Spectral splits of neutrinos as a BCS-BEC crossover type phenomenon

TL;DR

This paper draws an analogy between the spectral split phenomenon in neutrino ensembles from supernovae and the BCS-BEC crossover in cold atomic gases, highlighting similar many-body physics.

Contribution

It introduces a novel analogy linking neutrino spectral splits to BCS-BEC crossover physics, bridging astrophysics and condensed matter.

Findings

Spectral splits resemble BCS-BEC crossover physics.

Neutrino isospin dynamics mirror pair quasispin transformations.

The Hamiltonian evolution is analogous in both systems.

Abstract

We show that the spectral split of a neutrino ensemble which initially consists of electron type neutrinos, is analogous to the BCS-BEC crossover already observed in ultra cold atomic gas experiments. Such a neutrino ensemble mimics the deleptonization burst of a core collapse supernova. Although these two phenomena belong to very different domains of physics, the propagation of neutrinos from highly interacting inner regions of the supernova to the vacuum is reminiscent of the evolution of Cooper pairs between weak and strong interaction regimes during the crossover. The Hamiltonians and the corresponding many-body states undergo very similar transformations if one replaces the pair quasispin of the latter with the neutrino isospin of the former.