skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Neutrino scattering in heterogeneous supernova plasmas

Abstract

Neutrinos in core-collapse supernovae are likely trapped by neutrino-nucleus elastic scattering. Using molecular dynamics simulations, we calculate neutrino mean free paths and ion-ion correlation functions for heterogeneous plasmas. Mean free paths are systematically shorter in plasmas containing a mixture of ions compared to a plasma composed of a single ion species. This is because neutrinos can scatter from concentration fluctuations. The dynamical response function of a heterogeneous plasma is found to have an extra peak at low energies describing the diffusion of concentration fluctuations. Our exact molecular dynamics results for the static structure factor reduce to the Debye-Hueckel approximation, but only in the limit of very low momentum transfers.

Authors:
; ;  [1];  [2]
  1. Department of Physics and Nuclear Theory Center, Indiana University, Bloomington, Indiana 47405 (United States)
  2. (United States)
Publication Date:
OSTI Identifier:
20864243
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. C, Nuclear Physics; Journal Volume: 74; Journal Issue: 6; Other Information: DOI: 10.1103/PhysRevC.74.065801; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; APPROXIMATIONS; COMPUTERIZED SIMULATION; CORRELATION FUNCTIONS; DIFFUSION; ELASTIC SCATTERING; FLUCTUATIONS; IONS; MEAN FREE PATH; MIXTURES; MOLECULAR DYNAMICS METHOD; MOMENTUM TRANSFER; NEUTRINOS; NUCLEI; PLASMA; RESPONSE FUNCTIONS; STRUCTURE FACTORS; SUPERNOVAE; TRAPPING

Citation Formats

Caballero, O. L., Horowitz, C. J., Berry, D. K., and University Information Technology Services, Indiana University, Bloomington, Indiana 47408. Neutrino scattering in heterogeneous supernova plasmas. United States: N. p., 2006. Web. doi:10.1103/PHYSREVC.74.065801.
Caballero, O. L., Horowitz, C. J., Berry, D. K., & University Information Technology Services, Indiana University, Bloomington, Indiana 47408. Neutrino scattering in heterogeneous supernova plasmas. United States. doi:10.1103/PHYSREVC.74.065801.
Caballero, O. L., Horowitz, C. J., Berry, D. K., and University Information Technology Services, Indiana University, Bloomington, Indiana 47408. Fri . "Neutrino scattering in heterogeneous supernova plasmas". United States. doi:10.1103/PHYSREVC.74.065801.
@article{osti_20864243,
title = {Neutrino scattering in heterogeneous supernova plasmas},
author = {Caballero, O. L. and Horowitz, C. J. and Berry, D. K. and University Information Technology Services, Indiana University, Bloomington, Indiana 47408},
abstractNote = {Neutrinos in core-collapse supernovae are likely trapped by neutrino-nucleus elastic scattering. Using molecular dynamics simulations, we calculate neutrino mean free paths and ion-ion correlation functions for heterogeneous plasmas. Mean free paths are systematically shorter in plasmas containing a mixture of ions compared to a plasma composed of a single ion species. This is because neutrinos can scatter from concentration fluctuations. The dynamical response function of a heterogeneous plasma is found to have an extra peak at low energies describing the diffusion of concentration fluctuations. Our exact molecular dynamics results for the static structure factor reduce to the Debye-Hueckel approximation, but only in the limit of very low momentum transfers.},
doi = {10.1103/PHYSREVC.74.065801},
journal = {Physical Review. C, Nuclear Physics},
number = 6,
volume = 74,
place = {United States},
year = {Fri Dec 15 00:00:00 EST 2006},
month = {Fri Dec 15 00:00:00 EST 2006}
}
  • Based on the shell model for Gamow-Teller and the random phase approximation for forbidden transitions, we calculate cross sections for inelastic neutrino-nucleus scattering (INNS) under supernova (SN) conditions, assuming a matter composition given by nuclear statistical equilibrium. The cross sections are incorporated into state-of-the-art stellar core-collapse simulations with detailed energy-dependent neutrino transport. While no significant effect on the SN dynamics is observed, INNS increases the neutrino opacities noticeably and strongly reduces the high-energy tail of the neutrino spectrum emitted in the neutrino burst at shock breakout. Relatedly the expected event rates for the observation of such neutrinos by earthbound detectorsmore » are reduced by up to about 60%.« less
  • Bounding values of the influence the hypothetical neutrino magneticmoment has on the dynamics of neutrino emission by supernovae have beendetermined from the detection of SN1987A neutrinos. The purpose of thiscomment is to note that the dynamics of resonance transition of right/minus/handed neutrinos to left/minus/handed neutrinos in the strong magnetic fieldof the supernova interior can be altered radically if ..nu../sub e//nue/scattering is taken account. (AIP)
  • In a nuclear medium, spin-dependent forces cause the nucleon spins to fluctuate with a rate {Gamma}{sub {sigma}}. We have previously shown that as a consequence the effective axial-vector current neutrino-nucleon scattering cross section is reduced. Here, we calculate this reduction explicitly in the perturbative limit {Gamma}{sub {sigma}}{lt}{ital T}. By virtue of an exact sum rule of the spin-density structure function, we express the modified cross section in terms of the matrix element for neutrino-nucleon scattering in the presence of a spin-dependent nuclear potential. This representation allows for a direct comparison with, and confirmation of, Sawyer{close_quote}s related perturbative result. In amore » supernova core with a typical temperature {ital T}=10MeV, the perturbative limit is relevant for densities {rho}{approx_lt}10{sup 13} g cm{sup {minus}3} and thus applies around the neutrino sphere. There, the cross-section reduction is of order a few percent and thus not large; however, a new mode of energy transfer between neutrinos and nucleons is enabled which may be important for neutrino spectra formation. We derive an analytic perturbative expression for the rate of energy transfer. {copyright} {ital 1996 The American Physical Society.}« less
  • In a nuclear medium, spin-dependent forces cause the nucleon spins to fluctuate with a rate \Gamma_\sigma. We have previously shown that as a consequence the effective axial-current neutrino-nucleon scattering cross section is reduced. Here, we calculate this reduction explicitly in the perturbative limit \Gamma_\sigma\ll T. By virtue of an exact sum rule of the spin-density structure function, we express the modified cross section in terms of the matrix element for neutrino-nucleon scattering in the presence of a spin-dependent nuclear potential. This representation allows for a direct comparison with and confirmation of Sawyer's related perturbative result. In a supernova core withmore » a typical temperature T=10\,\rm MeV, the perturbative limit is relevant for densities \rho\alt10^{13}\,\rm g\,cm^{-3} and thus applies around the neutrino sphere. There, the cross-section reduction is of order a few percent and thus not large; however, a new mode of energy transfer between neutrinos and nucleons is enabled which may be important for neutrino spectra formation. We derive an analytic perturbative expression for the rate of energy transfer.« less