Background: The response of neutron star matter to weak probes determines the neutrino mean free path, the knowledge of which is required for the description of neutron star cooling.

Purpose: We compute the response of cold neutron matter to neutral-current interactions, to determine the mean free path of low-energy neutrinos.

Methods: Our calculations have been carried out using an effective interaction and effective operators consistently derived within the formalism of correlated basis functions. To check the accuracy of the calculation, we have also employed the Landau theory of normal Fermi liquids and the auxiliary field diffusion Monte Carlo approach.

Results: The neutrino mean free path obtained from the calculated responses turns out to be strongly affected by both short- and long-range correlations, leading to a sizable increase with respect to the prediction of the Fermi gas model.

Conclusions: Our results show that for a realistic description of the neutron matter response and of the neutrino mean free path both long- and short-range correlations need to be taken into account.

• Received 1 October 2013

DOI:https://doi.org/10.1103/PhysRevC.89.025804