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Title: Thermal leptogenesis in extended supersymmetric seesaw model

Abstract

We consider an extended supersymmetric SO(10) seesaw model with only doublet Higgs scalars, in which neutrino masses are suppressed by the scale of D-parity violation. Leptogenesis can occur at the TeV scale through the decay of a singlet {sigma}, thereby avoiding the gravitino crisis. Washout of the asymmetry can be effectively suppressed by the absence of direct couplings of {sigma} to leptons.

Authors:
; ; ; ;  [1];  [2];  [3];  [4]
  1. Instituto de Fisica Corpuscular--C.S.I.C./Universitat de Valencia Campus de Paterna, Apt 22085, E-46071 Valencia (Spain)
  2. (United Kingdom)
  3. (Portugal)
  4. (India)
Publication Date:
OSTI Identifier:
20933193
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. D, Particles Fields; Journal Volume: 75; Journal Issue: 1; Other Information: DOI: 10.1103/PhysRevD.75.011701; (c) 2007 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; ASYMMETRY; HIGGS MODEL; MASS; NEUTRINOS; PARITY; PARTICLE DECAY; PARTICLE PRODUCTION; SO-10 GROUPS; SUPERSYMMETRY; TEV RANGE

Citation Formats

Hirsch, M., Valle, J. W. F., Malinsky, M., Romao, J. C., Sarkar, U., School of Physics and Astronomy, University of Southampton, SO16 1BJ Southampton, Departamento de Fisica and CFTP, Instituto Superior Tecnico Av. Rovisco Pais 1, 1049-001 Lisbon, and Physical Research Laboratory, Ahmedabad 380 009. Thermal leptogenesis in extended supersymmetric seesaw model. United States: N. p., 2007. Web. doi:10.1103/PHYSREVD.75.011701.
Hirsch, M., Valle, J. W. F., Malinsky, M., Romao, J. C., Sarkar, U., School of Physics and Astronomy, University of Southampton, SO16 1BJ Southampton, Departamento de Fisica and CFTP, Instituto Superior Tecnico Av. Rovisco Pais 1, 1049-001 Lisbon, & Physical Research Laboratory, Ahmedabad 380 009. Thermal leptogenesis in extended supersymmetric seesaw model. United States. doi:10.1103/PHYSREVD.75.011701.
Hirsch, M., Valle, J. W. F., Malinsky, M., Romao, J. C., Sarkar, U., School of Physics and Astronomy, University of Southampton, SO16 1BJ Southampton, Departamento de Fisica and CFTP, Instituto Superior Tecnico Av. Rovisco Pais 1, 1049-001 Lisbon, and Physical Research Laboratory, Ahmedabad 380 009. Mon . "Thermal leptogenesis in extended supersymmetric seesaw model". United States. doi:10.1103/PHYSREVD.75.011701.
@article{osti_20933193,
title = {Thermal leptogenesis in extended supersymmetric seesaw model},
author = {Hirsch, M. and Valle, J. W. F. and Malinsky, M. and Romao, J. C. and Sarkar, U. and School of Physics and Astronomy, University of Southampton, SO16 1BJ Southampton and Departamento de Fisica and CFTP, Instituto Superior Tecnico Av. Rovisco Pais 1, 1049-001 Lisbon and Physical Research Laboratory, Ahmedabad 380 009},
abstractNote = {We consider an extended supersymmetric SO(10) seesaw model with only doublet Higgs scalars, in which neutrino masses are suppressed by the scale of D-parity violation. Leptogenesis can occur at the TeV scale through the decay of a singlet {sigma}, thereby avoiding the gravitino crisis. Washout of the asymmetry can be effectively suppressed by the absence of direct couplings of {sigma} to leptons.},
doi = {10.1103/PHYSREVD.75.011701},
journal = {Physical Review. D, Particles Fields},
number = 1,
volume = 75,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}
  • We analyze leptogenesis in a supersymmetric triplet seesaw scenario that explains the observed neutrino masses, adopting a phenomenological approach where the decay branching ratios of the triplets and the amount of CP violation in its different decay channels are assumed as free parameters. We find that the solutions of the relevant Boltzmann equations lead to a rich phenomenology, in particular, much more complex compared to the nonsupersymmetric case, mainly due to the presence of an additional Higgs doublet. Several unexpected and counter-intuitive behaviors emerge from our analysis: the amount of CP violation in one of the decay channels can provemore » to be irrelevant to the final lepton asymmetry, leading to successful leptogenesis even in scenarios with a vanishing CP violation in the leptonic sector; gauge annihilations can be the dominant effect in the determination of the evolution of the triplet density up to very high values of its mass, leading anyway to a sizeable final lepton asymmetry, which is also a growing function of the washout parameter K{identical_to}{gamma}{sub d}/H, defined as usual as the ratio between the triplet decay amplitude {gamma}{sub d} and the Hubble constant H; on the other hand, cancellations in the Boltzmann equations may lead to a vanishing lepton asymmetry if in one of the decay channels both the branching ratio and the amount of CP violation are suppressed, but not vanishing. The present analysis suggests that in the supersymmetric triplet seesaw model successful leptogenesis can be attained in a wide range of scenarios, provided that an asymmetry in the decaying triplets can act as a lepton-number reservoir.« less
