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On some singularities of the correlation functions that determine neutrino opacities

R. F. Sawyer
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Abstract

Certain perturbation graphs in the calculation of the effects of the medium on neutrino scattering in supernova matter have a nonintegrable singularity in a physical region. A number of papers have addressed the apparent pathology through an ansatz that invokes higher order (rescattering) effects. Taking the Gamow-Teller terms as an example, we display an expression for the spin-spin correlation function that determines the cross-sections. It is clear from the form that there are no pathologies in the order by order perturbation expansion. Explicit formulae are given for a simple case, leading to an answer that is very different from one given by other authors.

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R. F. Sawyer. 1998-12-18. On some singularities of the correlation functions that determine neutrino opacities. https://doi.org/10.1103/physrevd.60.023002

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