Title: Nuclear pasta in hot dense matter and its implications for neutrino scattering

Abstract

The abundance of large clusters of nucleons in neutron-rich matter at subnuclear density is found to be greatly reduced by finite-temperature effects when matter is close to β equilibrium, compared to the case where the electron fraction is fixed at Y_e > 0.1 , as often considered in the literature. Large nuclei and exotic nonspherical nuclear configurations called pasta, favored in the vicinity of the transition to uniform matter at T = 0 , dissolve at a relatively low temperature T_u as protons leak out of nuclei and pasta. For matter at β-equilibrium with a negligible neutrino chemical potential we find that T$$β\atop{u}$$ ≃ 4 ± 1 MeV for realistic equations of state. This is lower than the maximum temperature T$$β\atop{max}$$ ≃ 9 ± 1 MeV at which nuclei can coexist with a gas of nucleons and can be explained by a change in the nature of the transition to uniform matter called retrograde condensation. An important new finding is that coherent neutrino scattering from nuclei and pasta makes a modest contribution to the opacity under the conditions encountered in supernovas and neutron star mergers. This is because large nuclear clusters dissolve at most relevant temperatures, and at lower temperatures, when clusters are present, Coulomb correlations between them suppress coherent neutrino scattering off individual clusters. Lastly, implications for neutrino signals from galactic supernovas are briefly discussed.

Authors:

Roggero, Alessandro ^[1]; Margueron, Jerome ^[2]; Roberts, Luke F. ^[3]; Reddy, Sanjay ^[4]

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+ Show Author Affiliations

1. Univ. of Washington, Seattle, WA (United States). Inst. for Nuclear Theory; Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2. Univ. of Washington, Seattle, WA (United States). Inst. for Nuclear Theory; Univ. de Lyon, Villeurbanne (France); Univ. Claude Bernard Lyon, Villeurbanne (France). Inst. de Physique Nucleaire de Lyon
3. Michigan State Univ., East Lansing, MI (United States). National Superconducting Lab. and Dept. of Physics and Astronomy
4. Univ. of Washington, Seattle, WA (United States). Inst. for Nuclear Theory

Publication Date:

Mon Apr 16 00:00:00 EDT 2018

Research Org.:

Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

Sponsoring Org.:

USDOE Office of Science (SC). Nuclear Physics (NP) (SC-26); USDOE

OSTI Identifier:

1438361

Alternate Identifier(s):

OSTI ID: 1433276

Report Number(s):

LA-UR-17-29841
Journal ID: ISSN 2469-9985; PRVCAN; TRN: US1900421

Grant/Contract Number:  

AC52-06NA25396; FG02-00ER41132; SC0017955

Resource Type:

Accepted Manuscript

Journal Name:

Physical Review C

Additional Journal Information:

Journal Volume: 97; Journal Issue: 4; Journal ID: ISSN 2469-9985

Publisher:

American Physical Society (APS)

Country of Publication:

United States

Language:

English

Subject:

73 NUCLEAR PHYSICS AND RADIATION PHYSICS; 79 ASTRONOMY AND ASTROPHYSICS; Atomic and Nuclear Physics