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Related papers: Leptogenesis without CP Violation at Low Energies

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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

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

We study the exactly degenerate case for three lefthanded Majorana neutrinos building a general parametrization for the leptonic mixing matrix characterized by two angles and one CP violating phase and identify a weak-basis invariant…

High Energy Physics - Phenomenology · Physics 2017-08-23 G. C. Branco , M. N. Rebelo , J. I. Silva-Marcos

We study CP violation in the lepton sector in extended models with right-handed neutrinos, without and with left-right symmetry, and with arbitrary mass terms. We find the conditions which must be satisfied by the neutrino and charged…

High Energy Physics - Phenomenology · Physics 2016-08-15 F. del Aguila , M. Zrałek

In this paper, we carry out a systematic study of the sufficient and necessary conditions for CP conservation in the leptonic sector with massive Majorana neutrinos. In particular, the emphasis is placed on the number of CP-violating phases…

High Energy Physics - Phenomenology · Physics 2021-02-23 Bingrong Yu , Shun Zhou

Heavy Majorana neutrinos beyond the standard model can simultaneously explain the origin of tiny neutrino masses and matter-antimatter asymmetry in our Universe. The existence of heavy Majorana neutrinos will also lead to lepton number…

High Energy Physics - Phenomenology · Physics 2022-10-05 Peng-Cheng Lu , Zong-Guo Si , Zhe Wang , Xing-Hua Yang

The seesaw extension of the SM explains the tiny neutrino masses and it is accompanied by many CP violating phases. We study the case where all leptonic CP violation arises from the soft breaking in the heavy Majorana mass matrix. Parameter…

High Energy Physics - Phenomenology · Physics 2023-11-20 C. C. Nishi , J. I. Silva-Marcos

Assuming 3-neutrino mixing and massive Majorana neutrinos, we analyze the possibility of establishing the existence of CP-violation associated with Majorana neutrinos in the lepton sector i) by measuring of the effective Majorana mass |<m>|…

High Energy Physics - Phenomenology · Physics 2008-11-26 S. Pascoli , S. T. Petcov , W. Rodejohann

We construct a model in which neutrinos and anti-neutrinos acquire the same mass but slightly different energy dispersion relations.Despite CPT violation, spin-statistics is preserved. We find that leptogenesis can be easily explained…

High Energy Physics - Phenomenology · Physics 2011-09-28 Chiu Man Ho

Some models of leptogenesis involve a nearly-degenerate pair of heavy Majorana neutrinos $N_{1,2}$ whose masses can be small, $O({\rm GeV})$. There can be heavy-light neutrino mixing parametrized by $|B_{\ell N}|^2 = 10^{-5}$, which leads…

High Energy Physics - Phenomenology · Physics 2021-04-27 David London

We further study the "complementary" Ansatz, Tr$(M_\nu)$=0, for a prediagonal light Majorana type neutrino mass matrix. Previously, this was studied for the CP conserving case and the case where the two Majorana type CP violating phases…

High Energy Physics - Phenomenology · Physics 2009-11-10 Samina S. Masood , Salah Nasri , Joseph Schechter

We discuss leptonic mixing and CP violation at low and high energies, emphasizing possible connections between leptogenesis and CP violation at low energies, in the context of lepton flavour models. Furthermore we analyse weak basis…

High Energy Physics - Phenomenology · Physics 2009-11-10 Gustavo C. Branco , M. N. Rebelo

Soft supersymmetry breaking terms involving heavy singlet sneutrinos provide new sources of lepton number violation and of CP violation. In addition to the CP violation in mixing, investigated previously, we find that `soft leptogenesis'…

High Energy Physics - Phenomenology · Physics 2008-11-26 Yuval Grossman , Tamar Kashti , Yosef Nir , Esteban Roulet

I discuss some theoretical aspects of how to observe leptonic CP violation. It is divided into two parts, one for CP violation due to Majorana, and the other more conventional leptonic Kobayashi-Maskawa (KM) phases. In the first part, I…

High Energy Physics - Phenomenology · Physics 2008-11-26 Hisakazu Minakata

We study the relation between the Majorana neutrino mass matrices and the neutrinoless double beta decay when CP is not conserved. We give an explicit form of the decay rate in terms of a rephasing invariant quantity and demonstrate that in…

High Energy Physics - Phenomenology · Physics 2010-11-01 Patrick J. O'Donnell , Utpal Sarkar

In trying to answer the question in the title of my talk, I have argued on ground of naturalness that leptonic CP violation is very likely to exist both in the form of the Kobayashi-Maskawa type and the Majorana type phases. The latter part…

High Energy Physics - Phenomenology · Physics 2007-05-23 Hisakazu Minakata

We analyse within the "flavoured" leptogenesis scenario of baryon asymmetry generation, the interplay of the "low energy" CP-violation, originating from the PMNS neutrino mixing matrix $U$, and the "high energy" CP-violation which can be…

High Energy Physics - Phenomenology · Physics 2009-07-22 E. Molinaro , S. T. Petcov

We study mixing and CP violation of three left-handed Majorana neutrinos in the limit of exactly degenerate masses, identify the weak-basis invariant relevant for CP violation and show that the leptonic mixing matrix is parametrized only by…

High Energy Physics - Phenomenology · Physics 2009-10-31 G. C. Branco , M. N. Rebelo , J. I. Silva-Marcos

We analyze the scenario of baryogenesis through leptogenesis induced by the out-of-equilibrium decays of heavy Majorana neutrinos and pay special attention to CP violation. Extending a recently proposed resummation formalism for two-fermion…

High Energy Physics - Phenomenology · Physics 2014-11-17 Apostolos Pilaftsis

In the context of the minimal supersymmetric seesaw model, we study the implications of the current neutrino data for thermal leptogenesis, $\beta\beta_{0\nu}$ decay, and leptonic flavour- and CP-violating low-energy observables. We express…

High Energy Physics - Phenomenology · Physics 2009-09-11 John Ellis , Martti Raidal