scholarly journals Unification Yang–Mills Groups and Representations with CP as a Gauge Symmetry

1997 ◽  
Vol 12 (03) ◽  
pp. 557-584 ◽  
Author(s):  
Huazhong Zhang
Keyword(s):  
Gauge Symmetry ◽  
Model Building ◽  
Energy Spectra ◽  
Superstring Theory ◽  
Yang Mills ◽  
Physical Operator ◽  
The Standard Model ◽  
Low Energies ◽  
Inner Automorphism ◽  
Weyl Fermions

We investigate more generally the possible unification Yang–Mills groups G YM and representations with CP as a gauge symmetry. Besides the possible Yang–Mills groups E8, E7, SO (2n + 1), SO (4n), SP (2n), G2 or F4 (or a product of them) which only allow self-contragredient representations, we present other unification groups G YM and representations which may allow CP as a gauge symmetry. These include especially SU (N) containing Weyl fermions and their CP conjugates from low energy spectra in a basic irreducible representation (IR). Such an example is the 496-dimensional basic IR (on antisymmetric tensors of rank two) of SU (32) containing SO (32) as a subgroup in the adjoint IR, or SU (248) in a fundamental IR containing E8 as a subgroup in the adjoint IR. Our consideration also leads to the construction of a physical operator (CP) intrinsically as an inner automorphism of order higher than two for the unification group. We have also generalized the possible groups as unification G YM to include nonsemisimple Lie groups with CP arising as a gauge symmetry. In this case with U(1) ideals in the G YM , we found that the U Y(1) for weak hypercharge in the standard model or a U (1) gauge symmetry at low energies in general is traceless. Possible relevance to superstring theory is also briefly discussed. We expect that our results may open new alternatives for unified model building, especially with deeper or more generalized understanding of anomaly-free theories.

scholarly journals E6 inspired SUSY models with custodial symmetry

2018 ◽  
Vol 33 (31) ◽  
pp. 1844007 ◽  
Author(s):  
R. Nevzorov
Keyword(s):  
Gauge Symmetry ◽  
Standard Model ◽  
Supersymmetric Standard Model ◽  
Exotic States ◽  
Grand Unified Theories ◽  
The Standard Model ◽  
Unified Theories ◽  
Low Energies ◽  
Custodial Symmetry ◽  
Susy Models

The breakdown of [Formula: see text] within the supersymmetric (SUSY) Grand Unified Theories (GUTs) can result in SUSY extensions of the standard model (SM) based on the SM gauge group together with extra [Formula: see text] gauge symmetry under which right-handed neutrinos have zero charge. In these [Formula: see text] extensions of the minimal supersymmetric standard model (MSSM) a single discrete [Formula: see text] symmetry may be used to suppress the most dangerous operators, that give rise to proton decay as well as nondiagonal flavour transitions at low energies. The SUSY models under consideration involves [Formula: see text] and extra exotic matter beyond the MSSM. We discuss leptogenesis within this SUSY model and argue that the extra exotic states may lead to the nonstandard Higgs decays.

SYMMETRY RESTORATION IN THE SUPERSTRING THEORY

2002 ◽  
Vol 11 (03) ◽  
pp. 311-319 ◽  
Author(s):  
M. D. POLLOCK
Keyword(s):  
Gauge Symmetry ◽  
Gauge Group ◽  
Low Temperatures ◽  
Scalar Potential ◽  
Potential Drop ◽  
Scalar Fields ◽  
Superstring Theory ◽  
The Standard Model ◽  
The Right ◽  
Standard Model Gauge Group

