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Related papers: Neutrino Data, CP violation and Cosmological Impli…

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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

Assuming only a hierarchical structure of the heavy Majorana neutrino masses and of the neutrino Dirac mass matrix m_D of the see-saw mechanism, we find that in order to produce the observed baryon asymmetry of the Universe via…

High Energy Physics - Phenomenology · Physics 2009-11-10 S. Pascoli , S. T. Petcov , W. Rodejohann

We consider leptogenesis in a left-right-symmetric seesaw scenario in which neutrino mass generation and leptogenesis are dominated by the type-II seesaw term. Motivated by grand unification, we assume that the neutrino Dirac mass matrix is…

High Energy Physics - Phenomenology · Physics 2021-09-29 Thomas Rink , Werner Rodejohann , Kai Schmitz

We consider left-right symmetric model with spontaneous CP-violation. The Lagrangian of this model is CP invariant and the Yukawa couplings are real. Due to spontaneous breaking of the gauge symmetry, some of the neutral Higgses acquire…

High Energy Physics - Phenomenology · Physics 2014-11-18 Narendra Sahu , S. Uma Sankar

The origin of neutrino masses can be simply attributed to a new scalar beyond the Standard Model. We demonstrate that leptogenesis can explain the baryon asymmetry of the universe already in such a minimal framework, where the electroweak…

High Energy Physics - Phenomenology · Physics 2025-08-06 Shinya Kanemura , Shao-Ping Li

It is well-known that for unflavored leptogenesis there is in general no connection between low and high energy CP violation. We stress that for a non-unitary lepton mixing matrix this may not be the case. We give an illustrative example…

High Energy Physics - Phenomenology · Physics 2009-12-15 Werner Rodejohann

The necessary complex structures needed for CP violation are not easy to generate and, indeed, CP can be a symmetry in higher dimensional theories. In 4-dimensions CP violation argues for the existence of a scalar sector and, in its…

High Energy Physics - Phenomenology · Physics 2007-05-23 R. D. Peccei

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 discuss how the cosmological baryon asymmetry can be achieved by the lepton family asymmetries of heavy Majorana neutrino decays and they are related to CP violation in neutrino oscillation, in the minimal seesaw model with two heavy…

High Energy Physics - Phenomenology · Physics 2008-11-26 T. Fujihara , S. Kaneko , S. Kang , D. Kimura , T. Morozumi , M. Tanimoto

We explore the theoretical constraints on the observable parameters of neutrino mixing on predictions for the leptonic Dirac CP-violating phase within a well-studied class of simple theoretical models that includes a single source of CP…

High Energy Physics - Phenomenology · Physics 2022-10-06 Lisa L. Everett , Raymundo Ramos , Ariel B. Rock , Alexander J. Stuart

An attractive explanation for non-zero neutrino masses and small matter antimatter asymmetry of the present Universe lies in "leptogenesis". At present the {\it size} of the lepton asymmetry is precisely known, while the {\it sign} is not…

High Energy Physics - Phenomenology · Physics 2008-11-26 Kaushik Bhattacharya , Narendra Sahu , Utpal Sarkar , Santosh K. Singh

We discuss the question of CP-violation in the effective Hamiltonian approach in models of leptogenesis through heavy right handed neutrino decays. We first formulate the problem in four component notation and then point out that before the…

High Energy Physics - Phenomenology · Physics 2009-10-31 Utpal Sarkar , R. Vaidya

We investigate a minimal extension of the Leptogenesis framework that simultaneously explains the observed baryon asymmetry and dark matter (DM) abundance through the decay of a heavy Majorana neutrino. In this scenario, CP violation arises…

High Energy Physics - Phenomenology · Physics 2026-04-22 Henry G. F. McKenna , Juri Smirnov , Martin Gorbahn

The cosmological matter-antimatter asymmetry can originate from CP-violating interactions of seesaw Majorana neutrinos via leptogenesis in the thermal phase of the early universe. Having the cosmological CP-phase for leptogenesis requires…

High Energy Physics - Phenomenology · Physics 2009-09-15 V. Barger , Duane A. Dicus , Hong-Jian He , Tianjun Li

We review the basic mechanisms of neutrino mass generation and the corresponding structure of the lepton mixing matrix. We summarize the status of three-neutrino oscillation parameters as determined from current observations, using…

High Energy Physics - Phenomenology · Physics 2009-11-13 Hiroshi Nunokawa , Stephen Parke , Jose W. F. Valle

Radiative corrections to neutrino mixing and CP violation are analyzed in the minimal seesaw model with two heavy right-handed neutrinos. We find that textures of the effective Majorana neutrino mass matrix are essentially stable against…

High Energy Physics - Phenomenology · Physics 2009-11-10 Jian-wei Mei , Zhi-zhong Xing

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

The tiny neutrino masses can be explained naturally by extending the standard model with right-handed Majorana neutrinos in low-scale seesaw mechanism, and the CP violation effect induced by Majorana phase is interesting and worth studying…

High Energy Physics - Phenomenology · Physics 2021-10-22 Peng-Cheng Lu , Zong-Guo Si , Zhe Wang , Xing-Hua Yang

We further study the previously proposed Ansatz, Tr(M)=0, for a prediagonal light Majorana type neutrino mass matrix. If CP violation is neglected this enables one to use the existing data on squared mass differences to estimate (up to a…

High Energy Physics - Phenomenology · Physics 2009-11-10 Salah Nasri , Joseph Schechter , Sherif Moussa

We revisit the generation of a matter-antimatter asymmetry in the minimal extension of the Standard Model with two singlet heavy neutral leptons (HNL) that can explain neutrino masses. We derive an accurate analytical approximation to the…

High Energy Physics - Phenomenology · Physics 2022-12-07 Pilar Hernandez , Jacobo Lopez-Pavon , Nuria Rius , Stefan Sandner