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Title: Electroweak-scale resonant leptogenesis

Abstract

We study minimal scenarios of resonant leptogenesis near the electroweak phase transition. These models offer a number of testable phenomenological signatures for low-energy experiments and future high-energy colliders. Our study extends previous analyses of the relevant network of Boltzmann equations, consistently taking into account effects from out of equilibrium sphalerons and single lepton flavors. We show that the effects from single lepton flavors become very important in variants of resonant leptogenesis, where the observed baryon asymmetry in the Universe is created by lepton-to-baryon conversion of an individual lepton number, for example, that of the {tau}-lepton. The predictions of such resonant {tau}-leptogenesis models for the final baryon asymmetry are almost independent of the initial lepton-number and heavy neutrino abundances. These models accommodate the current neutrino data and have a number of testable phenomenological implications. They contain electroweak-scale heavy Majorana neutrinos with appreciable couplings to electrons and muons, which can be probed at future e{sup +}e{sup -} and {mu}{sup +}{mu}{sup -} high-energy colliders. In particular, resonant {tau}-leptogenesis models predict sizable 0{nu}{beta}{beta} decay, as well as e- and {mu}-number-violating processes, such as {mu}{yields}e{gamma} and {mu}{yields}e conversion in nuclei, with rates that are within reach of the experiments proposed by the MEG and MECOmore » collaborations.« less

Authors:
;  [1]
  1. School of Physics and Astronomy, University of Manchester, Manchester M13 9PL (United Kingdom)
Publication Date:
OSTI Identifier:
20774417
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. D, Particles Fields; Journal Volume: 72; Journal Issue: 11; Other Information: DOI: 10.1103/PhysRevD.72.113001; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ABUNDANCE; ASYMMETRY; BARYONS; BOLTZMANN EQUATION; CONSERVATION LAWS; COSMOLOGY; ELECTRON-POSITRON INTERACTIONS; ELECTRONS; FLAVOR MODEL; GRAND UNIFIED THEORY; INCLUSIVE INTERACTIONS; INTERNAL CONVERSION; LEPTON NUMBER; MUON-MUON INTERACTIONS; MUONS; NEUTRINOS; PHASE TRANSFORMATIONS; TAU PARTICLES; UNIVERSE

Citation Formats

Pilaftsis, Apostolos, and Underwood, Thomas E.J. Electroweak-scale resonant leptogenesis. United States: N. p., 2005. Web. doi:10.1103/PhysRevD.72.113001.
Pilaftsis, Apostolos, & Underwood, Thomas E.J. Electroweak-scale resonant leptogenesis. United States. doi:10.1103/PhysRevD.72.113001.
Pilaftsis, Apostolos, and Underwood, Thomas E.J. Thu . "Electroweak-scale resonant leptogenesis". United States. doi:10.1103/PhysRevD.72.113001.
@article{osti_20774417,
title = {Electroweak-scale resonant leptogenesis},
author = {Pilaftsis, Apostolos and Underwood, Thomas E.J.},
abstractNote = {We study minimal scenarios of resonant leptogenesis near the electroweak phase transition. These models offer a number of testable phenomenological signatures for low-energy experiments and future high-energy colliders. Our study extends previous analyses of the relevant network of Boltzmann equations, consistently taking into account effects from out of equilibrium sphalerons and single lepton flavors. We show that the effects from single lepton flavors become very important in variants of resonant leptogenesis, where the observed baryon asymmetry in the Universe is created by lepton-to-baryon conversion of an individual lepton number, for example, that of the {tau}-lepton. The predictions of such resonant {tau}-leptogenesis models for the final baryon asymmetry are almost independent of the initial lepton-number and heavy neutrino abundances. These models accommodate the current neutrino data and have a number of testable phenomenological implications. They contain electroweak-scale heavy Majorana neutrinos with appreciable couplings to electrons and muons, which can be probed at future e{sup +}e{sup -} and {mu}{sup +}{mu}{sup -} high-energy colliders. In particular, resonant {tau}-leptogenesis models predict sizable 0{nu}{beta}{beta} decay, as well as e- and {mu}-number-violating processes, such as {mu}{yields}e{gamma} and {mu}{yields}e conversion in nuclei, with rates that are within reach of the experiments proposed by the MEG and MECO collaborations.},
doi = {10.1103/PhysRevD.72.113001},
journal = {Physical Review. D, Particles Fields},
number = 11,
volume = 72,
place = {United States},
year = {Thu Dec 01 00:00:00 EST 2005},
month = {Thu Dec 01 00:00:00 EST 2005}
}
  • We study resonant leptogenesis at the electroweak phase transition in the singlet Majoron model with right-handed neutrinos. We consider a scenario where the SM gauge group and the lepton number break down spontaneously during a second-order electroweak phase transition. We calculate the flavor- and temperature-dependent leptonic asymmetries, by including the novel contributions from the transverse polarizations of the W{sup {+-}} and Z bosons. The required resummation of the gauge-dependent, off-shell, heavy-neutrino self-energies is consistently treated within the gauge-invariant framework of the pinch technique. Taking into consideration the freeze-out dynamics of sphalerons, we delineate the parameter space of the model thatmore » is compatible with successful electroweak resonant leptogenesis. The phenomenological and astrophysical implications of the model are discussed.« less
  • We consider a minimal extension of the standard model with one singlet neutrino per generation that can realize resonant leptogenesis at the electroweak scale. In particular, the baryon asymmetry in the Universe can be created by lepton-to-baryon conversion of an individual lepton number, for example, that of the {tau} lepton. The current neutrino data can be explained by a simple CP-violating Yukawa texture. The model has several testable phenomenological implications. It contains heavy Majorana neutrinos at the electroweak scale, which can be probed at e{sup +}e{sup -} linear colliders, and predicts e- and {mu}-lepton-number-violating processes, such as 0{nu}{beta}{beta} decay, {mu}{yields}e{gamma},more » and {mu}-e conversion in nuclei, with rates that are within reach of experimental sensitivity.« less
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  • In the presence of large extra dimensions, the fundamental scale could be as low as a few TeV. This yields leptogenesis and seesaw at a TeV scale. Phenomenologically, two TeV-scale Majorana fermions with a small mass split can realize a resonant leptogenesis, whereas a TeV-scale Higgs triplet with a small trilinear coupling to the standard model Higgs doublet can give a verifiable seesaw. We propose an interesting scenario where the small parameters for the resonant leptogenesis and the type-II seesaw can be simultaneously generated by the propagation of lepton number violation from distant branes to our world.