The grand unified gauge group G 6≡ SU (3) C × SU (3) L × SU (3) R , which results from compactification of the heterotic superstring onto a three-generation Calabi–Yau space as a maximal subgroup of E 6, contains two superfields, whose scalar components are the conjugates neutrino [Formula: see text] and the neutral Higgs N, which are singlets of the standard-model gauge group G 4≡ SU (3) C × SU (2) L × U (1) Y , and which therefore break G 6to G 4 when they acquire non-vanishing vacuum expectative values. Here, we show how this process can be implemented in two steps when the scalar potential V(ϕi) is chosen along a non-D-flat direction, using the "superconducting" model due to Mohapatra and Senjanović, in which one of two scalar fields remains in the asymmetric state up to a temperature T0~ 1017 GeV , above which the kinetic energy exceeds the potential drop, forcing restoration of the symmetry below the compactification scale T c ≈ 1017 GeV . This implies that [Formula: see text] initially, but at low temperatures T ≪ M w , we find that [Formula: see text], thus avoiding the problems associated with large intermediate scales M I ≳ 109 GeV while keeping the Higgs mixing term ~ NH1H2 at the right level. A discrete gauge symmetry can prevent the proton from decaying too rapidly.

scholarly journals New modular invariants in $$ \mathcal{N} $$ = 4 Super-Yang-Mills theory

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Shai M. Chester ◽  
Michael B. Green ◽  
Silviu S. Pufu ◽  
Yifan Wang ◽  
Congkao Wen
Keyword(s):  
Eisenstein Series ◽  
Mass Parameter ◽  
Flat Space ◽  
Superstring Theory ◽  
Modular Invariant ◽  
Yang Mills ◽  
Laplace Eigenvalue ◽  
Modular Invariants ◽  
Tensor Multiplet ◽  
Super Yang Mills Theory

Abstract We study modular invariants arising in the four-point functions of the stress tensor multiplet operators of the $$ \mathcal{N} $$ N = 4 SU(N) super-Yang-Mills theory, in the limit where N is taken to be large while the complexified Yang-Mills coupling τ is held fixed. The specific four-point functions we consider are integrated correlators obtained by taking various combinations of four derivatives of the squashed sphere partition function of the $$ \mathcal{N} $$ N = 2∗ theory with respect to the squashing parameter b and mass parameter m, evaluated at the values b = 1 and m = 0 that correspond to the $$ \mathcal{N} $$ N = 4 theory on a round sphere. At each order in the 1/N expansion, these fourth derivatives are modular invariant functions of (τ,$$ \overline{\tau} $$ τ ¯ ). We present evidence that at half-integer orders in 1/N , these modular invariants are linear combinations of non-holomorphic Eisenstein series, while at integer orders in 1/N, they are certain “generalized Eisenstein series” which satisfy inhomogeneous Laplace eigenvalue equations on the hyperbolic plane. These results reproduce known features of the low-energy expansion of the four-graviton amplitude in type IIB superstring theory in ten-dimensional flat space and have interesting implications for the structure of the analogous expansion in AdS5× S5.

scholarly journals Electroweak-like baryogenesis with new chiral matter

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Kohei Fujikura ◽  
Keisuke Harigaya ◽  
Yuichiro Nakai ◽  
Ruoquan Wang
Keyword(s):  
Phase Transition ◽  
Gauge Symmetry ◽  
Cp Violation ◽  
Standard Model ◽  
Dipole Moments ◽  
Dark Matter Candidate ◽  
Lepton Asymmetry ◽  
First Order ◽  
The Standard Model ◽  
Concrete Realization

Abstract We propose a framework where a phase transition associated with a gauge symmetry breaking that occurs (not far) above the electroweak scale sets a stage for baryogenesis similar to the electroweak baryogenesis in the Standard Model. A concrete realization utilizes the breaking of SU(2)R× U(1)X→ U(1)Y. New chiral fermions charged under the extended gauge symmetry have nonzero lepton numbers, which makes the B − L symmetry anomalous. The new lepton sector contains a large flavor-dependent CP violation, similar to the Cabibbo-Kobayashi-Maskawa phase, without inducing sizable electric dipole moments of the Standard Model particles. A bubble wall dynamics associated with the first-order phase transition and SU(2)R sphaleron processes generate a lepton asymmetry, which is transferred into a baryon asymmetry via the ordinary electroweak sphaleron process. Unlike the Standard Model electroweak baryogenesis, the new phase transition can be of the strong first order and the new CP violation is not significantly suppressed by Yukawa couplings, so that the observed asymmetry can be produced. The model can be probed by collider searches for new particles and the observation of gravitational waves. One of the new leptons becomes a dark matter candidate. The model can be also embedded into a left-right symmetric theory to solve the strong CP problem.

