Thermalisation of light sterile neutrinos

18th International Symposium on Particles Strings and Cosmology

Tram, Thomas^1

Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark^1

关键词: Early universe;    Ground based;    Mass difference;    Momentum-dependent;    Neutrino experiments;    Quantum kinetic equations;    Sterile neutrinos;    Thermalisation;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/485/1/012016/pdf
DOI  :  10.1088/1742-6596/485/1/012016

来源: IOP

【 摘 要 】

We calculate the thermalisation process of light, sterile neutrinos in the early Universe for a range of mixing angles and mass-differences. We show that adding a large initial lepton asymmetry suppress thermalisation significantly. In particular, a sterile neutrino that explains the anomalies seen in ground based neutrino experiments can be made compatible with cosmology. We compute the degree of thermalisation in the (1 active + 1 sterile) scenario and give the effective number of thermalised species just before BBN begins. Resonances are taken properly taken into account, since we solve the full, momentum dependent equations, knowns as the Quantum Kinetic Equations. These proceedings are partly based on the paper [1].