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arXiv · 0808.0330

Unified approach to structure factors and neutrino processes in nucleon matter

G. I. Lykasov·C. J. Pethick·A. Schwenk
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Abstract

We present a unified approach to neutrino processes in nucleon matter based on Landau's theory of Fermi liquids that includes one- and two-quasiparticle-quasihole pair states as well as mean-field effects. We show how rates of neutrino processes involving two nucleons may be calculated in terms of the collision integral in the Landau transport equation for quasiparticles. Using a relaxation time approximation, we solve the transport equation for density and spin-density fluctuations and derive a general form for the response functions. We apply our approach to neutral-current processes in neutron matter, where the spin response function is crucial for calculations of neutrino elastic and inelastic scattering, neutrino-pair bremsstrahlung and absorption from strongly-interacting nucleons. We calculate the relaxation rates using modern nuclear interactions and including many-body contributions, and find that rates of neutrino processes are reduced compared with estimates based on the one-pion exchange interaction, which is used in current simulations of core-collapse supernovae.

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G. I. Lykasov, C. J. Pethick, A. Schwenk. 2008-10-22. Unified approach to structure factors and neutrino processes in nucleon matter. https://doi.org/10.1103/physrevc.78.045803

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