Quasidegenerate neutrinos and leptogenesis from L{sub {mu}}-L{sub {tau}}
- Michigan Center for Theoretical Physics, Department of Physics, University of Michigan, Ann Arbor, Michigan 48109 (United States) and Korea Institute for Advanced Study, 207-43 Cheongryangri-dong, Dongdaemun-gu, Seoul 130-012 (Korea, Republic of)
We provide a framework for quasidegenerate neutrinos consistent with a successful leptogenesis, based on the L{sub {mu}}-L{sub {tau}} flavor symmetry and its breaking pattern. In this scheme, a fine-tuning is needed to arrange the small solar neutrino mass splitting. Once it is ensured, the atmospheric neutrino mass splitting and the deviation from the maximal atmospheric mixing angle {delta}{theta}{sub 23} are driven by the same symmetry breaking parameter {lambda}{approx}0.1, and the reactor angle {theta}{sub 13} is predicted to be slightly smaller than {lambda} while the Dirac CP phase is generically of order one. Given that the pseudo-Dirac nature of right-handed neutrinos is protected from the flavor symmetry breaking, a small mass splitting can be generated radiatively. For moderate values of tan{beta}{approx}10, this allows for low-scale supersymmetric leptogenesis, overcoming a strong washout effect of the quasidegenerate light neutrinos and evading the gravitino overproduction.
- OSTI ID:
- 21027683
- Journal Information:
- Physical Review. D, Particles Fields, Vol. 76, Issue 5; Other Information: DOI: 10.1103/PhysRevD.76.053008; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
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