Abstract
Detailed knowledge of neutrino transport properties in matter is crucial for an understanding of the evolution of supernovae and of neutron star cooling. We investigate screening of neutrino scattering from a dense degenerate gas of electrons, protons and neutrons. We take into account correlations induced by the Coulomb interactions of the electrons of the electrons and protons, and the strong interactions of the protons and neutrons. Nuclear matter is described by the σω model of quantum hadrodynamics. Results are presented for typical astrophysical scenarios. The differential cross section is strongly reduced at large energy transfer, where electrons dominate, and slightly reduced for small energy transfer, where nucleons dominate. At large densities, the nucleon effective mass is considerably lower than the free mass, and the region dominated by nucleons extends to larger energy transfer than for free nucleons.
| Original language | English |
|---|---|
| Pages (from-to) | 665-684 |
| Number of pages | 20 |
| Journal | Nuclear Physics A |
| Volume | 531 |
| Issue number | 3-4 |
| DOIs | |
| State | Published - Sep 1991 |
| Externally published | Yes |
Bibliographical note
Funding Information:We have investigated neutrino neutral current interactions in a degenerate gas of electrons, protons and neutrons. The ground state is described by a highly relativistic Fermi gas of electrons, and its hadronic component by the O'W model of quantum hadrodynamics. The differen-tial cross section for scattering from protons and neutrons is, at fixed three-momentum transfer, shifted to larger values of the energy transfer due to the smaller effective mass of nucleons in the medium. This shift is large in the late stage of neutron star cooling where densities are high. Correlations are included in RPA. The electromagnetic correlations strongly reduce the cross section at large energy transfer where electrons dominate. At high densities (neutron star cooling) the correlations induced by the a and w mesons reduce the cross section at small energy transfer by typically 209/6 . At low densities (early stage of a supernova), we find a strong enhancement at small energy transfer and a small reduction at intermediate energy transfer. This screening ofthe vector neutral current interactions is important only for v,, or F,,, . An assessment of the effects of the screened neutrino cross sections reported here on the evolution of stellar collapse requires detailed supernova simulations. The extension of this relativistic many-body calculation to finite temperature is under way, using a real-time formalism 13). This work is supported by US Department ofEnergy under contract DE-FG2- 87ER40365 and by the Deutsche Forschungsgemeinschaft .
Funding
We have investigated neutrino neutral current interactions in a degenerate gas of electrons, protons and neutrons. The ground state is described by a highly relativistic Fermi gas of electrons, and its hadronic component by the O'W model of quantum hadrodynamics. The differen-tial cross section for scattering from protons and neutrons is, at fixed three-momentum transfer, shifted to larger values of the energy transfer due to the smaller effective mass of nucleons in the medium. This shift is large in the late stage of neutron star cooling where densities are high. Correlations are included in RPA. The electromagnetic correlations strongly reduce the cross section at large energy transfer where electrons dominate. At high densities (neutron star cooling) the correlations induced by the a and w mesons reduce the cross section at small energy transfer by typically 209/6 . At low densities (early stage of a supernova), we find a strong enhancement at small energy transfer and a small reduction at intermediate energy transfer. This screening ofthe vector neutral current interactions is important only for v,, or F,,, . An assessment of the effects of the screened neutrino cross sections reported here on the evolution of stellar collapse requires detailed supernova simulations. The extension of this relativistic many-body calculation to finite temperature is under way, using a real-time formalism 13). This work is supported by US Department ofEnergy under contract DE-FG2- 87ER40365 and by the Deutsche Forschungsgemeinschaft .
| Funders | Funder number |
|---|---|
| US Department ofEnergy | DE-FG2- 87ER40365 |
| Deutsche Forschungsgemeinschaft |