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Title: Quantum nuclear pasta and nuclear symmetry energy

Authors:
; ;
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1356732
Grant/Contract Number:
FG02-87ER40365; NA0002574
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Physical Review C
Additional Journal Information:
Journal Volume: 95; Journal Issue: 5; Related Information: CHORUS Timestamp: 2017-05-11 22:09:08; Journal ID: ISSN 2469-9985
Publisher:
American Physical Society
Country of Publication:
United States
Language:
English

Citation Formats

Fattoyev, F. J., Horowitz, C. J., and Schuetrumpf, B.. Quantum nuclear pasta and nuclear symmetry energy. United States: N. p., 2017. Web. doi:10.1103/PhysRevC.95.055804.
Fattoyev, F. J., Horowitz, C. J., & Schuetrumpf, B.. Quantum nuclear pasta and nuclear symmetry energy. United States. doi:10.1103/PhysRevC.95.055804.
Fattoyev, F. J., Horowitz, C. J., and Schuetrumpf, B.. 2017. "Quantum nuclear pasta and nuclear symmetry energy". United States. doi:10.1103/PhysRevC.95.055804.
@article{osti_1356732,
title = {Quantum nuclear pasta and nuclear symmetry energy},
author = {Fattoyev, F. J. and Horowitz, C. J. and Schuetrumpf, B.},
abstractNote = {},
doi = {10.1103/PhysRevC.95.055804},
journal = {Physical Review C},
number = 5,
volume = 95,
place = {United States},
year = 2017,
month = 5
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on May 11, 2018
Publisher's Accepted Manuscript

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  • X-ray observations of the neutron star (NS) in the Cas A supernova remnant over the past decade suggest the star is undergoing a rapid drop in surface temperature of ≈2%-5.5%. One explanation suggests the rapid cooling is triggered by the onset of neutron superfluidity in the core of the star, causing enhanced neutrino emission from neutron Cooper pair breaking and formation (PBF). Using consistent NS crust and core equations of state (EOSs) and compositions, we explore the sensitivity of this interpretation to the density dependence of the symmetry energy L of the EOS used, and to the presence of enhanced neutrinomore » cooling in the bubble phases of crustal ''nuclear pasta''. Modeling cooling over a conservative range of NS masses and envelope compositions, we find L ≲ 70 MeV, competitive with terrestrial experimental constraints and other astrophysical observations. For masses near the most likely mass of M ≳ 1.65 M {sub ☉}, the constraint becomes more restrictive 35 ≲ L ≲ 55 MeV. The inclusion of the bubble cooling processes decreases the cooling rate of the star during the PBF phase, matching the observed rate only when L ≲ 45 MeV, taking all masses into consideration, corresponding to NS radii ≲ 11 km.« less
  • The first results of a new three-dimensional, finite temperature Skyrme-Hartree-Fock+BCS study of the properties of inhomogeneous nuclear matter at densities and temperatures leading to the transition to uniform nuclear matter are presented. Calculations are carried out in a cubic box representing a unit cell of the locally periodic structure of the matter. A constraint is placed on the two independent components of the quadrupole moment of the neutron density to investigate the dependence of the total energy density of matter on the geometry of the nuclear structure in the unit cell. This approach allows self-consistent modeling of effects such asmore » (i) neutron drip, resulting in a neutron gas external to the nuclear structure; (ii) shell effects of bound and unbound nucleons; (iii) the variety of exotic nuclear shapes that emerge, collectively termed nuclear pasta; and (iv) the dissolution of these structures into uniform nuclear matter as density and/or temperature increase. In Part I of this work the calculation of the properties of inhomogeneous nuclear matter in the core collapse of massive stars is reported. Emphasis is on exploring the effects of the numerical method on the results obtained; notably, the influence of the finite cell size on the nuclear shapes and energy-density obtained. Results for nuclear matter in {beta} equilibrium in cold neutrons stars are the subject of Part II. The calculation of the band structure of unbound neutrons in neutron star matter, yielding thermal conductivity, specific heat, and entrainment parameters, is outlined in Part III. Calculations are performed at baryon number densities of n{sub b}=0.04-0.12 fm{sup -3}, a proton fraction of y{sub p}=0.3 and temperatures in the range 0-7.5 MeV. A wide variety of nuclear shapes are shown to emerge. It is suggested that thermodynamical properties change smoothly in the pasta regime up to the transition to uniform matter; at that transition, thermodynamic properties of the matter vary discontinuously, indicating a phase transition of first or second order. The calculations are carried out using the SkM* Skyrme parametrization; a comparison with calculations using Sly4 at n{sub b}=0.08 fm{sup -3}, T=0 MeV is made.« less
  • The first results of a new three-dimensional, finite temperature Skyrme-Hartree-Fock+BCS study of the properties of inhomogeneous nuclear matter at densities and temperatures leading to the transition to uniform nuclear matter are presented. A constraint is placed on the two independent components of the quadrupole moment in order to self-consistently explore the shape phase space of nuclear configurations. The scheme employed naturally allows effects such as (i) neutron drip, which results in an external neutron gas, (ii) the variety of exotic nuclear shapes expected for extremely neutron heavy nuclei, and (iii) the subsequent dissolution of these nuclei into nuclear matter. Inmore » this way, the equation of state can be calculated across phase transitions from lower densities (where one dimensional Hartree-Fock suffices) through to uniform nuclear matter without recourse to interpolation techniques between density regimes described by different physical models.« less