scholarly journals THE MINIMAL TYPE-I SEESAW MODEL AND FLAVOR-DEPENDENT LEPTOGENESIS

2008 ◽  
Vol 23 (21) ◽  
pp. 3403-3407 ◽  
Author(s):  
ZHI-ZHONG XING ◽  
SHUN ZHOU
Keyword(s):  
Yukawa Coupling ◽  
Baryon Number ◽  
Type I ◽  
Neutrino Mixing ◽  
Coupling Matrix ◽  
Seesaw Model ◽  
Majorana Neutrinos ◽  
Minimal Type ◽  
Baryon Number Asymmetry

In this talk, we first give a brief review of the so-called minimal seesaw models and then concentrate on the minimal type-I seesaw model with two almost degenerate right-handed Majorana neutrinos of [Formula: see text]. A specific texture of the neutrino Yukawa coupling matrix is proposed to achieve the nearly tri-bimaximal neutrino mixing pattern. This ansatz predicts (1) θ23 = π/4, |δ| = π/2 and sin 2θ12 = (1 − 2tan2θ13)/3 in the m1 = 0 case; and (2) θ23 = π/4 and θ13 = 8 = 0 in the m3 = 0 case. In both cases, the cosmological baryon number asymmetry can be explained via the resonant leptogenesis mechanism. Finally, we demonstrate the significance of flavor-dependent effects in our leptogenesis scenario.

scholarly journals THE MINIMAL TYPE-II SEESAW MODEL AND FLAVOR-DEPENDENT LEPTOGENESIS

2008 ◽  
Vol 23 (21) ◽  
pp. 3412-3415
Author(s):  
SHU LUO ◽  
ZHI-ZHONG XING
Keyword(s):  
Neutrino Mass ◽  
Mass Matrix ◽  
Baryon Number ◽  
Majorana Neutrino ◽  
Type Ii ◽  
Neutrino Mixing ◽  
Seesaw Model ◽  
Mixing Matrix ◽  
Current Experimental Data ◽  
Minimal Type

Current experimental data allow the zero value for one neutrino mass, either m1 = 0 or m3 = 0. This observation implies that a realistic neutrino mass texture can be established by starting from the limit (a) m1 = m2 = 0 and m3 ≠ 0 or (b) m1 = m2 ≠ 0 and m3 = 0. In both cases, we may introduce a particular perturbation which ensures the resultant neutrino mixing matrix to be the tri-bimaximal mixing pattern or its viable variations. We find that it is natural to incorporate this kind of neutrino mass matrix in the minimal Type-II seesaw model with only one heavy right-handed Majorana neutrino N. We show that it is possible to account for the cosmological baryon number asymmetry in the m3 = 0 case via thermal leptogenesis, in which the CP-violating asymmetry of N decays is attributed to the electron flavor.

scholarly journals NEUTRINO MASSES, LEPTON FLAVOR MIXING AND LEPTOGENESIS IN THE MINIMAL SEESAW MODEL

2007 ◽  
Vol 16 (01) ◽  
pp. 1-50 ◽  
Author(s):  
WAN-LEI GUO ◽  
ZHI-ZHONG XING ◽  
SHUN ZHOU
Keyword(s):  
Beta Decay ◽  
Neutrino Mass ◽  
Mass Matrix ◽  
Majorana Neutrino ◽  
Double Beta Decay ◽  
Neutrino Mixing ◽  
Lepton Flavor ◽  
Seesaw Model ◽  
Flavor Mixing ◽  
Majorana Neutrinos

We present a review of neutrino phenomenology in the minimal seesaw model (MSM), an economical and intriguing extension of the Standard Model with only two heavy right-handed Majorana neutrinos. Given current neutrino oscillation data, the MSM can predict the neutrino mass spectrum and constrain the effective masses of the tritium beta decay and the neutrinoless double-beta decay. We outline five distinct schemes to parameterize the neutrino Yukawa-coupling matrix of the MSM. The lepton flavor mixing and baryogenesis via leptogenesis are investigated in some detail by taking account of possible texture zeros of the Dirac neutrino mass matrix. We derive an upper bound on the CP-violating asymmetry in the decay of the lighter right-handed Majorana neutrino. The effects of the renormalization-group evolution on the neutrino mixing parameters are analyzed, and the correlation between the CP-violating phenomena at low and high energies is highlighted. We show that the observed matter-antimatter asymmetry of the Universe can naturally be interpreted through the resonant leptogenesis mechanism at the TeV scale. The lepton-flavor-violating rare decays, such as μ→e+γ, are also discussed in the supersymmetric extension of the MSM.

