Rapid cooling of magnetized neutron stars
  The neutrino emissivities resulting from direct URCA processes in neutron stars are calculated in a relativistic Dirac-Hartree approach in presence of a magnetic field. In a quark or a hyperon matter environment, the emissivity due to nucleon direct URCA processes is suppressed relative to that from pure nuclear matter. In all the cases studied, the magnetic field enhances emissivity compared to the field-free cases. 
Debades Bandyopadhyay, Somenath Chakrabarty, Prantick Dey, and Subrata   Pal