Dynamical supersymmetry breaking and asymptotic freedom in non-Abelian gauge theories

Chapter 13 is devoted to some aspects of quantum chromodynamics (QCD), the part of the Standard Model of particle physics responsible for strong interactions and based on an SU(3) gauge symmetry (the colour group) and gluon gauge fields. First, the geometry of non–Abelian gauge theories, based on parallel transport, is recalled. This leads naturally to the construction of lattice gauge theories with link variables and a plaquette action. The lattice model gives a hint of confinement. QCD is quantized in the temporal of Weyl gauge. Its renormalization involves the BRST symmetry. Its renormalization group properties with asymptotic freedom are emphasized. The infinite degeneracy of the semi–classical ground state can be associated to a winding number. Barrier penetration effects, related to the existence of instantons, lead to the existence of theta vacua and the problem of strong CP violation. Other issues considered are chiral symmetry and axial anomaly.

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Quantum spectra of zero modes, topological vacua and dynamical supersymmetry breaking in non‐abelian gauge theories

Journal of Mathematical Physics ◽

10.1063/1.529609 ◽

1992 ◽

Vol 33 (7) ◽

pp. 2409-2416

Author(s):

H. Zhang

Keyword(s):

Supersymmetry Breaking ◽

Gauge Theories ◽

Abelian Gauge ◽

Zero Modes ◽

Quantum Spectra

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Geometry and Quantum Dynamics

10.1093/oso/9780198788393.003.0014 ◽

2017 ◽

Author(s):

Laurent Baulieu ◽

John Iliopoulos ◽

Roland Sénéor

Keyword(s):

General Relativity ◽

Quantum Dynamics ◽

Gauge Theories ◽

Brst Symmetry ◽

Abelian Gauge ◽

Yang Mills ◽

History Of ◽

Brst Invariance

A geometrical derivation of Abelian and non- Abelian gauge theories. The Faddeev–Popov quantisation. BRST invariance and ghost fields. General discussion of BRST symmetry. Application to Yang–Mills theories and general relativity. A brief history of gauge theories.

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Cwebs beyond three loops in multiparton amplitudes

Journal of High Energy Physics ◽

10.1007/jhep03(2021)188 ◽

2021 ◽

Vol 2021 (3) ◽

Author(s):

Neelima Agarwal ◽

Lorenzo Magnea ◽

Sourav Pal ◽

Anurag Tripathi

Keyword(s):

Gauge Theories ◽

Anomalous Dimension ◽

Wilson Line ◽

Building Blocks ◽

Feynman Diagrams ◽

Loop Order ◽

Abelian Gauge ◽

Sum Rule ◽

Combinatorial Properties ◽

Low Dimensional

Abstract Correlators of Wilson-line operators in non-abelian gauge theories are known to exponentiate, and their logarithms can be organised in terms of collections of Feynman diagrams called webs. In [1] we introduced the concept of Cweb, or correlator web, which is a set of skeleton diagrams built with connected gluon correlators, and we computed the mixing matrices for all Cwebs connecting four or five Wilson lines at four loops. Here we complete the evaluation of four-loop mixing matrices, presenting the results for all Cwebs connecting two and three Wilson lines. We observe that the conjuctured column sum rule is obeyed by all the mixing matrices that appear at four-loops. We also show how low-dimensional mixing matrices can be uniquely determined from their known combinatorial properties, and provide some all-order results for selected classes of mixing matrices. Our results complete the required colour building blocks for the calculation of the soft anomalous dimension matrix at four-loop order.

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Covariant phase space and soft factorization in non-Abelian gauge theories

Journal of High Energy Physics ◽

10.1007/jhep03(2021)015 ◽

2021 ◽

Vol 2021 (3) ◽

Author(s):

Temple He ◽

Prahar Mitra

Keyword(s):

Phase Space ◽

Ward Identity ◽

Gauge Theories ◽

Minkowski Spacetime ◽

Soft Gluon ◽

Careful Study ◽

Abelian Gauge ◽

Gauge Sector ◽

Vacuum States ◽

The One

Abstract We perform a careful study of the infrared sector of massless non-abelian gauge theories in four-dimensional Minkowski spacetime using the covariant phase space formalism, taking into account the boundary contributions arising from the gauge sector of the theory. Upon quantization, we show that the boundary contributions lead to an infinite degeneracy of the vacua. The Hilbert space of the vacuum sector is not only shown to be remarkably simple, but also universal. We derive a Ward identity that relates the n-point amplitude between two generic in- and out-vacuum states to the one computed in standard QFT. In addition, we demonstrate that the familiar single soft gluon theorem and multiple consecutive soft gluon theorem are consequences of the Ward identity.

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