scholarly journals The Nature of Massive Neutrinos

2013 ◽  
Vol 2013 ◽  
pp. 1-20 ◽  
Author(s):  
S. T. Petcov
Keyword(s):  
Neutrino Mass ◽  
Current Data ◽  
Future Research ◽  
Type I ◽  
Neutrino Mixing ◽  
Mass Generation ◽  
Triplet Model ◽  
Majorana Neutrinos ◽  
Massive Neutrinos ◽  
Neutrino Mass Generation

The compelling experimental evidences for oscillations of solar, reactor, atmospheric, and accelerator neutrinos imply the existence of 3-neutrino mixing in the weak charged lepton current. The current data on the 3-neutrino mixing parameters are summarised and the phenomenology of 3-νmixing is reviewed. The properties of massive Majorana neutrinos and of their various possible couplings are discussed in detail. Two models of neutrino mass generation with massive Majorana neutrinos—the type I see-saw and the Higgs triplet model—are briefly reviewed. The problem of determining the nature, Dirac or Majorana, of massive neutrinos is considered. The predictions for the effective Majorana mass|〈m〉|in neutrinoless double-beta-((ββ)0ν-) decay in the case of 3-neutrino mixing and massive Majorana neutrinos are summarised. The physics potential of the experiments, searching for(ββ)0ν-decay for providing information on the type of the neutrino mass spectrum, on the absolute scale of neutrino masses, and on the Majorana CP-violation phases in the PMNS neutrino mixing matrix, is also briefly discussed. The opened questions and the main goals of future research in the field of neutrino physics are outlined.

scholarly journals Minimal type-I seesaw model with maximally restricted texture zeros

2018 ◽  
Vol 97 (11) ◽  
Author(s):  
D. M. Barreiros ◽  
R. G. Felipe ◽  
F. R. Joaquim
Keyword(s):  
Type I ◽  
Seesaw Model ◽  
Minimal Type

scholarly journals Aspects of high scale leptogenesis with low-energy leptonic CP violation

2021 ◽  
Vol 2021 (11) ◽  
Author(s):  
A. Granelli ◽  
K. Moffat ◽  
S. T. Petcov
Keyword(s):  
Cp Violation ◽  
Low Energy ◽  
Type I ◽  
Neutrino Mixing ◽  
High Scale ◽  
Boltzmann Equations ◽  
Majorana Neutrinos ◽  
Pmns Matrix ◽  
Neutrino Experiments ◽  
Majorana Phases

Abstract Using the density matrix equations (DME) for high scale leptogenesis based on the type I seesaw mechanism, in which the CP violation (CPV) is provided by the low-energy Dirac or/and Majorana phases of the neutrino mixing (PMNS) matrix, we investigate the 1-to-2 and the 2-to-3 flavour regime transitions, where the 1, 2 and 3 leptogenesis flavour regimes in the generation of the baryon asymmetry of the Universe ηB are described by the Boltzmann equations. Concentrating on the 1-to-2 flavour transition we determine the general conditions under which ηB goes through zero and changes sign in the transition. Analysing in detail the behaviour of ηB in the transition in the case of two heavy Majorana neutrinos N1,2 with hierarchical masses, M1 ≪ M2, we find, in particular, that i) the Boltzmann equations in many cases fail to describe correctly the generation of ηB in the 1, 2 and 3 flavour regimes, ii) the 2-flavour regime can persist above (below) ∼ 1012 GeV (∼ 109 GeV), iii) the flavour effects in leptogenesis persist beyond the typically considered maximal for these effects leptogenesis scale of 1012 GeV. We further determine the minimal scale M1min at which we can have successful leptogenesis when the CPV is provided only by the Dirac or Majorana phases of the PMNS matrix as well as the ranges of scales and values of the phases for having successful leptogenesis. We show, in particular, that when the CPV is due to the Dirac phase δ, there is a direct relation between the sign of sin δ and the sign of ηB in the regions of viable leptogenesis in the case of normal hierarchical light neutrino mass spectrum; for the inverted hierarchical spectrum the same result holds for M1 ≲ 1013 GeV. The considered different scenarios of leptogenesis are testable and falsifiable in low-energy neutrino experiments.