scholarly journals Heterotic line bundle models on generalized complete intersection Calabi Yau manifolds

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Magdalena Larfors ◽  
Davide Passaro ◽  
Robin Schneider
Keyword(s):  
Line Bundle ◽  
Complete Intersection ◽  
Particle Physics ◽  
Model Building ◽  
Wilson Line ◽  
Symmetry Groups ◽  
The Standard Model ◽  
Order Of Magnitude ◽  
Systematic Program ◽  
Calabi Yau Manifolds

Abstract The systematic program of heterotic line bundle model building has resulted in a wealth of standard-like models (SLM) for particle physics. In this paper, we continue this work in the setting of generalised Complete Intersection Calabi Yau (gCICY) manifolds. Using the gCICYs constructed in ref. [1], we identify two geometries that, when combined with line bundle sums, are directly suitable for heterotic GUT models. We then show that these gCICYs admit freely acting ℤ2 symmetry groups, and are thus amenable to Wilson line breaking of the GUT gauge group to that of the standard model. We proceed to a systematic scan over line bundle sums over these geometries, that result in 99 and 33 SLMs, respectively. For the first class of models, our results may be compared to line bundle models on homotopically equivalent Complete Intersection Calabi Yau manifolds. This shows that the number of realistic configurations is of the same order of magnitude.

scholarly journals ANOMALOUS U(1)A AND ELECTROWEAK SYMMETRY BREAKING

2001 ◽  
Vol 16 (13) ◽  
pp. 835-844
Author(s):  
ILIA GOGOLADZE ◽  
MIRIAN TSULAIA
Keyword(s):  
Gauge Symmetry ◽  
Standard Model ◽  
Symmetry Breaking ◽  
Supersymmetric Standard Model ◽  
Electroweak Symmetry Breaking ◽  
Electroweak Symmetry ◽  
Superstring Theory

We suggest a new mechanism for electroweak symmetry breaking in the supersymmetric Standard Model. Our suggestion is based on the presence of an anomalous U (1)A gauge symmetry, which naturally arises in the four-dimensional superstring theory, and heavily relies on the value of the corresponding Fayet–Illiopoulos ξ-term.

scholarly journals A REVIEW OF INTEGRABLE DEFORMATIONS IN AdS/CFT

2007 ◽  
Vol 22 (13) ◽  
pp. 915-930 ◽  
Author(s):  
IAN SWANSON
Keyword(s):  
String Theory ◽  
Bethe Ansatz ◽  
Energy Spectra ◽  
Yang Mills ◽  
Twisted String ◽  
Pp Wave ◽  
Integrable Deformations ◽  
Type Iib String Theory ◽  
Bethe Equations ◽  
Wave Limit

Marginal β deformations of [Formula: see text] super-Yang–Mills theory are known to correspond to a certain class of deformations of the S5 background subspace of type IIB string theory in AdS5×S5. An analogous set of deformations of the AdS5 subspace is reviewed here. String energy spectra computed in the near-pp-wave limit of these backgrounds match predictions encoded by discrete, asymptotic Bethe equations, suggesting that the twisted string theory is classically integrable in this regime. These Bethe equations can be derived algorithmically by relying on the existence of Lax representations, and on the Riemann–Hilbert interpretation of the thermodynamic Bethe ansatz. This letter is a review of a seminar given at the Institute for Advanced Study, based on research completed in collaboration with McLoughlin.

scholarly journals S-SAD phasing on SOLEIL Beamline PROXIMA 1

2014 ◽  
Vol 70 (a1) ◽  
pp. C609-C609
Author(s):  
Patrick Gourhant ◽  
Beatriz Guimaraes ◽  
Tatiana Isabet ◽  
Sebastian Klinke ◽  
Pierre Legrand ◽  
...  
Keyword(s):  
Model Building ◽  
De Novo ◽  
Signal To Noise Ratio ◽  
Beam Line ◽  
Synchrotron Source ◽  
Combining Data ◽  
Low Energies ◽  
Sad Phasing ◽  
Multiple Sample ◽  
Data Collections

