Instability of magnetic fields in electroweak plasma driven by neutrino asymmetries

Understand

The magnetohydrodynamics (MHD) is modified to incorporate the parity violation in the Standard Model leading to a new instability of magnetic fields in the electroweak plasma in the presence of nonzero neutrino asymmetries.

• The main ingredient for such a modified MHD is the antisymmetric part of the photon polarization tensor in plasma, where the parity violating neutrino interaction with charged leptons is present.
• We calculate this contribution to the polarization tensor connected with the Chern-Simons term in effective Lagrangian of the electromagnetic field.
• The general expression for such a contribution which depends on the temperature and the chemical potential of plasma as well as on the photon's momentum is derived.