Can One have Significant Deviations from Leptonic $3\times 3$ Unitarity in the Framework of Type I Seesaw Mechanism?

Nuno Rosa Agostinho; G. C. Branco; Pedro M. F. Pereira; M. N. Rebelo; J. I. Silva-Marcos

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arXiv · 1711.06229

Can One have Significant Deviations from Leptonic $3\times 3$ Unitarity in the Framework of Type I Seesaw Mechanism?

Nuno Rosa Agostinho·G. C. Branco·Pedro M. F. Pereira·M. N. Rebelo·J. I. Silva-Marcos

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Abstract

We address the question of deviations from $3\times 3$ unitarity of the leptonic mixing matrix showing that, contrary to conventional wisdom, one may have significant deviations from unitarity in the framework of type I seesaw mechanism. In order for this scenario to be feasible, at least one of the heavy neutrinos must have a mass at the TeV scale, while the other two may have much larger masses. We present specific examples where deviations from $3\times 3$ unitarity are sufficiently small to conform to all the present stringent experimental bounds but are sufficiently large to have the potential for being detectable at the next round of experiments.

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Nuno Rosa Agostinho, G. C. Branco, Pedro M. F. Pereira, M. N. Rebelo, J. I. Silva-Marcos. 2017-11-16. Can One have Significant Deviations from Leptonic $3\times 3$ Unitarity in the Framework of Type I Seesaw Mechanism?. https://arxiv.org/abs/1711.06229

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