scholarly journals GRAND UNIFICATION USING A GENERALIZED YANG–MILLS THEORY

2000 ◽  
Vol 15 (03) ◽  
pp. 197-206 ◽  
Author(s):  
M. CHAVES ◽  
H. MORALES
Keyword(s):  
Maximal Subgroup ◽  
Covariant Derivative ◽  
Irreducible Representations ◽  
Grand Unification ◽  
Strong Interactions ◽  
Chiral Structure ◽  
Yang Mills ◽  
Grand Unified Theories ◽  
Unified Theories ◽  
Vector Bosons

Generalized Yang–Mills theories have a covariant derivative that employs both scalar and vector bosons. Here we show how grand unified theories of the electroweak and strong interactions can be constructed with them. In particular the SU (5) GUT can be obtained from SU (6) with SU (5)× U (1) as a maximal subgroup. The choice of maximal subgroup also determines the chiral structure of the theory. The resulting Lagrangian has only two terms, and only two irreducible representations are needed, one for fermions and another for bosons.

"Conference on 60 Years of Yang-Mills Gauge Field Theories"

2015 ◽  
Vol 04 (01) ◽  
pp. 22-23
Author(s):  
Lars Brink
Keyword(s):  
Symmetry Algebra ◽  
Local Symmetry ◽  
Physical Review ◽  
Gauge Field Theories ◽  
Strong Interactions ◽  
Prototype Model ◽  
Yang Mills ◽  
Vector Bosons ◽  
In The Beginning ◽  
Chen Ning Yang

In 1954 Prof. Chen Ning Yang spent some time at Brookhaven National Laboratories where he met Robert Mills. They decided to study an extension of Quantum Electro Dynamics, where the local symmetry, the gauge symmetry, was a non-abelian symmetry algebra, SU(2), with three vector bosons mediating the forces between a doublet of matter particles. The symmetry that the authors had in mind was the isotopic symmetry and hence this was a prototype model for the strong interactions between protons and neutrons. The mass of the vector bosons was zero classically and the authors speculated that that they might obtain masses during quantization. On 1 October 1954 the Yang-Mills paper was published in the Physical Review. It was criticized directly by Wolfgang Pauli and others who argued that the vector particles would be massless leading to long-range interactions that was in contradiction to the experimental facts about the strong interactions. The interest in the paper was not so strong in the beginning.

From the standard model to grand unification

1982 ◽  
Vol 304 (1482) ◽  
pp. 69-86 ◽  
Keyword(s):  
Structure Constant ◽  
Fine Structure Constant ◽  
Grand Unification ◽  
Quark Masses ◽  
Grand Unified Theories ◽  
The Standard Model ◽  
Unified Theories ◽  
Order Of Magnitude ◽  
Near Future ◽  
The Universe

This paper reviews the limitations o f the standard SU (3) x SU (2) x U (l) model and develops the philosophy of grand unification. Some simple grand unified theories are presented, and calculations made of the order of magnitude of the fine-structure constant a, as well as of sin 2 0 W and some quark masses. Predictions for nucleon decay and neutrino masses are then discussed; they may be observable in the near future. It is suggested that grand unified theories complex enough for the understanding of the baryon asymmetry of the Universe may also predict a neutron electric dipole moment large enough to be measured. Finally, some inadequacies of GUTs are mentioned.

Particle physicists’ candidates for dark matter

1986 ◽  
Vol 320 (1556) ◽  
pp. 475-485 ◽  
Keyword(s):  
Dark Matter ◽  
Big Bang ◽  
Strong Interactions ◽  
Grand Unified Theories ◽  
Unified Theories ◽  
Massive Neutrinos ◽  
Supersymmetric Particles ◽  
The Big Bang

A review is presented of the candidates for dark matter that arise in different particle theories. These include massive neutrinos and monopoles in grand unified theories, axions arising from attempts to explain cp conservation in the strong interactions, stable supersymmetric particles such as photinos, gravitinos or sneutrinos, and other possible stable relics from the Big Bang. Wherever possible, relations to laboratory information and possible experiments directly sensitive to the different dark-matter candidates are discussed.

scholarly journals Grand unified theories in cosmology

1982 ◽  
Vol 307 (1497) ◽  
pp. 121-140 ◽  
Keyword(s):  
Particle Physics ◽  
Baryon Number ◽  
Low Energy ◽  
Grand Unification ◽  
Neutrino Masses ◽  
Neutron Electric Dipole Moment ◽  
Grand Unified Theories ◽  
Baryon Decay ◽  
Unified Theories ◽  
New Interactions

This paper reviews grand unified theories and some of their possible applications to cosmology. The philosophy of grand unification to be followed is first developed, some low-energy tests described, and then expectations for new interactions causing baryon decay and neutrino masses are presented. The experimental situations concerning these two possibilities are briefly reviewed. A discussion is given of the possible relevance of baryon-number violating reactions in grand unified theories to understanding the problem of baryosynthesis, and a possible connection with the neutron electric dipole moment is mentioned. Possible interfaces between cosmology and particle physics involving neutrinos are mentioned.

Water, Water, Here and There

2018 ◽  
Author(s):  
Steven E. Vigdor
Keyword(s):  
Quark Mass ◽  
Mass Difference ◽  
Baryon Number ◽  
Electroweak Phase Transition ◽  
Hydrogen Burning ◽  
Quark Masses ◽  
Grand Unified Theories ◽  
Down Quark ◽  
Unified Theories ◽  
The Stability

Chapter 4 deals with the stability of the proton, hence of hydrogen, and how to reconcile that stability with the baryon number nonconservation (or baryon conservation) needed to establish a matter–antimatter imbalance in the infant universe. Sakharov’s three conditions for establishing a matter–antimatter imbalance are presented. Grand unified theories and experimental searches for proton decay are described. The concept of spontaneous symmetry breaking is introduced in describing the electroweak phase transition in the infant universe. That transition is treated as the potential site for introducing the imbalance between quarks and antiquarks, via either baryogenesis or leptogenesis models. The up–down quark mass difference is presented as essential for providing the stability of hydrogen and of the deuteron, which serves as a crucial stepping stone in stellar hydrogen-burning reactions that generate the energy and elements needed for life. Constraints on quark masses from lattice QCD calculations and violations of chiral symmetry are discussed.

scholarly journals Accidental SO(10) axion from gauged flavour

2020 ◽  
Vol 2020 (11) ◽  
Author(s):  
Luca Di Luzio
Keyword(s):  
Mass Window ◽  
High Quality ◽  
High Scale ◽  
Quality Problem ◽  
Axion Mass ◽  
Grand Unified Theories ◽  
Unified Theories ◽  
Canonical Dimension ◽  
General Perspective ◽  
Effective Operators

Abstract An accidental U(1) Peccei-Quinn (PQ) symmetry automatically arises in a class of SO(10) unified theories upon gauging the SU(3)f flavour group. The PQ symmetry is protected by the ℤ4 × ℤ3 center of SO(10) × SU(3)f up to effective operators of canonical dimension six. However, high-scale contributions to the axion potential posing a PQ quality problem arise only at d = 9. In the pre-inflationary PQ breaking scenario the axion mass window is predicted to be ma ∈ [7 × 10−8, 10−3] eV, where the lower end is bounded by the seesaw scale and the upper end by iso-curvature fluctuations. A high-quality axion, that is immune to the PQ quality problem, is obtained for ma ≳ 2 0.02 eV. We finally offer a general perspective on the PQ quality problem in grand unified theories.

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