[Submitted on 30 Nov 2016] (cross-list from hep-ph)
Energy Conservation and the Chiral Magnetic Effect
David B. Kaplan🇺🇸 · Sanjay Reddy🇺🇸 · Srimoyee Sen🇺🇸
We analyze the chiral magnetic effect in a homogeneous neutral plasma from the point of view of energy conservation, and construct an effective potential for the growth of maximally helical perturbations of the electromagnetic field. We show that a negative curvature at the origin of the potential, indicating instability of the plasma, is induced by a chiral asymmetry in electron Fermi energy, as opposed to number density, while the potential grows at large field value. It follows that the ground state for a plasma has zero magnetic helicity; a nonzero electron mass will allow an excited state of a plasma with nonzero helicity to relax to that ground state quickly. We conclude that a chiral plasma instability triggered by weak interactions is not a viable mechanism for explaining magnetic fields in stars except possibly when dynamics drives the system far from equilibrium.
- Comments:
- We have corrected a sign error. But the main conclusions of the paper remain unchanged
- Subjects:
- High Energy Physics — Phenomenology (hep-ph); High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
- arXiv:
- 1612.00032 [pdf]