The ground state of chargeless fermions with finite magnetic moment

TitleThe ground state of chargeless fermions with finite magnetic moment
Publication TypeJournal Article
Year of Publication2006
AuthorsMahanti, SD, Jha, SS
JournalJournal of Physics A: Mathematical and General
Volume39
Issue6
Pagination1239–1249
Date Published02/2006
Abstract

We consider the ground state of a system of chargeless fermions, such as neutrinos, of mass m and magnetic moment m interacting through long-range magnetic dipole interaction, within the framework of a {Hartree-Fock} variational approach. At high densities the uniform paramagnetic state becomes unstable towards a ferromagnetic state with quadrupolar deformation of the Fermi surface. The exchange energy which is attractive dominates the repulsive kinetic energy. If we let the density be a variable, then above a certain density the system will collapse to an infinite density state unless another short-range interaction stops the collapse. In the case of large deformations, the possibility of a purely dipolar deformation exists.