A Relativistic quantum approach to neutrino and antineutrino emission via the direct Urca process in strongly magnetized neutron-star matter

強磁性の中性子星における直接ウルカ過程によるニュートリノと反ニュートリノ放出への相対論的量子論アプローチ

丸山 智幸*; Baha Balantekin, A.*; Cheoun, M.-K.*; 梶野 敏貴*; 日下部 元彦*; Mathews, G. J.*

Maruyama, Tomoyuki*; Baha Balantekin, A.*; Cheoun, M.-K.*; Kajino, Toshitaka*; Kusakabe, Motohiko*; Mathews, G. J.*

We study neutrino and antineutrino emission from the direct Urca process in neutron-star matter in the presence of strong magnetic fields. We calculate the neutrino emissivity of the direct Urca process, whereby a neutron converts to a proton, an electron and an antineutrino, or a proton-electron pair converts to a neutron-neutrino pair. We solve exact wave functions for protons and electrons in the states described with Landau levels. We find that the direct Urca process can satisfy the kinematic constraints even in density regions where this process could not normally occur in the absence of a magnetic field.