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Title: Low intermediate scales for leptogenesis in supersymmetric SO(10) grand unified theories

Abstract

A low intermediate scale within minimal supersymmetric SO(10) GUTs is a desirable feature to accommodate leptogenesis. We explore this possibility in models where the intermediate gauge symmetry breaks spontaneously by (a) doublet Higgs scalars and also (b) by triplets. In both scenarios, gauge coupling unification requires the scale of left-right symmetry breaking (M{sub R}) to be close to the unification scale. This will entail unnaturally small neutrino Yukawa couplings to avoid the gravitino problem and allow successful leptogenesis. We point out that any one of three options--threshold corrections due to the mass spectrum near the unification scale, gravity induced nonrenormalizable operators near the Planck scale, or presence of additional light Higgs multiplets--can permit unification along with much lower values of M{sub R} as required for leptogenesis. In the triplet model, independent of these corrections, we find a lower bound on the intermediate scale, M{sub R}>10{sup 9} GeV, arising from the requirement that the theory must remain perturbative at least up to the GUT scale. We show that in the doublet model M{sub R} can even be in the TeV region which, apart from permitting resonant leptogenesis, can be tested at LHC and ILC.

Authors:
;  [1];  [2];  [1];  [3]
  1. Harish-Chandra Research Institute, Jhunsi, Allahabad 211 019 (India)
  2. (India)
  3. Physical Research Laboratory, Ahmedabad 380 009 (India)
Publication Date:
OSTI Identifier:
21020297
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. D, Particles Fields; Journal Volume: 75; Journal Issue: 7; Other Information: DOI: 10.1103/PhysRevD.75.075003; (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; CERN LHC; CORRECTIONS; COUPLING; GAUGE INVARIANCE; GEV RANGE; GRAND UNIFIED THEORY; GRAVITATION; HIGGS BOSONS; HIGGS MODEL; MASS SPECTRA; NEUTRINOS; SCALARS; SO-10 GROUPS; SUPERSYMMETRY; SYMMETRY BREAKING; TEV RANGE; TRIPLETS