"PROXIMA 1, a beamline for macro-molecular crystallography at the 3rd generation synchrotron source SOLEIL, is equipped with a multi-circle goniometer (alpha 50 degrees) as well as a PILATUS 6M detector. These features, along with the extended energy range of the beam line towards the low energies (down to 5.5 keV) and the possibility to adapt the source size to the sample in order to optimize signal to noise ratio, have made the beam line very attractive for S-SAD phasing with more than seven examples of successful de novo phasing achieved over the last two years. The use of low energies has also proved a significant aid in assisting with MODEL building. The technical capabilities of the beam line for low energy data collections will be presented, along with a number of examples of the successful use of low wavelengths on the beam line. The importance of combining data from multiple sample orientations in order to achieve ""true multiplicity"" will be highlighted, as well as the importance of combining data from multiple crystals in order to achieve high multiplicity."

A Clifford algebra-based grand unification program of gravity and the Standard Model: a review study

2014 ◽  
Vol 92 (12) ◽  
pp. 1501-1527 ◽  
Author(s):  
Carlos Castro
Keyword(s):  
Standard Model ◽  
Geometric Probability ◽  
Coupling Constants ◽  
Grand Unified Theory ◽  
Neutrino Mixing ◽  
Yang Mills ◽  
Bounded Complex ◽  
The Standard Model ◽  
Mixing Matrix ◽  
Homogeneous Domains

A Clifford Cl(5, C) unified gauge field theory formulation of conformal gravity and U(4) × U(4) × U(4) Yang–Mills in 4D, is reviewed along with its implications for the Pati–Salam (PS) group SU(4) × SU(2)L × SU(2)R, and trinification grand unified theory models of three fermion generations based on the group SU(3)C × SU(3)L × SU(3)R. We proceed with a brief review of a unification program of 4D gravity and SU(3) × SU(2) × U(1) Yang–Mills emerging from 8D pure quaternionic gravity. A realization of E8 in terms of the Cl(16) = Cl(8) ⊗ Cl(8) generators follows, as a preamble to F. Smith’s E8 and Cl(16) = Cl(8) ⊗ Cl(8) unification model in 8D. The study of chiral fermions and instanton backgrounds in CP2 and CP3 related to the problem of obtaining three fermion generations is thoroughly studied. We continue with the evaluation of the coupling constants and particle masses based on the geometry of bounded complex homogeneous domains and geometric probability theory. An analysis of neutrino masses, Cabbibo–Kobayashi–Maskawa quark-mixing matrix parameters, and neutrino-mixing matrix parameters follows. We finalize with some concluding remarks about other proposals for the unification of gravity and the Standard Model, like string, M, and F theories and noncommutative and nonassociative geometry.

scholarly journals Ontology in Quantum Mechanics

2021 ◽  
Author(s):  
Gerard ’t Hooft
Keyword(s):  
Hilbert Space ◽  
General Relativity ◽  
Black Hole ◽  
Quantum Mechanics ◽  
Evolution Equations ◽  
Black Hole Physics ◽  
Special Kind ◽  
Quantum Evolution ◽  
The Standard Model ◽  
Low Energies

It is suspected that the quantum evolution equations describing the micro-world as we know it are of a special kind that allows transformations to a special set of basis states in Hilbert space, such that, in this basis, the evolution is given by elements of the permutation group. This would restore an ontological interpretation. It is shown how, at low energies per particle degree of freedom, almost any quantum system allows for such a transformation. This contradicts Bell’s theorem, and we emphasise why some of the assumptions made by Bell to prove his theorem cannot hold for the models studied here. We speculate how an approach of this kind may become helpful in isolating the most likely version of the Standard Model, combined with General Relativity. A link is suggested with black hole physics.

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