scholarly journals Grand unification models from SO(32) heterotic string

2020 ◽  
Vol 35 (32) ◽  
pp. 2050198
Author(s):  
Jihn E. Kim
Keyword(s):  
Symmetry Breaking ◽  
Gauge Group ◽  
Heterotic String ◽  
Grand Unification ◽  
Yukawa Couplings ◽  
Supersymmetric Version ◽  
Phenomenological Studies ◽  
Visible Sector ◽  
Tensor Representations ◽  
Spinor Representations

Grand unification groups (GUTs) are constructed from SO(32) heterotic string via [Formula: see text] orbifold compactification. So far, most phenomenological studies from string compactification relied on [Formula: see text] heterotic string, and this invites the SO(32) heterotic string very useful for future phenomenological studies. Here, spontaneous symmetry breaking is achieved by Higgsing of the antisymmetric tensor representations of SU[Formula: see text]. The anti-SU[Formula: see text] presented in this paper is a completely different class from the flipped-SU[Formula: see text]’s from the spinor representations of SO[Formula: see text]. Here, we realize chiral representations: [Formula: see text] for a SU(9) GUT and [Formula: see text] for a SU(5)[Formula: see text] GUT. In particular, we confirm that the non-Abelian anomalies of SU(9) gauge group vanish and hence our compactification scheme achieves the key requirement. We also present the Yukawa couplings, in particular for the heaviest fermion, [Formula: see text], and lightest fermions, neutrinos. In the supersymmetric version, we present a scenario how supersymmetry can be broken dynamically via the confining gauge group SU(9). Three families in the visible sector are interpreted as the chiral spectra of SU[Formula: see text] GUT.

SYMMETRY BREAKDOWN AND HIGHER-DIMENSIONAL MONOPOLES

1991 ◽  
Vol 06 (24) ◽  
pp. 2205-2209
Author(s):  
A. E. F. DJEMAI ◽  
M. TAHIRI
Keyword(s):  
Symmetry Breaking ◽  
Spontaneous Symmetry Breaking ◽  
Gauge Group ◽  
Dimensional Space ◽  
Magnetic Monopoles ◽  
Space Time ◽  
Grand Unification ◽  
Symmetry Breakdown ◽  
Higher Dimensional ◽  
Dimensional Space Time

In this work, we purpose to investigate the various topological conditions imposed on d-dimensional space-time, Grand Unification gauge group and on spontaneous symmetry breaking, which guarantee the existence of magnetic monopoles.

scholarly journals Hierarchical structure of physical Yukawa couplings from matter field Kähler metric

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Keiya Ishiguro ◽  
Tatsuo Kobayashi ◽  
Hajime Otsuka
Keyword(s):  
String Theory ◽  
Hierarchical Structure ◽  
Matter Field ◽  
Heterotic String ◽  
Heterotic String Theory ◽  
Kähler Metric ◽  
Yukawa Couplings ◽  
String Compactifications ◽  
Kahler Metric ◽  
Matter Fields

Abstract We study the impacts of matter field Kähler metric on physical Yukawa couplings in string compactifications. Since the Kähler metric is non-trivial in general, the kinetic mixing of matter fields opens a new avenue for realizing a hierarchical structure of physical Yukawa couplings, even when holomorphic Yukawa couplings have the trivial structure. The hierarchical Yukawa couplings are demonstrated by couplings of pure untwisted modes on toroidal orbifolds and their resolutions in the context of heterotic string theory with standard embedding. Also, we study the hierarchical couplings among untwisted and twisted modes on resolved orbifolds.

Symmetry breaking and charge operator in SU(9) grand-unification models

1986 ◽  
Vol 33 (1) ◽  
pp. 260-272
Author(s):  
Kyungsik Kang ◽  
Chung Ku Kim ◽  
Jae Kwan Kim
Keyword(s):  
Symmetry Breaking ◽  
Grand Unification ◽  
Charge Operator

FLUX-BREAKING, CORRELATION FUNCTIONS, MODULI AND SELECTION RULES IN THE THREE-GENERATION N=2 MINIMAL HETEROTIC STRING COMPACTIFICATION

1991 ◽  
Vol 06 (28) ◽  
pp. 5017-5045 ◽  
Author(s):  
STEFAN F. CORDES ◽  
Y. KIKUCHI
Keyword(s):  
Correlation Functions ◽  
Heterotic String ◽  
Selection Rules ◽  
Yukawa Couplings ◽  
Text Model

We study the orbifolding of Gepner’s [Formula: see text] model. We characterize the massless spectrum, including the moduli, and compute Yukawa couplings among these states. We determine possible nonvanishing, nonrenormalizable terms via selection rules.

scholarly journals LHC Probes of TeV-Scale Scalars in SO(10) Grand Unification

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Ufuk Aydemir ◽  
Tanumoy Mandal
Keyword(s):  
Scalar Field ◽  
Gauge Symmetry ◽  
Symmetry Breaking ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Gluon Fusion ◽  
Grand Unification ◽  
Gauge Bosons ◽  
The Standard Model ◽  
Last Stage