Citation Formats

Majee, Swarup Kumar, Raychaudhuri, Amitava, Department of Physics, University of Calcutta, 92 A.P.C. Road, Kolkata 700 009, Parida, Mina K., and Sarkar, Utpal. Low intermediate scales for leptogenesis in supersymmetric SO(10) grand unified theories. United States: N. p., 2007. Web. doi:10.1103/PHYSREVD.75.075003.
Majee, Swarup Kumar, Raychaudhuri, Amitava, Department of Physics, University of Calcutta, 92 A.P.C. Road, Kolkata 700 009, Parida, Mina K., & Sarkar, Utpal. Low intermediate scales for leptogenesis in supersymmetric SO(10) grand unified theories. United States. doi:10.1103/PHYSREVD.75.075003.
Majee, Swarup Kumar, Raychaudhuri, Amitava, Department of Physics, University of Calcutta, 92 A.P.C. Road, Kolkata 700 009, Parida, Mina K., and Sarkar, Utpal. Sun . "Low intermediate scales for leptogenesis in supersymmetric SO(10) grand unified theories". United States. doi:10.1103/PHYSREVD.75.075003.
@article{osti_21020297,
title = {Low intermediate scales for leptogenesis in supersymmetric SO(10) grand unified theories},
author = {Majee, Swarup Kumar and Raychaudhuri, Amitava and Department of Physics, University of Calcutta, 92 A.P.C. Road, Kolkata 700 009 and Parida, Mina K. and Sarkar, Utpal},
abstractNote = {A low intermediate scale within minimal supersymmetric SO(10) GUTs is a desirable feature to accommodate leptogenesis. We explore this possibility in models where the intermediate gauge symmetry breaks spontaneously by (a) doublet Higgs scalars and also (b) by triplets. In both scenarios, gauge coupling unification requires the scale of left-right symmetry breaking (M{sub R}) to be close to the unification scale. This will entail unnaturally small neutrino Yukawa couplings to avoid the gravitino problem and allow successful leptogenesis. We point out that any one of three options--threshold corrections due to the mass spectrum near the unification scale, gravity induced nonrenormalizable operators near the Planck scale, or presence of additional light Higgs multiplets--can permit unification along with much lower values of M{sub R} as required for leptogenesis. In the triplet model, independent of these corrections, we find a lower bound on the intermediate scale, M{sub R}>10{sup 9} GeV, arising from the requirement that the theory must remain perturbative at least up to the GUT scale. We show that in the doublet model M{sub R} can even be in the TeV region which, apart from permitting resonant leptogenesis, can be tested at LHC and ILC.},
doi = {10.1103/PHYSREVD.75.075003},
journal = {Physical Review. D, Particles Fields},
number = 7,
volume = 75,
place = {United States},
year = {Sun Apr 01 00:00:00 EDT 2007},
month = {Sun Apr 01 00:00:00 EDT 2007}
}
  • An attempt is made to fill in the particle-mass gap between the ordinary masses of a few hundred GeV and the grand unification mass of 10/sup 15/ GeV by incorporating two and three stages of spontaneous symmetry breaking in the various descents of SO(10) to the low-energy symmetry SU(2)/sub L/ x U(1) x SU(3)/sub c/. It is shown that intermediate masses of order 10/sup 10/ GeV can exist in the particle-mass gap. Values lower than 10/sup 10/ GeV can only be achieved at the expense of pushing the grand unifying mass to the Planck mass. Also similarities in the gaugemore » structure and differences in the Higgs-scalar and fermion representations of the SU(2)/sub L/ x SU(2)/sub R/ x SU(4)/sub c/-based Pati-Salam model and its synthesis into SO(10) are pointed out.« less
  • In grand unified theories (GUT`s) based on SO(10) all fermions of one generation are embedded in a single representation. As a result, the top quark, the bottom quark, and the {tau} lepton have a universal Yukawa coupling at the GUT scale. This implies a very large ratio of Higgs vacuum expectation values, tan{beta}{congruent}{ital m}{sub {ital t}}/{ital m}{sub {ital b}}. We analyze the naturalness of such a scenario quantitatively including all the relevant radiative corrections and find that, in minimal unified supergravity models with universal soft supersymmetry-breaking parameters at the GUT scale, the necessary amount of fine-tuning is excessive. The GUTmore » threshold correction to the universal Higgs boson mass parameter can significantly reduce the fine-tuning required for such large values of tan{beta}. We also point out that the top quark mass can play a crucial role in explaining the hierarchy between the SUSY-breaking scale and the electroweak scale and, hence, the naturalness of large values of tan{beta}.« less
  • A new procedure is developed which enables one to start from the quark and lepton mass and mixing data at the low scale and construct mass matrices that exhibit simple SO(10) structure at the supersymmetric-grand-unification scale. This approach is applied to the present data involving quark and charged lepton masses, the quark mixing matrix and the nonadiabatic solar neutrino and atmospheric neutrino depletion effects. In terms of just 12 model parameters suggested by the procedure for the 5 mass matrices, we can reproduce remarkably well all the masses and mixing parameters for the scenario considered.
  • We present a detailed study of the quark and lepton mass spectra in a SO(10) framework with one 10{sub H} and one 126{sub H} Higgs representations in the Yukawa sector. We consider in full generality the interplay between type I and type II seesaw for neutrino masses. We first perform a {chi}{sup 2} fit of fermion masses independent on the structure of the GUT Higgs potential and determine the regions of the parameter space that are preferred by the fermion mass sum rules. We then apply our study to the case of the minimal renormalizable SUSY SO(10) GUT with onemore » 10{sub H}, one 126{sub H}, one 126{sub H}, and one 210{sub H} Higgs representations. By requiring that proton decay bounds are fulfilled we identify a very limited area in the parameter space where all fermion data are consistently reproduced. We find that in all cases gauge coupling unification in the supersymmetric scenario turns out to be severely affected by the presence of lighter than GUT (albeit B-L conserving) states. We then conclusively show that the minimal supersymmetric SO(10) scenario here considered is not consistent with data. The fit of neutrino masses with type I and type II seesaws within a renormalizable SO(10) framework strongly suggests a non-SUSY scenario for gauge unification.« less
  • We examine a superpotential for an SO(10) GUT and show that if the parameters of the superpotential are in a certain region, the SO(10) GUT has an intermediate symmetry SU(2){sub {ital L}}{circle_times}SU(2){sub {ital R}}{circle_times}SU(3){sub {ital C}}{circle_times}U(1){sub {ital B}{minus}{ital L}} which breaks down to the group of the standard model at an intermediate scale 10{sup 10}{endash}10{sup 12} GeV. In the model, by the breakdown of the symmetry, right-handed neutrinos acquire a mass of the intermediate scale through a renormalizable Yukawa coupling. {copyright} {ital 1996 The American Physical Society.}