The physics of W ± and Z 0 particles

1986 ◽  
Vol 404 (1827) ◽  
pp. 189-211
Keyword(s):  
Standard Model ◽  
Weak Interaction ◽  
Theoretical Framework ◽  
Current Understanding ◽  
Electroweak Interactions ◽  
Decay Properties ◽  
The Standard Model

The standard model is a theoretical framework describing the behaviour of elementary quarks and leptons as a result of strong and electroweak interactions. Our current understanding of the production and decay properties of the W ± and Z 0 particles, the exchange bosons of the weak interaction, will be described and the striking agreement of these properties with predictions of the standard model will be emphasized.

scholarly journals WHAT IS A MATTER PARTICLE?

2006 ◽  
Vol 15 (01) ◽  
pp. 259-272
Author(s):  
TSAN UNG CHAN
Keyword(s):  
Standard Model ◽  
Weak Interaction ◽  
Strong Interaction ◽  
Neutral Particle ◽  
Z Bosons ◽  
Baryon Number ◽  
Lepton Number ◽  
Neutral Particles ◽  
The Standard Model ◽  
The Stability

Positive baryon numbers (A>0) and positive lepton numbers (L>0) characterize matter particles while negative baryon numbers and negative lepton numbers characterize antimatter particles. Matter particles and antimatter particles belong to two distinct classes of particles. Matter neutral particles are particles characterized by both zero baryon number and zero lepton number. This third class of particles includes mesons formed by a quark and an antiquark pair (a pair of matter particle and antimatter particle) and bosons which are messengers of known interactions (photons for electromagnetism, W and Z bosons for the weak interaction, gluons for the strong interaction). The antiparticle of a matter particle belongs to the class of antimatter particles, the antiparticle of an antimatter particle belongs to the class of matter particles. The antiparticle of a matter neutral particle belongs to the same class of matter neutral particles. A truly neutral particle is a particle identical with its antiparticle; it belongs necessarily to the class of matter neutral particles. All known interactions of the Standard Model conserve baryon number and lepton number; matter cannot be created or destroyed via a reaction governed by these interactions. Conservation of baryon and lepton number parallels conservation of atoms in chemistry; the number of atoms of a particular species in the reactants must equal the number of those atoms in the products. These laws of conservation valid for interaction involving matter particles are indeed valid for any particles (matter particles characterized by positive numbers, antimatter particles characterized by negative numbers, and matter neutral particles characterized by zero). Interactions within the framework of the Standard Model which conserve both matter and charge at the microscopic level cannot explain the observed asymmetry of our Universe. The strong interaction was introduced to explain the stability of nuclei: there must exist a powerful force to compensate the electromagnetic force which tends to cause protons to fly apart. The weak interaction with laws of conservation different from electromagnetism and the strong interaction was postulated to explain beta decay. Our observed material and neutral universe would signify the existence of another interaction that did conserve charge but did not conserve matter.

Electroweak Interactions and W, Z Boson Properties

2020 ◽  
Author(s):  
Maarten Boonekamp ◽  
Matthias Schott
Keyword(s):  
Standard Model ◽  
Weak Interaction ◽  
Top Quark ◽  
Quantum Electrodynamics ◽  
Weak Interactions ◽  
Higgs Field ◽  
Nuclear Research ◽  
Strong Interactions ◽  
Weak Boson ◽  
The Standard Model

With the huge success of quantum electrodynamics (QED) to describe electromagnetic interactions in nature, several attempts have been made to extend the concept of gauge theories to the other known fundamental interactions. It was realized in the late 1960s that electromagnetic and weak interactions can be described by a single unified gauge theory. In addition to the photon, the single mediator of the electromagnetic interaction, this theory predicted new, heavy particles responsible for the weak interaction, namely the W and the Z bosons. A scalar field, the Higgs field, was introduced to generate their mass. The discovery of the mediators of the weak interaction in 1983, at the European Center for Nuclear Research (CERN), marked a breakthrough in fundamental physics and opened the door to more precise tests of the Standard Model. Subsequent measurements of the weak boson properties allowed the mass of the top quark and of the Higgs Boson to be predicted before their discovery. Nowadays, these measurements are used to further probe the consistency of the Standard Model, and to place constrains on theories attempting to answer still open questions in physics, such as the presence of dark matter in the universe or unification of the electroweak and strong interactions with gravity.

scholarly journals Differences Between Two Weak Interaction Theories

2019 ◽  
pp. 1-9
Author(s):  
E. Comay
Keyword(s):  
Standard Model ◽  
Weak Interaction ◽  
Electroweak Theory ◽  
Interaction Theory ◽  
Quantum Theories ◽  
The Standard Model

This paper analyzes differences between theoretical elements of the Standard Model electroweak theory and corresponding properties of a dipole-dipole weak interaction theory. The analysis relies on a number of self-evident criteria that are valid for quantum theories. The results demonstrate the  existence of fundamental errors in the electroweak theory and the advantage of the dipole-dipole weak interaction theory.

scholarly journals DARK MATTER CANDIDATE FROM CONFORMALITY

2007 ◽  
Vol 22 (13) ◽  
pp. 931-937 ◽  
Author(s):  
P. H. FRAMPTON
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Cross Section ◽  
Weak Interaction ◽  
Gauge Theories ◽  
Dark Matter Candidate ◽  
Beyond The Standard Model ◽  
The Standard Model ◽  
Relic Density ◽  
Baryonic Dark Matter

Abelian quiver gauge theories provide candidates for the conformality approach to physics beyond the standard model which possess novel cancellation mechanisms for quadratic divergences. A Z2 symmetry ( R parity) can be imposed and leads naturally to a dark matter candidate which is the Lightest Conformality Particle (LCP), a neutral spin-1 / 2 state with weak interaction annihilation cross-section, mass in the 100 GeV region and relic density of non-baryonic dark matter Ωdm which can be consistent with the observed value Ωdm≃0.24.

A DETAILED ACCOUNT OF ALAIN CONNES' VERSION OF THE STANDARD MODEL IN NON-COMMUTATIVE GEOMETRY: I AND II.

1993 ◽  
Vol 05 (03) ◽  
pp. 477-532 ◽  
Author(s):  
DANIEL KASTLER
Keyword(s):  
Standard Model ◽  
Coupling Constants ◽  
Fermion Mass ◽  
Detailed Calculation ◽  
Coupling Constant ◽  
Electroweak Interactions ◽  
Symmetrical Form ◽  
Mass Matrices ◽  
The Standard Model ◽  
Universal Coupling

We present a detailed calculation of the Lagrangian of the standard model prescribed in the paper [4] of Connes and Lott, first for the electroweak interactions alone, and then (as is necessary to achieve the correct weak hypercharge assignments) for the coupling of electroweak interactions with chromodynamics. In its most symmetrical form (with free parameters the fermion mass-matrices plus one universal coupling constant), the Connes theory in tree-approximation yields equality of the strong and electroweak coupling constants, and fixes the value sin 2 θw = 3/8, and the ratios mt/mw and mH/mt.

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