BIPAIR NEUTRINO MIXING AND LEPTOGENESIS

2013 ◽  
Vol 28 (07) ◽  
pp. 1350016 ◽  
Author(s):  
TERUYUKI KITABAYASHI
Keyword(s):  
Mass Matrix ◽  
Baryon Number ◽  
Neutrino Mixing ◽  
Lepton Asymmetry ◽  
Mixing Angle ◽  
Dirac Mass ◽  
Seesaw Model ◽  
Reactor Neutrino ◽  
The Universe

We estimate the baryon–photon ratio in the Universe via the leptogenesis scenario in the framework of the minimal seesaw model with a minimally modified bipair neutrino mixing. We assume that one of the elements of the 3 × 2 Dirac mass matrix mD is exactly zero. It turns out that the lepton asymmetry as well as baryon number of the Universe definitely depends on the reactor neutrino mixing angle in the cases of (mD)11 = 0 and (mD)12 = 0. The allowed region of the Majorana CP phase is separated into three regions related to the assumption of either (mD)11 = 0, (mD)21, 31 = 0 or (mD)12 = 0.

scholarly journals Complete one-loop matching of the type-I seesaw model onto the Standard Model effective field theory

2021 ◽  
Vol 2021 (9) ◽  
Author(s):  
Di Zhang ◽  
Shun Zhou
Keyword(s):  
Field Theory ◽  
Standard Model ◽  
Effective Field Theory ◽  
Mass Scale ◽  
Effective Field ◽  
Type I ◽  
Seesaw Model ◽  
The Standard Model ◽  
Majorana Neutrinos ◽  
The One

Abstract In this paper, we accomplish the complete one-loop matching of the type-I seesaw model onto the Standard Model Effective Field Theory (SMEFT), by integrating out three heavy Majorana neutrinos with the functional approach. It turns out that only 31 dimension-six operators (barring flavor structures and Hermitian conjugates) in the Warsaw basis of the SMEFT can be obtained, and most of them appear at the one-loop level. The Wilson coefficients of these 31 dimension-six operators are computed up to $$ \mathcal{O} $$ O (M−2) with M being the mass scale of heavy Majorana neutrinos. As the effects of heavy Majorana neutrinos are encoded in the Wilson coefficients of these higher-dimensional operators, a complete one-loop matching is useful to explore the low-energy phenomenological consequences of the type-I seesaw model. In addition, the threshold corrections to the couplings in the Standard Model and to the coefficient of the dimension-five operator are also discussed.

scholarly journals Radiative Corrections toMhfrom Three Generations of Majorana Neutrinos and Sneutrinos

2015 ◽  
Vol 2015 ◽  
pp. 1-26 ◽  
Author(s):  
S. Heinemeyer ◽  
J. Hernandez-Garcia ◽  
M. J. Herrero ◽  
X. Marcano ◽  
A. M. Rodriguez-Sanchez
Keyword(s):  
Higgs Boson ◽  
Higgs Mass ◽  
Critical Discussion ◽  
Full Detail ◽  
Neutrino Masses ◽  
Type I ◽  
Radiative Corrections ◽  
Seesaw Mechanism ◽  
Three Generations ◽  
Majorana Neutrinos

We study the radiative corrections to the mass of the lightest Higgs boson of the MSSM from three generations of Majorana neutrinos and sneutrinos. The spectrum of the MSSM is augmented by three right handed neutrinos and their supersymmetric partners. A seesaw mechanism of type I is used to generate the physical neutrino masses and oscillations that we require to be in agreement with present neutrino data. We present a full one-loop computation of these Higgs mass corrections and analyze in full detail their numerical size in terms of both the MSSM and the new (s)neutrino parameters. A critical discussion on the different possible renormalization schemes and their implications, in particular concerning decoupling, is included.

scholarly journals Catalyzed baryogenesis

2021 ◽  
Vol 2021 (10) ◽  
Author(s):  
Yang Bai ◽  
Joshua Berger ◽  
Mrunal Korwar ◽  
Nicholas Orlofsky
Keyword(s):  
Standard Model ◽  
Equilibrium Condition ◽  
Direct Detection ◽  
Outer Wall ◽  
Baryon Number ◽  
Baryon Asymmetry ◽  
The Standard Model ◽  
Large Ball ◽  
Baryon Number Asymmetry ◽  
Ball Mass

Abstract A novel mechanism, “catalyzed baryogenesis”, is proposed to explain the observed baryon asymmetry in our universe. In this mechanism, the motion of a ball-like catalyst provides the necessary out-of-equilibrium condition, its outer wall has CP-violating interactions with the Standard Model particles, and its interior has baryon number violating interactions. We use the electroweak-symmetric ball model as an example of such a catalyst. In this model, electroweak sphalerons inside the ball are active and convert baryons into leptons. The observed baryon number asymmetry can be produced for a light ball mass and a large ball radius. Due to direct detection constraints on relic balls, we consider a scenario in which the balls evaporate, leading to dark radiation at testable levels.

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