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Related papers: Leptonic CP violation from the seesaw

200 papers

The relation between leptogenesis and CP violation at low energies is analyzed in detail in the framework of the minimal seesaw mechanism. Working, without loss of generality, in a weak basis where both the charged lepton and the…

High Energy Physics - Phenomenology · Physics 2008-11-26 G. C. Branco , R. Gonzalez Felipe , F. R. Joaquim , I. Masina , M. N. Rebelo , C. A. Savoy

In the vanilla type-I seesaw leptogenesis scenario, CP violation required to generate the lepton asymmetries in the heavy Majorana neutrino decays stem from complex Dirac-type Yukawa couplings. In this paper we explore the case in which…

High Energy Physics - Phenomenology · Physics 2023-01-25 D. M. Barreiros , H. B. Câmara , R. G. Felipe , F. R. Joaquim

The nonzero neutrino mass can be a signal for new physics beyond the standard model. To explain the tiny neutrino mass, we can extend the standard model with right-handed Majorana neutrinos in a low-scale seesaw mechanism, while the CP…

High Energy Physics - Phenomenology · Physics 2023-03-15 Peng-Cheng Lu , Zong-Guo Si , Zhe Wang , Xing-Hua Yang , Xin-Yi Zhang

We discuss a class of models in which CP is violated softly in a heavy sector adjoined to the standard model. Heavy-sector loops produce the observed CP violation in kaon physics, yielding a tiny and probably undetectable value for…

High Energy Physics - Phenomenology · Physics 2009-09-11 Howard Georgi , Sheldon L. Glashow

We numerically study the correlation between CP violation in the neutrino oscillations and baryogenesis in the seesaw model. In this study we get the heavy Majorana neutrino masses and lepton number asymmetries from their decays by fitting…

High Energy Physics - Phenomenology · Physics 2009-11-07 T. Endoh , T. Morozumi , A. Purwanto

We studied models of leptogenesis where three right-handed Majorana neutrinos are involved and the minimal-extended seesaw mechanism including an additional singlet field produces four light neutrinos. This study shows that the type of mass…

High Energy Physics - Phenomenology · Physics 2022-12-28 Ki-Young Jung , Kim Siyeon

We study neutrino masses and mixings based on the simplest SO(10) mass relations and the seesaw mechanism. We find that the requirement of large neutrino mixings determines the relative magnitude of the heavy Majorana neutrino masses in…

High Energy Physics - Phenomenology · Physics 2009-11-07 W. Buchmuller , D. Wyler

We study the CP violation effects from two types of neutrino mass matrices with (i) $(M_\nu)_{ee}=0$, and (ii) $(M_\nu)_{ee}=(M_\nu)_{e\mu}=0$, which can be realized by the high dimensional lepton number violating operators $\bar…

High Energy Physics - Phenomenology · Physics 2016-01-20 Chao-Qiang Geng , Da Huang , Lu-Hsing Tsai

We consider a scenario of Low Scale Seesaw where the masses of its heavy Majorana neutrinos are arranged in a pattern of three pairs of quasi degenerate ones, in the range of O(1-6 GeV). Since they can violate lepton number by two units,…

High Energy Physics - Phenomenology · Physics 2016-12-01 Gaston Moreno , Jilberto Zamora-Saa

It was commonly thought that the observation of low energy leptonic CP-violating phases would not automatically imply the existence of a baryon asymmetry in the leptogenesis scenario. This conclusion does not generically hold when the issue…

High Energy Physics - Phenomenology · Physics 2008-11-26 S. Pascoli , S. T. Petcov , A. Riotto

Neutrino oscillation data strongly support mu-tau symmetry as a good approximate flavor symmetry of the neutrino sector, which has to appear in any viable theory for neutrino mass-generation. The mu-tau breaking is not only small, but also…

High Energy Physics - Phenomenology · Physics 2015-03-13 Shao-Feng Ge , Hong-Jian He , Fu-Rong Yin

Leptonic CP violation is one of the most important topics in neutrino physics. CP violation in the neutrino sector is strongly related to the nature of neutrinos: whether they are Dirac or Majorana particles. In \cite{Popov:2021icg} we have…

High Energy Physics - Phenomenology · Physics 2023-02-14 Artem Popov , Alexander Studenikin

A seesaw mechanism is presented in the neutrino sector and a new phase of CP violation ($\alpha$) emerges in the interplay between the type-I and type-III seesaw schemes. This phase is inside the mixing term, and thus it cannot be rotated…

High Energy Physics - Phenomenology · Physics 2016-01-14 Edison T. Franco

In the minimal left-right symmetric model, there are only two intrinsic CP violating phases to account for all CP violation in both the quark and lepton sectors, if CP is broken spontaneously by the complex phases in the VEV's of the scalar…

High Energy Physics - Phenomenology · Physics 2009-11-10 Mu-Chun Chen , K. T. Mahanthappa

We reveal the origin of the CP violation required by the leptogenesis in variously popular seesaw models. Especially we clarify that in a pure type-I/III seesaw with two fermion singlets/triplets, a combined type-I+III seesaw with one…

High Energy Physics - Phenomenology · Physics 2017-01-23 Pei-Hong Gu

With the help of a block parametrization of the canonical seesaw flavor textures in terms of the Euler-like rotation angles and CP-violaing phases, we derive a general and explicit expression for the Jarlskog invariant of CP violation in…

High Energy Physics - Phenomenology · Physics 2023-08-09 Zhi-zhong Xing

In this work we study examples of hierarchical neutrino mass matrices inspired by family symmetries, compatible with experiments on neutrino oscillations, and for which there is a connection among the low energy CP violation phase…

High Energy Physics - Phenomenology · Physics 2009-11-10 L. Velasco-Sevilla

We describe a method that is used to reduce, significantly, the number of CP violating complex phases in the Yukawa parameters. With this Reduction of Complex Phases (RCP) we obtain only one CP violating complex phase in the case where the…

High Energy Physics - Phenomenology · Physics 2007-05-23 J. I. Silva-Marcos

Leptonic CP violation is one of the most important topics in neutrino physics. CP violation in the neutrino sector is strongly related to the nature of neutrinos: whether they are Dirac or Majorana particles. In \cite{Popov:2021icg} we have…

High Energy Physics - Phenomenology · Physics 2024-06-11 A. Popov , A. Studenikin

We consider a version of the low-scale type I seesaw mechanism for generating small neutrino masses, as an alternative to the standard seesaw scenario. It involves two right-handed (RH) neutrinos $\nu_{1R}$ and $\nu_{2R}$ having a Majorana…

High Energy Physics - Phenomenology · Physics 2018-04-27 J. T. Penedo , S. T. Petcov , Tsutomu T. Yanagida