Lepton Asymmetry with Primordial Magnetic Fields

15th Mexican School of Particles and Fields

Cota, Roberto^1 ; Barranco, Juan^1 ; Delepine, David^1 ; Khalil, Shaaban^2,3

Division de Ciencias e Ingenierías, Universidad de Guanajuato, Campus Leon, C.P. 37150, León-Guanajuato, Mexico^1

Centre for Theoretical Physics, Zewail City of Science and Technology, Sheikh Zayed, 12588, Giza, Egypt^2

Department of Mathematics, Faculty of Science, Ain Shams University, Cairo, Egypt^3

关键词: Electroweak phase transition;    Electroweak scale;    Extra-galactic;    Leptogenesis;    Majorana particles;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/468/1/012003/pdf
DOI  :  10.1088/1742-6596/468/1/012003

来源: IOP

【 摘 要 】

If the neutrino are Majorana particles, the neutrino spin flavor precession induced ΔL 2 processes which could be relevant for leptogenesis depending on the strength of neutrino magnetic moments and magnetic fields. Although the extra galactic magnetic fields is extremely weak at present time (about 10-9Gauss), the primordial magnetic field at the electroweak scale could be strong (of order 1017Gauss). Therefore, at this scale, the effects of the spin flavor precession could not be negligible. Using present limit on neutrino magnetic moments, we show that the lepton asymmetry may be reduced by 50% due to the spin flavor precession induced by strong primordial magnetic fields. In addition, the leptogenesis will have different feature from the standard scenario of leptogenesis, where the lepton asymmetry continues to oscillate even after the electroweak phase transition.