Role of nonGaussian quantum fluctuations in neutrino entanglement
Abstract
The flavor evolution of neutrinos in environments with large neutrino number densities is an open problem at the nexus of astrophysics and neutrino flavor physics. Among the many unanswered questions pertaining to this problem, it remains to be determined whether neutrinoneutrino coherent scattering can give rise to nontrivial quantum entanglement among neutrinos, and whether this can affect the flavor evolution in a meaningful way. To gain further insight into this question, here we study a simple system of two interacting neutrino beams and obtain the exact phase space explored by this system using the Husimi quasiprobability distribution. We observe that the entanglement induced by the coupling leads to strong delocalization in phasespace with largely nonGaussian quantum fluctuations. The link between the neutrino entanglement and quantum fluctuations is illustrated using the one and twoneutrino entropy. In addition, we propose an approximate phasespace method to describe the interacting neutrinos problem, where the exact evolution is replaced by a set of independent meanfield evolutions with a statistical sampling of the initial conditions. The phasespace approach provides a simple and accurate method to describe the gross features of the neutrino entanglement problem. Applications are shown using timeindependent and timedependent Hamiltonians in the nonadiabatic regime.
 Publication:

Physical Review D
 Pub Date:
 December 2022
 DOI:
 10.1103/PhysRevD.106.123006
 arXiv:
 arXiv:2205.09384
 Bibcode:
 2022PhRvD.106l3006L
 Keywords:

 Nuclear Theory;
 High Energy Physics  Phenomenology;
 Quantum Physics
 EPrint:
 doi:10.1103/PhysRevD.106.123006