrons penetrating the fuel rod. Based on these considerations, the formula is obtained to calculate the reaction rates of $^{235}$ U, $^{238}$ U, and $^{239}$ Pu and straightforward the local burnup and the isotope distributions. Starting from an initial burnup level, the parameters of the formula are fitted to the reaction rates given by a Monte Carlo (MC) calculation. Then the present formula independently gives very similar results as the MC calculation from the starting to high burnup level, but takes just a few minutes. The relative reaction rates are found to be almost independent on the radius (except $(n, γ)$ of $^{238}$ U) and the burnup, providing a solid background for the present formula. A more realistic examination is also performed when the fuel rods locate in an assembly. A combination of the present formula and the MC calculation is expected to have a nice balance on the accuracy and the cost on time.
nucl-thphysics.ins-detScience and Technology of Nuclear Install…·1 citation

Affiliations

first authorsco-authorsvia INSPIRE

Bose-Einstein condensates in neutron stars

Correlations between bulk parameters in relativistic and nonrelativistic hadronic mean-field models

A simple formula for local burnup based on constant relative reaction rate per nuclei

Affiliations