Cosmological family asymmetry and CP violation

Journal Article · Fri Jul 01 04:00:00 EDT 2005 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PhysRevD.72.016006· OSTI ID:20711086

Fujihara, T; Kimura, D; Morozumi, T ^[1]; Kaneko, S ^[2]; Kang, S ^[3]; Tanimoto, M ^[4]

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1. Graduate School of Science, Hiroshima University, Higashi-Hiroshima, 739-8526 (Japan)
2. Department of Physics, Ochanomizu University, Tokyo, 112-8610 (Japan)
3. Seoul National University, Seoul, 151-734 (Korea, Republic of)
4. Department of Physics, Niigata University, Niigata, 950-2181 (Japan)

We discuss how the cosmological baryon asymmetry can be achieved by the lepton family asymmetries of heavy Majorana neutrino decays and how the lepton family asymmetries are related to CP violation in neutrino oscillation, in the minimal seesaw model with two heavy Majorana neutrinos. We derive the most general formula for CP violation in neutrino oscillation in terms of the heavy Majorana masses and Yukawa mass term. It is shown that the formula is very useful to classify several models in which e, {mu}, and {tau} leptogenesis can be separately realized and to see how they are connected with low energy CP violation. To make the models predictive, we take texture with two zeros in the Dirac matrix. In particular, we find some interesting cases in which CP violation in neutrino oscillation can happen while lepton family asymmetries do not exist at all. On the contrary, we can find e-, {mu}-, and {tau}-leptogenesis scenarios in which the cosmological CP violation and low energy CP violation measurable via neutrino oscillations are very closely related to each other. By determining the allowed ranges of the parameters in the models, we predict the sizes of CP violation in neutrino oscillation and vertical bar V{sub e3}{sup MNS} vertical bar. Finally, the leptonic unitarity triangles are reconstructed.

• OSTI ID: 20711086
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 1 Vol. 72; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ASYMMETRY
BARYONS
COSMOLOGY
CP INVARIANCE
ELECTRONS
MUONS
NEUTRINO OSCILLATION
NEUTRINOS
PARTICLE DECAY
PARTICLE PRODUCTION
REST MASS
TAU PARTICLES
UNITARITY