Related papers: Nucleon Spin Fluctuations and Neutrino-Nucleon Ene…
Extrapolation of perturbative nucleon spin fluctuation rates seems to suggest a strong suppression of weak interactions in supernova cores. We derive a new sum rule for the dynamical spin-density structure function which relates the spin…
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.…
In the hot and dense medium of a supernova (SN) core, the nucleon spins fluctuate so fast that the axial-vector neutrino opacity and the axion emissivity are expected to be significantly modified. Axions with $m_a\alt10^{-2}\,{\rm eV}$ are…
We calculate the differential scattering rate for thermal neutrinos in a hot and dilute gas of interacting neutrons using linear response theory. The dynamical structure factors for density and spin fluctuations of the strongly interacting…
Nucleon spin fluctuations in a dense medium reduce the ``naive'' values of weak interaction rates (neutrino opacities, neutrino emissivities). We extend previous studies of this effect to the degenerate case which is appropriate for neutron…
We develop a simple model for the evolution of a nucleon spin in a hot and dense nuclear medium. A given nucleon is limited to one-dimensional motion in a distribution of external, spin-dependent scattering potentials. We calculate the…
We studied possible modifications of the neutrino - nucleon scattering rate due to the nucleon - nucleon collisions in the hot dense matter which we find in the supernova core. We show that the finite width of the nucleon spectral function…
Elastic scattering on nucleons, \nu N -> N \nu, is the dominant supernova (SN) opacity source for \mu and \tau neutrinos. The dominant energy- and number-changing processes were thought to be \nu e^- -> e^- \nu and \nu\bar \nu <-> e^+ e^-…
Neutrinos produced during the collapse of a massive star are trapped in a nuclear medium (the proto-neutron star). Typically, neutrino energies (10-100 MeV) are of the order of nuclear giant resonances energies. Hence, neutrino propagation…
Neutrinos are known to play important roles in many astrophysical scenarios from the early period of the big bang to current stellar evolution being a unique messenger of the fusion reactions occurring in the center of our sun. In…
In a supernova (SN) core during infall and after collapse, neutrinos are trapped by their interactions with nucleons. For the axial-vector current interactions it is not enough to include static particle-particle correlations. Even the…
Neutrinos emitted during the collapse, bounce and subsequent explosion provide information about supernova dynamics. The neutrino spectra are determined by weak interactions with nuclei and nucleons in the inner regions of the star, and…
{We calculate the neutrino emissivity of superfluid neutron matter in the inner crust of neutron stars. We find that neutrino emission due to fluctuations resulting from the formation of Cooper pairs at finite temperature is highly…
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…
Neutrino flow is the dominant mechanism of energy transfer in the latest stages of supernovae explosions and in compact stars. The Standard Model of particle physics and accelerator data, provide a satisfactory description of neutrino…
Axial-vector interactions of neutrinos and axions with a medium are based on structure functions which cannot be calculated in simple perturbative terms for nuclear densities. We use the SN~1987A neutrino signal duration to estimate the…
Including nucleon-nucleon correlations due to both Fermi statistics and nuclear forces, we have developed a general formalism for calculating the neutral-current neutrino-nucleon opacities in nuclear matter. We derive corrections to the…
The neutrino flux and spectra formation in a supernova core is studied by using a Monte Carlo code. The dominant opacity contribution for nu_mu and nu_tau is elastic scattering on nucleons. In addition we switch on or off a variety of…
The mu- and tau-neutrinos emitted from a proto-neutron star are produced by nucleonic bremsstrahlung N + N -> N + N + nu + nu-bar and pair annihilation e^+ + e^- -> nu + nu-bar, reactions which freeze out at the "energy sphere." Before…
One- and two-dimensional hydrodynamical simulations of neutrino-driven supernova explosions are discussed. The simulations cover the phase between the stagnation of the prompt shock and about one second after core bounce. Systematic…