Production of a sterile species: quantum kinetics
| dc.creator | Boyanovsky, D. | |
| dc.creator | Ho, C. M. | |
| dc.date | 2007-05-04 | |
| dc.date | 2007-10-05 | |
| dc.date.accessioned | 2026-07-07T10:59:57Z | |
| dc.date.available | 2026-07-07T10:59:57Z | |
| dc.description | Production of a sterile species is studied within an effective model of active-sterile neutrino mixing in a medium in thermal equilibrium. The quantum kinetic equations for the distribution functions and coherences are obtained from two independent methods: the effective action and the quantum master equation. The decoherence time scale for active-sterile oscillations is $τ_{dec} = 2/Γ_{aa}$, but the evolution of the distribution functions is determined by the two different time scales associated with the damping rates of the quasiparticle modes in the medium: $Γ_1=Γ_{aa}\cos^2\tm ; Γ_2=Γ_{aa}\sin^2\tm$ where $Γ_{aa}$ is the interaction rate of the active species in absence of mixing and $\tm$ the mixing angle in the medium. These two time scales are widely different away from MSW resonances and preclude the kinetic description of active-sterile production in terms of a simple rate equation. We give the complete set of quantum kinetic equations for the active and sterile populations and coherences and discuss in detail the various approximations. A generalization of the active-sterile transition probability \emph{in a medium} is provided via the quantum master equation. We derive explicitly the usual quantum kinetic equations in terms of the ``polarization vector'' and show their equivalence to those obtained from the quantum master equation and effective action. | |
| dc.description | To appear in Phys. Rev. D | |
| dc.identifier | https://arxiv.org/abs/0705.0703 | |
| dc.identifier | http://arxiv.org/abs/0705.0703 | |
| dc.identifier | Phys.Rev.D76:085011,2007 | |
| dc.identifier | doi:10.1103/PhysRevD.76.085011 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/187584 | |
| dc.subject | High Energy Physics - Phenomenology | |
| dc.title | Production of a sterile species: quantum kinetics | |
| dc.type | text |