Heavy leptons and unified theories of weak and electromagnetic interactions

1974 ◽  
Vol 10 (11) ◽  
pp. 441-447 ◽  
Author(s):  
W. Alles
Keyword(s):  
Electromagnetic Interactions ◽  
Unified Theories ◽  
Heavy Leptons

Vortices in unified theories of weak and electromagnetic interactions

1980 ◽  
Vol 90 (1-2) ◽  
pp. 135-137 ◽  
Author(s):  
A.S. Schwarz ◽  
Yu.S. Tyupkin
Keyword(s):  
Electromagnetic Interactions ◽  
Unified Theories

scholarly journals TOPOLOGICAL DEFECTS AND STRUCTURE FORMATION

1994 ◽  
Vol 09 (13) ◽  
pp. 2117-2189 ◽  
Author(s):  
ROBERT H. BRANDENBERGER
Keyword(s):  
Phase Transitions ◽  
Structure Formation ◽  
Early Universe ◽  
Topological Defects ◽  
Electromagnetic Interactions ◽  
Unified Theories

Topological defects are produced during phase transitions in the very early Universe. They arise in most unified theories of strong, weak and electromagnetic interactions. This article focuses on the role of topological defects in cosmology, with particular emphasis on the models of structure formation based on defects. The role of topological defects in baryogenesis is also reviewed.

Heavy leptons

1977 ◽  
Vol 355 (1683) ◽  
pp. 585-599 ◽  
Keyword(s):  
Electromagnetic Coupling ◽  
Axial Vector ◽  
Weak Current ◽  
Electromagnetic Interactions ◽  
Heavy Leptons ◽  
Charged Leptons ◽  
Neutral Heavy Leptons ◽  
Coupling Point ◽  
Definition Of ◽  
Exciting Possibility

The exciting possibility that a new lepton may exist (Perl et al . 1975; Richter 1977) raises many immediate questions such as : is its electromagnetic coupling point-like (which is perhaps the definition of a lepton)? Does it have its own conserved lepton number or does it have L e = ± 1 or L μ = ± 1? In the former case, what is the mass of the corresponding neutrino? If it has non-zero electron or muon number, are there also heavy neutral states E 0 or M 0 ? How does it decay ? With strength G F ? Does it couple to the usual weak current ( W ) or to some new current ( W' )? Is the coupling a vector-axial vector mixture, and if so in what proportion, or are there S, P or T couplings? To sharpen these questions and illustrate the available possibilities it is useful to begin by recalling theoretical arguments for the introduction of heavy leptons and some schemes which incorporate them. Next we discuss how hypothetical charged leptons might decay and how they might be produced, following which we briefly consider neutral heavy leptons. Finally we discuss the possibility of ‘hadro-leptons’ which enjoy more than just weak and electromagnetic interactions. A vast amount of work has been done on heavy leptons over the years and the discovery of events in which e + e¯→eμ +neutrals in the SLAC-LBL experiment at SPEAR last year has led to many new investigations. This report, which is based on a half-hour talk, does not pretend to be a complete review but much of the literature may be traced from the references.

Particles, antiparticles, and generalized anomalies in grand unified theories

1983 ◽  
Vol 61 (8) ◽  
pp. 1169-1171
Author(s):  
Mark Singer
Keyword(s):  
Large Class ◽  
Charged Particles ◽  
Electromagnetic Interactions ◽  
Grand Unified Theories ◽  
Unified Theories

Grand unified theories of strong–weak electromagnetic interactions require both chiral states of all charged fermions to be present so that the theories will have no massless charged particles. For a large class of theories this condition requires not only the absence of all triangle anomalies, but the absence of "odd-number generalized anomalies" as well. Conversely, the requirement that these theories be odd-number generalized anomaly free guarantees that both chiral states of all charged fermions arc present, and thus all charged fermions can acquire mass.

The Standard Theory

2017 ◽  
Author(s):  
John Iliopoulos
Keyword(s):  
Gauge Theory ◽  
Invariant Theory ◽  
Standard Theory ◽  
Strong Interactions ◽  
Gauge Invariant ◽  
Electromagnetic Interactions ◽  
Protons And Neutrons ◽  
Free Particles ◽  
Theoretical Predictions ◽  
Theory And Experiment

All ingredients of the previous chapters are combined in order to build a gauge invariant theory of the interactions among the elementary particles. We start with a unified model of the weak and the electromagnetic interactions. The gauge symmetry is spontaneously broken through the BEH mechanism and we identify the resulting BEH boson. Then we describe the theory known as quantum chromodynamics (QCD), a gauge theory of the strong interactions. We present the property of confinement which explains why the quarks and the gluons cannot be extracted out of the protons and neutrons to form free particles. The last section contains a comparison of the theoretical predictions based on this theory with the experimental results. The agreement between theory and experiment is spectacular.

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 Soft photon theorem in the small negative cosmological constant limit

2021 ◽  
Vol 2021 (8) ◽  
Author(s):  
Nabamita Banerjee ◽  
Karan Fernandes ◽  
Arpita Mitra
Keyword(s):  
Cosmological Constant ◽  
Tree Level ◽  
Leading Order ◽  
Asymptotically Flat ◽  
Soft Factor ◽  
Flat Spacetime ◽  
Electromagnetic Interactions ◽  
Flat Spacetimes ◽  
Perturbative Corrections ◽  
Soft Factors

Abstract We study the effect of electromagnetic interactions on the classical soft theorems on an asymptotically AdS background in 4 spacetime dimensions, in the limit of a small cosmological constant or equivalently a large AdS radius l. This identifies 1/l2 perturbative corrections to the known asymptotically flat spacetime leading and subleading soft factors. Our analysis is only valid to leading order in 1/l2. The leading soft factor can be expected to be universal and holds beyond tree level. This allows us to derive a 1/l2 corrected Ward identity, following the known equivalence between large gauge Ward identities and soft theorems in asymptotically flat spacetimes.

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