Pulsar Acceleration by Asymmetric Emission of Sterile Neutrinos

A convincing explanation for the observed pulsar large peculiar velocities isstill missing. We argue that any viable particle physics solution would mostlikely involve the resonant production of a non-interacting neutrino $\nu_s$ ofmass $m_{\nu_s}\sim 20$--50 keV. We propose a model where anisotropic magneticfield configurations strongly bias the resonant spin flavour precession of tauantineutrinos into $\nu_s$. For internal magnetic fields $B_{int} \gsim10^{15}$ G a $\bar\nu_\tau$-$\nu_s$ transition magnetic moment of the order of$10^{-12}$ Bohr magnetons is required. The asymmetric emission of $\nu_s$ fromthe core can produce sizeable natal kicks and account for recoil velocities ofseveral hundred kilometers per second.Comment: 14 pages, AASTEX, 2 figures (uses epsfig). Minor typos corrected. Added acknowledgments to the funding institutes BID and Colciencia