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We study variations of the standard leptogenesis scenario that can arise if an additional mass scale related to the breaking of some new symmetry (as for example a flavor or the B-L symmetry) is present below the mass $M_{N_1}$ of the…

High Energy Physics - Phenomenology · Physics 2009-09-29 Diego Aristizabal Sierra , Marta Losada , Enrico Nardi

We review some recent results on the connection between CP violation at low energies and Leptogenesis in the framework of specific flavour structures for the fundamental leptonic mass matrices with zero textures.

High Energy Physics - Phenomenology · Physics 2017-08-23 M. N. Rebelo

It is shown that the hierarchical structure of the quark mass terms in the standard model suggests a new description of the flavor mixing. The latter is primarily a heavy quark mixing involving the t and b quarks, followed by a mixing…

High Energy Physics - Phenomenology · Physics 2010-04-06 H. Fritzsch , Z. Z. Xing

We revisit the thermal leptogenesis scenario in the type-I seesaw framework featuring three heavy Majorana neutrinos with a hierarchical mass spectrum. We focus on low energy observables, specifically the lightest neutrino mass…

High Energy Physics - Phenomenology · Physics 2025-07-21 Alessandro Granelli , Koichi Hamaguchi , Maura E. Ramirez-Quezada , Kengo Shimada , Juntaro Wada , Tatsuya Yokoyama

We study basis-independent structures in the Type-I seesaw mechanism for light Majorana neutrinos, assuming the canonical scenario with three heavy right-handed (sterile) neutrinos. Let $m_\nu$ denote the $3\times3$ mass matrix of light…

High Energy Physics - Phenomenology · Physics 2025-12-09 Jianlong Lu

In this topical review we argue that neutrino mass and mixing data motivates extending the Standard Model to include a non-Abelian discrete flavour symmetry in order to accurately predict the large leptonic mixing angles and CP violation.…

High Energy Physics - Phenomenology · Physics 2015-11-12 Stephen F. King

We phenomenologically build a neutrino mass matrix obeying $\mu-\tau$ symmetry with only two parameters, Cabibbo angle $(\lambda)$ and a flavour twister parameter $(\eta)$. For vanishing $\eta$, the model assumes TBM mixing. When…

High Energy Physics - Phenomenology · Physics 2013-04-09 Subhankar Roy , N. Nimai Singh

Within the framework of the left-right symmetric model (LRSM) and under the assumption of a diagonal Dirac neutrino mass matrix $M_{\rm D}$, this paper systematically investigates 20 types of three-zero textures in the Majorana neutrino…

High Energy Physics - Phenomenology · Physics 2026-03-27 Ding-Hui Xu , Zhen-hua Zhao , Tian-Rui Wang

The CP-violation necessary for the generation of the baryon asymmetry of the Universe in the "flavoured" leptogenesis scenario can arise from the "low energy" PMNS neutrino mixing matrix and/or from the "high energy" part of neutrino Yukawa…

High Energy Physics - Phenomenology · Physics 2009-09-16 E. Molinaro , S. T. Petcov

The two kinds of indirect CP violation in neutral meson systems are related, in the absence of new weak phases in decay. The result is a model-independent expression relating CP violation in mixing, CP violation in the interference of…

High Energy Physics - Phenomenology · Physics 2009-11-05 Alexander L. Kagan , Michael D. Sokoloff

In the first part of the talk, I review general properties of $SO(10)$-inspired leptogenesis. This high-scale leptogenesis scenario is based on the simple assumption that the neutrino Dirac mass matrix is not too different from the up quark…

High Energy Physics - Phenomenology · Physics 2026-04-28 Pasquale Di Bari

We apply the discrete S_3 flavor symmetry to both lepton and quark sectors of the standard model extended by introducing one Higgs triplet and realizing the type-II seesaw mechanism for finite neutrino masses. The resultant mass matrices of…

High Energy Physics - Phenomenology · Physics 2014-11-20 Zhi-zhong Xing , Deshan Yang , Shun Zhou

We present an S$_4$ flavour symmetric model within a minimal seesaw framework resulting in mass matrices that leads to TM$_1$ mixing. Minimal seesaw is realized by adding two right-handed neutrinos to the Standard Model. The model predicts…

High Energy Physics - Phenomenology · Physics 2021-12-22 Bikash Thapa , Ng. K. Francis

In SO(10) models with a vectorial fourth generation of down quarks and leptons, the structure of the neutrino Majorana and Dirac mass matrices generically coincide with those of up- and down-quarks, respectively. Then the small neutrino…

High Energy Physics - Phenomenology · Physics 2007-10-12 Sören Wiesenfeldt

We discuss the seesaw mechanism which includes the minimum number of parameters for successful leptogenesis and three neutrino oscillations in the spirit of Occam's razor. We show that models with two right-handed neutrinos with two texture…

High Energy Physics - Phenomenology · Physics 2015-06-05 Keisuke Harigaya , Masahiro Ibe , Tsutomu T. Yanagida

In this letter, we perform a perturbative analysis by the lightest singular value $m_{D1}$ of the Dirac mass matrix $m_{D}$ in the type-I seesaw mechanism. A mass relation $M_{1} = m_{D1}^{2}/ |(m_{\nu})_{11}|$ is obtained for the lightest…

High Energy Physics - Phenomenology · Physics 2023-08-09 Masaki J. S. Yang

We propose a complex extension of mixed $\mu\tau$ antisymmetry in the neutrino Majorana mass matrix $M_\nu$. This can be implemented in the Lagrangian by a generalized CP transformation (labeled by a mixing parameter $\theta$) on the…

High Energy Physics - Phenomenology · Physics 2019-02-27 Roopam Sinha , Probir Roy , Ambar Ghosal

We reformulate the canonical seesaw mechanism in the case that the electroweak gauge symmetry is unbroken, and show that it can "formally" work and allow us to derive an exact seesaw formula for the light and heavy Majorana neutrinos. We…

High Energy Physics - Phenomenology · Physics 2023-02-22 Zhi-zhong Xing

We consider a minimal condition that predicts the 1-3 lepton mixing angle $\theta_{13} \simeq \theta_{\rm C}/\sqrt{2}$ with $\theta_{\rm C}$ the Cabibbo angle, and give the improved prediction of $\theta_{13}$. In the case of normal mass…

High Energy Physics - Phenomenology · Physics 2016-01-19 Junpei Harada

A low energy non-unitary leptonic mixing matrix is a generic feature of many extensions of the Standard Model. In such a case, the task of future precision neutrino oscillation experiments is more ambitious than measuring the three mixing…

High Energy Physics - Phenomenology · Physics 2009-09-02 Stefan Antusch , Mattias Blennow , Enrique Fernandez-Martinez , Jacobo Lopez-Pavon