Vanishing of the CP asymmetry in leptogenesis due to form dominance

Journal Article · Sun Aug 01 00:00:00 EDT 2010 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.82.033002· OSTI ID:21432831

Choubey, Sandhya; Mitra, Manimala ^[1]; King, S F ^[2]

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1. Harish-Chandra Research Institute, Chhatnag Road, Jhunsi, 211019 Allahabad (India)
2. School of Physics and Astronomy, University of Southampton, SO17 1BJ Southampton (United Kingdom)

We emphasize that the vanishing of the CP asymmetry in leptogenesis, previously observed for models with tribimaximal mixing and family symmetry, may be traced to a property of the type I seesaw mechanism satisfied by such models known as form dominance, corresponding to the case of a diagonal Casas-Ibarra R-matrix. Form dominance leads to vanishing flavor-dependent CP asymmetries irrespective of whether one has tribimaximal mixing or a family symmetry. Successful leptogenesis requires violation of form dominance, but not necessarily violation of tribimaximal mixing. This may be achieved in models where the family symmetry responsible for tribimaximal mixing is implemented indirectly and a strong neutrino mass hierarchy is present with the form dominance broken only softly by the right-handed neutrino responsible for the lightest neutrino mass, as in constrained sequential dominance.

• OSTI ID: 21432831
• Journal Information: Physical Review. D, Particles Fields, Vol. 82, Issue 3; Other Information: DOI: 10.1103/PhysRevD.82.033002; (c) 2010 American Institute of Physics; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ASYMMETRY
CP INVARIANCE
FLAVOR MODEL
MASS
MIXING
NEUTRINOS
PARTICLE PRODUCTION
R MATRIX
SYMMETRY
SYMMETRY BREAKING
COMPOSITE MODELS
ELEMENTARY PARTICLES
FERMIONS
INVARIANCE PRINCIPLES
LEPTONS
MASSLESS PARTICLES
MATHEMATICAL MODELS
MATRICES
PARTICLE MODELS
QUARK MODEL