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The Effective Lagrangian for the Seesaw Model of Neutrino Mass and Leptogenesis

A. Broncano·M. B. Gavela·E. Jenkins
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Abstract

The effective Lagrangian for the seesaw model is derived including effects due to CP violation. Besides the usual dimension-5 operator responsible for light neutrino masses, a dimension-6 operator is obtained. For three or less heavy neutrino generations, the inclusion of both operators is necessary and sufficient for all independent physical parameters of the high-energy seesaw Lagrangian to appear in the low-energy effective theory, including the CP-odd phases relevant for leptogenesis. The dimension-6 operator implies exotic low-energy couplings for light neutrinos, providing a link between the high-energy physics and low-energy observables.

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A. Broncano, M. B. Gavela, E. Jenkins. 2006-03-27. The Effective Lagrangian for the Seesaw Model of Neutrino Mass and Leptogenesis. https://doi.org/10.1016/j.physletb.2006.04.003

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