Tuesday, February 21, 2012

1202.4024 (P. M. Ferreira et al.)

Texture-zero model for the lepton mass matrices    [PDF]

P. M. Ferreira, L. Lavoura
We suggest a simple model, based on the type-I seesaw mechanism, for the
lepton mass matrices. The model hinges on an Abelian symmetry which leads to
mass matrices with some vanishing matrix elements. The model predicts one
massless neutrino and $M_{e\mu} = 0$ ($M$ is the effective light-neutrino
Majorana mass matrix). We show that these predictions perfectly agree with the
present experimental data if the neutrino mass spectrum is inverted, i.e. if
$m_3 = 0$, provided the Dirac phase $\delta$ is very close to maximal ($\pm \pi
/ 2$). In the case of a normal neutrino mass spectrum, i.e. when $m_1 = 0$, the
agreement of our model with the data is less than optimal---the reactor mixing
angle $\theta_{13}$ is too small in our model. Minimal leptogenesis is not an
option in our model due to the vanishing elements in the Yukawa-coupling
matrices.
View original: http://arxiv.org/abs/1202.4024

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