Physics – High Energy Physics – High Energy Physics - Phenomenology
Scientific paper
2008-10-17
Phys.Rev.D78:123527,2008
Physics
High Energy Physics
High Energy Physics - Phenomenology
Footnote added; Factor of 2 in the supersymmetric case corrected
Scientific paper
10.1103/PhysRevD.78.123527
Seesaw models with a slightly broken lepton number symmetry can explain small neutrino masses, and allow for low-scale leptogenesis. We make a thorough analysis of leptogenesis within the simplest model with two right-handed (RH) neutrinos (or with N_3 decoupled). We obtain a semi-analytical formula for the final asymmetry in both supersymmetric and non-supersymmetric cases with a simple dependence on each parameter. The low-energy parameters factorize from the high-energy ones, and the high-energy phase must be non-zero. The role of the PMNS phases is carefully studied. Moreover, we find that the breaking parameter in the Yukawa coupling matrix must be relatively large, \epsilon_h > 10^{-3} for normal and 10^{-2} for inverted hierarchy. Therefore, leptogenesis in our simple model is incompatible with RH neutrino signals at future colliders or sizable lepton-flavor violation. The other breaking parameter, \epsilon_M, which appears in the RH neutrino mass matrix, can be much smaller, and actually needs to be so in order to have low-scale leptogenesis.
Asaka Takehiko
Blanchet Steve
No associations
LandOfFree
Leptogenesis with an almost conserved lepton number does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Leptogenesis with an almost conserved lepton number, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Leptogenesis with an almost conserved lepton number will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-351567