We investigate the possibility of TeV-scale scalars as low energy remnants arising in the nonsupersymmetric SO(10) grand unification framework where the field content is minimal. We consider a scenario where the SO(10) gauge symmetry is broken into the gauge symmetry of the Standard Model (SM) through multiple stages of symmetry breaking, and a colored and hypercharged scalar χ picks a TeV-scale mass in the process. The last stage of the symmetry breaking occurs at the TeV-scale where the left-right symmetry, that is, SU(2)L⊗SU(2)R⊗U(1)B-L⊗SU(3)C, is broken into that of the SM by a singlet scalar field S of mass MS~1 TeV, which is a component of an SU(2)R-triplet scalar field, acquiring a TeV-scale vacuum expectation value. For the LHC phenomenology, we consider a scenario where S is produced via gluon-gluon fusion through loop interactions with χ and also decays to a pair of SM gauge bosons through χ in the loop. We find that the parameter space is heavily constrained from the latest LHC data. We use a multivariate analysis to estimate the LHC discovery reach of S into the diphoton channel.

scholarly journals ON FERMION ZERO MODES IN INSTANTON V - A MODELS WITH SPONTANEOUS SYMMETRY BREAKING

1994 ◽  
Vol 09 (08) ◽  
pp. 715-723
Author(s):  
KAMRAN SARIRIAN
Keyword(s):  
Symmetry Breaking ◽  
Spontaneous Symmetry Breaking ◽  
Electroweak Theory ◽  
Yukawa Couplings ◽  
Zero Modes ◽  
Left Handed ◽  
Fermion Masses ◽  
Left And Right

The left- and right-handed fermion zero modes are examined. Their behavior under the variation of the size of the instanton, ρ I , and the size of the Higgs core, ρ H , for a range of Yukawa couplings corresponding to the fermion masses in the electroweak theory are studied. It is shown that the characteristic radii of the zero modes, in particular those of the left-handed fermions, are locked to the instanton size, and are not affected by the variation of ρ H , except for fermion masses much larger than those in the standard electroweak theory.

RADIATIVE EFFECTS AND ELECTROWEAK SYMMETRY BREAKING IN A SUPERSYMMETRIC PREON MODEL

1999 ◽  
Vol 14 (09) ◽  
pp. 1389-1427
Author(s):  
JONGBAE KIM
Keyword(s):  
Symmetry Breaking ◽  
Dynamical Symmetry ◽  
Electroweak Symmetry Breaking ◽  
Effective Theory ◽  
Supersymmetric Particle ◽  
Electroweak Symmetry ◽  
Radiative Effects ◽  
Yukawa Couplings ◽  
Lepton Universality

We construct the low energy effective theory of composite quarks, leptons, and Higgs bosons for a supersymmetric preon model and study the effects of renormalization-group based radiative corrections. The study on the evolution of scalar masses for avoiding color and charge breakings leads us to conclude that Yukawa couplings are bounded from above. The implementation of electroweak symmetry breaking requires that only the purely dynamical symmetry breaking should be needed for the model, but the combined scheme of dynamical and radiative symmetry breaking as well as the purely radiative symmetry breaking scheme be disfavored. Our analysis of [Formula: see text] including radiative effects shows that, should a discrepancy be found between the observed and the theoretical value of [Formula: see text] after experimental determination of supersymmetric particle masses, it would imply that the complete quark–lepton universality in the supersymmetric preon model does not hold either for the Yukawa couplings, or for the condensates, or for both.

scholarly journals Holomorphic Yukawa couplings in heterotic string theory

2016 ◽  
Vol 2016 (1) ◽  
Author(s):  
Stefan Blesneag ◽  
Evgeny I. Buchbinder ◽  
Philip Candelas ◽  
Andre Lukas
Keyword(s):  
String Theory ◽  
Heterotic String ◽  
Heterotic String Theory ◽  
Yukawa Couplings

scholarly journals MINIMAL SUPERSTRING STANDARD MODEL: A REVIEW

2001 ◽  
Vol 16 (supp01c) ◽  
pp. 949-951 ◽  
Author(s):  
Gerald B. Cleaver
Keyword(s):  
Field Theory ◽  
Standard Model ◽  
Gauge Group ◽  
Effective Field Theory ◽  
Vacuum Expectation ◽  
Effective Field ◽  
Heterotic String ◽  
Expectation Values ◽  
String Solution

I review a heterotic-string solution in which the observable sector effective field theory just below the string scale reduces to that of the MSSM, with the standard observable gauge group being just SU(3)C × SU(2)L × U(1)Y and the SU(3)C × SU(2)L × U(1)Y - charged spectrum of the observable sector consisting solely of the MSSM spectrum. Associated with this model is a set of distinct flat directions of vacuum expectation values (VEVs) of fields that all produce solely the MSSM spectrum. Some of these directions only involve VEVs of non-Abelian singlet fields while others also contain VEVs of non-Abelian charged fields. The phenomenology of theses flat directions is summarized.

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