  • We reconsidered leptogenesis scenario from right-handed (s)neutrino produced by the decay of inflaton. Besides the well-investigated case that the neutrino decays instantaneously after the production, leptogenesis is possible if neutrino decays after it dominates the universe. In the latter case, right-handed (s)neutrino can decay either while it is relativistic or after it becomes non-relativistic. Especially, the first case has not been discussed seriously in literatures. Resultant lepton asymmetry and constraints from the gravitino problem are studied in broad parameter region, including all cases of this scenario. It is also shown how this leptogenesis scenario depends on the parameters, the inflatonmore » decay rate (the reheating temperature), the right-handed neutrino mass, the washout parameter, and the constraint from the gravitino problem. Leptogenesis from relativistic neutrino decay is interesting because both thermal and non-thermal gravitino problems can be relaxed.« less
  • We consider a variant of the seesaw mechanism by introducing extra singlet neutrinos and a singlet scalar boson, and show how low scale leptogenesis is successfully realized in this scenario. We examine whether the newly introduced neutral particles, either singlet Majorana neutrinos or singlet scalar bosons, can be dark matter candidates. We also discuss the implications of dark matter detection through scattering off the nucleus of the detecting material on our scenarios for dark matter. In addition, we study the implications for the search for invisible Higgs decay at the Large Hadron Collider, which may serve as a probe formore » our scenario for dark matter.« less
  • The framework of supersymmetric see-saw models are considered. The successful leptogenesis scenarios which are due to a decay of the right-handed neutrinos tends to require rather heavy right-handed neutrinos. On the other hand, a discrepancy of the anomalous magnetic moment of the muon reported between the experimental and theoretical results implies lighter supersymmetric particles. In the light of successful leptogenesis scenarios, this anomaly of the anomalous magnetic moment of the muon leads to sizable lepton-flavour violations. It is shown that for a hierarchical right-handed neutrino mass spectrum, {mu}{yields}e{gamma} is expected to be observed in near future experiments.
  • We explore the prospects of low-scale leptogenesis in a class of supersymmetric SO(10) models using extra singlet neutrinos (T{sub i}, i=1, 2, 3) and the Higgs representations 126{sub H}+ 126{sub H} as well as 16{sub H}+16{sub H}. A singlet neutrino, which we show can be as light as 10{sup 5}-10{sup 6} GeV, decays through its small mixings with right-handed (RH) neutrinos creating a lepton asymmetry which is explicitly shown to be flavor dependent. While the doublet vacuum expectation value in 16{sub H} triggers the generation of desired mixings, it also induces a large RH-triplet vacuum expectation value that breaks themore » left-right intermediate gauge symmetry and gives large right-handed neutrino masses. Manifest unification of gauge couplings and generation of heavy RH neutrino masses are achieved by purely renormalizable interactions. The canonical (Type-I) seesaw contributions to the light neutrino mass matrix cancel out while the Type-II seesaw contribution is negligible. Determining the parameters of the dominant inverse seesaw formula by using the underlying quark-lepton symmetry and neutrino oscillation data, we show how leptogenesis under the gravitino constraint is successfully implemented. New formulas for the decay rate and the asymmetry parameter are derived leading to baryon asymmetry within the observed range without invoking a resonant condition on RH neutrinos. The model is found to work for hierarchical as well as inverted hierarchical light neutrino masses. Testable predictions of the model are RH doubly charged Higgs bosons which may be leptophilic and accessible to the Tevatron, LHC or a linear collider. In a model-independent manner, the Drell-Yan pair production cross section at the Tevatron or LHC is shown to be bounded between 59%-79% of their left-handed counterparts with same mass. In contrast to single-step breaking supersymmetric grand unified theories, which predict a long proton lifetime for the decay p{yields}e{sup +{pi}0}, here this lifetime is substantially reduced, bringing it within one order of the current experimental limit.« less