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Related papers: Dirac-Phase Thermal Leptogenesis in the extended T…

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We derive predictions for the Dirac phase $\delta$ present in the $3\times 3$ unitary neutrino mixing matrix $U = U_e^{\dagger} \, U_{\nu}$, where $U_e$ and $U_{\nu}$ are $3\times 3$ unitary matrices which arise from the diagonalisation,…

High Energy Physics - Phenomenology · Physics 2015-11-10 I. Girardi , S. T. Petcov , A. V. Titov

Effects of the lightest neutrino mass in "flavoured" leptogenesis when the CP-violation necessary for the generation of the baryon asymmetry of the Universe is due exclusively to the Dirac and/or Majorana phases in the neutrino mixing…

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

A model independent analysis of the leptonic Dirac CP-violating phase ({\delta}) is presented. The analysis uses the experimentally determined values of the mixing angles in the lepton mixing matrix in order to explore the allowed values…

High Energy Physics - Phenomenology · Physics 2014-06-09 J. Alberto Acosta , Alfredo Aranda , Julio Virrueta

In the present work we study both thermal and non-thermal leptogenesis in all neutrino mass models describing the presently available neutrino mass patterns. We consider the Majorana CP violating phases coming from right-handed Majorana…

High Energy Physics - Phenomenology · Physics 2008-07-16 N. Nimai Singh , H. Zeen Devi , Amal Kr Sarma

We consider leptogenesis induced by soft supersymmetry breaking terms ("soft leptogenesis"), in the context of the inverse seesaw mechanism. In this model there are lepton number (L) conserving and L-violating soft supersymmetry-breaking…

High Energy Physics - Phenomenology · Physics 2010-10-27 J. Garayoa , M. C. Gonzalez-Garcia , N. Rius

We propose a model for Dirac leptogenesis based on a non-anomalous $U(1)^{\prime}$ gauged family symmetry. The anomaly cancellation conditions are satisfied with no new chiral fermions other than the three right-handed neutrinos, giving…

High Energy Physics - Phenomenology · Physics 2012-11-21 Mu-Chun Chen , Jinrui Huang , William Shepherd

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

Models with composite singlet neutrinos can give small Majorana or Dirac masses to the active neutrinos. The mechanism is based on the fact that conserved chiral symmetries give massless neutrinos at the renormalizable level. Thus, they…

High Energy Physics - Phenomenology · Physics 2009-01-30 Yuval Grossman , Yuhsin Tsai

In the light of the $e^{+}+e^{-}$ excess observed by DAMPE experiment, we propose an anomaly-free radiative seesaw model with an alternative leptophilic $U(1)_X$ gauge symmetry. In the model, only right-handed leptons are charged under…

High Energy Physics - Phenomenology · Physics 2018-03-20 Zhi-Long Han , Weijian Wang , Ran Ding

We study the possibility of generating tiny Dirac neutrino masses at one loop level through the \textit{scotogenic} mechanism such that one of the particles going inside the loop can be a stable cold dark matter (DM) candidate. Majorana…

High Energy Physics - Phenomenology · Physics 2016-12-28 Debasish Borah , Arnab Dasgupta

In this paper, we perform a detail analysis on leptogenesis and dark matter form low scale seesaw. In the framework of $\nu$2HDM, we further introduce one scalar singlet $\phi$ and one Dirac fermion singlet $\chi$, which are charged under a…

High Energy Physics - Phenomenology · Physics 2020-05-13 Ang Liu , Zhi-Long Han , Yi Jin , Fa-Xin Yang

Low-scale seesaw variants protected by lepton number symmetry provide a natural explanation of the smallness of neutrino masses but, unlike their higher-scale counterparts, with potentially testable phenomenology. The approximate lepton…

High Energy Physics - Phenomenology · Physics 2023-03-29 Enrique Fernández-Martínez , Xabier Marcano , Daniel Naredo-Tuero

We classify the textures of the Dirac and the right-handed Majorana neutrino mass matrices, $M_D$ and $M_R$, which can satisfy the so-called ``Strong Scaling Ansatz'' (SSA) within the framework of the seesaw mechanism $M_{\nu}=-M_D^T…

High Energy Physics - Phenomenology · Physics 2007-12-24 Midori Obara

In leptogenesis scenario, the decays of heavy Majorana neutrinos generate lepton family asymmetries, $Y_e, Y_{\mu}$ and $Y_{\tau}$. They are sensitive to CP violating phases in seesaw models. The time evolution of the lepton family…

High Energy Physics - Phenomenology · Physics 2009-11-10 T. Endoh , T. Morozumi , Z. Xiong

We study in detail the mechanism of baryon and lepton asymmetry generation in the framework of the $\nu$MSM (an extension of the Standard Model by three singlet fermions with masses smaller than the electroweak scale). We elucidate the…

High Energy Physics - Phenomenology · Physics 2008-11-26 Mikhail Shaposhnikov

Heavy right handed neutrinos could not only explain the observed neutrino masses via the seesaw mechanism, but also generate the baryon asymmetry of the universe via leptogenesis due to their CP-violating interactions in the early universe.…

High Energy Physics - Phenomenology · Physics 2016-11-28 Marco Drewes , Bjorn Garbrecht , Dario Gueter , Juraj Klaric

We discuss leptogenesis constraints on the mass of the right-handed $W$-boson ($W_R$) in a TeV-scale Left-Right seesaw model (LRSM) for neutrino masses. For generic Dirac mass of the neutrinos, i.e. with all Yukawa couplings $\lesssim…

High Energy Physics - Phenomenology · Physics 2014-11-19 P. S. Bhupal Dev , Chang-Hun Lee , R. N. Mohapatra

It is well-known that leptogenesis in low energy scale is difficult in the conventional Type-I seesaw mechanism with hierarchical right-handed neutrino masses. We show that in a class of two Higgs doublet model, where one Higgs doublet…

High Energy Physics - Phenomenology · Physics 2011-07-03 Naoyuki Haba , Osamu Seto

The minimal gauged U(1)$_{L_\mu-L_\tau}$ model is a simple extension of the Standard Model and has a strong predictive power for the neutrino sector. In particular, the mass spectrum and couplings of heavy right-handed neutrinos are…

High Energy Physics - Phenomenology · Physics 2020-11-25 Kento Asai , Koichi Hamaguchi , Natsumi Nagata , Shih-Yen Tseng

We have investigated an approach for determining the Majorana type-phases using the time evolution of lepton family numbers. We show how the second-order time derivative of the expectation values for the lepton family numbers depends on the…

High Energy Physics - Phenomenology · Physics 2025-03-04 Nicholas J. Benoit , Yuta Kawamura , Saki Hamada , Takuya Morozumi , Yusuke Shimizu , Kei Yamamoto