251. Flavour mixing of neutrinos and baryon asymmetry of the universe
- Author
-
Takehiko Asaka and Hiroyuki Ishida
- Subjects
Physics ,Nuclear and High Energy Physics ,Particle physics ,Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,media_common.quotation_subject ,High Energy Physics::Phenomenology ,FOS: Physical sciences ,General Relativity and Quantum Cosmology (gr-qc) ,Asymmetry ,General Relativity and Quantum Cosmology ,Baryogenesis ,Massless particle ,Baryon ,High Energy Physics - Phenomenology ,High Energy Physics - Phenomenology (hep-ph) ,Baryon asymmetry ,Grand Unified Theory ,CP violation ,High Energy Physics::Experiment ,Neutrino ,Astrophysics - Cosmology and Nongalactic Astrophysics ,media_common - Abstract
We investigate baryogenesis in the $\nu$MSM, which is the Minimal Standard Model (MSM) extended by three right-handed neutrinos with Majorana masses smaller than the weak scale. In this model the baryon asymmetry of the universe (BAU) is generated via flavour oscillation between right-handed neutrinos. We consider the case when BAU is solely originated from the CP violation in the mixing matrix of active neutrinos. We perform analytical and numerical estimations of the yield of BAU, and show how BAU depends on mixing angles and CP violating phases. It is found that the asymmetry in the inverted hierarchy for neutrino masses receives a suppression factor of about 4% comparing with the normal hierarchy case. It is, however, pointed out that, when $\theta_{13}=0$ and $\theta_{23} = \pi/4$, baryogenesis in the normal hierarchy becomes ineffective, and hence the inverted hierarchy case becomes significant to account for the present BAU., Comment: 15 pages, 7 figures
- Published
- 2010