Weak intermediate bosons and unitary symmetry

1965 ◽  
Vol 288 (1413) ◽  
pp. 166-169
Keyword(s):  
Experimental Evidence ◽  
Weak Interactions ◽  
Coupling Constants ◽  
Unitary Symmetry ◽  
Intermediate Bosons ◽  
The Subject ◽  
Difficult Subject

The subject I am supposed to report on is intermediate bosons and unitary symmetry. This is a difficult subject for two reasons. The first is that there is at the present time no experimental evidence at all that these bosons really exist. The second one is that, even if they exist, we do not know whether they have really something to do with unitary symmetry. These are serious objections, especially the first. The reason why, in spite of it, I still want to give this talk is the following. Most theoretical physicists believe, I think, that we cannot live for ever with the weak interactions just being described by effective Fermi coupling constants and the like.

scholarly journals Symmetry breakdown and coupling constants of leptons

2007 ◽  
Vol 79 (2) ◽  
pp. 195-208 ◽  
Author(s):  
Gil C. Marques ◽  
Dominique Spehler
Keyword(s):  
Coupling Constants ◽  
Electroweak Interactions ◽  
New Approach ◽  
Fundamental Interactions ◽  
Electromagnetic Interactions ◽  
Symmetry Breakdown ◽  
A Value ◽  
Intermediate Bosons ◽  
The One ◽  
The Way

Based on a new approach to symmetries of the fundamental interactions we deal, in this paper, with the electroweak interactions of leptons. We show that the coupling constants, arising in the way leptons are coupled to intermediate bosons, can be understood as parameters associated to the breakdown of SU(2) and parity symmetries. The breakdown of both symmetries is characterized by a new parameter (the asymetry parameter) of the electroweak interactions. This parameter gives a measure of the strength of breakdown of symmetries. We analyse the behaviour of the theory for three values of this parameter. The most relevant value is the one for which only the electromagnetic interactions do not break parity (the maximally allowed left-right asymetric theory). Maximamally allowed parity asymmetry is a requirement that is met for a value of Weinberg's theta-angle that is quite close to the experimental value of this parameter.

A comparison of electron spin resonance α- and β-hyperfine coupling constants in para-substituted α-phenethyl radicals

1986 ◽  
Vol 64 (4) ◽  
pp. 769-772 ◽  
Author(s):  
Donald R. Arnold ◽  
A. Martin de P. Nicholas ◽  
Kent M. Young
Keyword(s):  
Electron Spin Resonance ◽  
Experimental Evidence ◽  
Linear Relationship ◽  
Electron Spin ◽  
Hyperfine Coupling ◽  
Coupling Constants ◽  
Hyperfine Coupling Constants ◽  
Spin Resonance ◽  
Benzyl Radicals ◽  
Spin Delocalization

The linear relationship between the electron spin resonance hyperfine coupling constants (hfc) of the α- and β-hydrogens of para-substituted α-phenethyl radicals provides experimental evidence that the magnitude of both the α- and β -hfc is determined largely by the extent of spin delocalization in these benzylic systems. The [Formula: see text] scale, developed using substituted benzyl radicals, is shown to apply to phenethyl radicals as well.

scholarly journals VIII. The influence of Molecular constitution and temperature on magnetic susceptibility. Part IV. - Further applications of the molecular field

1920 ◽  
Vol 220 (571-581) ◽  
pp. 247-289 ◽  
Keyword(s):  
Magnetic Susceptibility ◽  
Experimental Evidence ◽  
Royal Society ◽  
Molecular Theory ◽  
Molecular Field ◽  
Molecular Configuration ◽  
Material Medium ◽  
The Subject ◽  
Molecular Constitution ◽  
Crystalline Symmetry

The present work is a continuation of that published in ‘Phil. Trans., Royal Society,’ vol. 214, pp. 109-146, 1914 (Parts I. and II.) and vol. 215, pp. 79-103, 1915 (Part III.). It will lead to clearness in the following development of the subject if a brief résumé of these papers is given. A t the same time, I wish to discuss one or two points in connexion with the views which have been previously advanced and the relation between mechanical and molecular theory. In Part I. the experimental evidence brought forward has justified the hypothesis of molecular distortion enunciated at the outset. We have thereby been led to regard the molecular configuration of a material medium as a distorted one, and this applies particularly to a substance which is crystalline. The extent of this distortion is small, but is sufficient to account for the observed change of specific susceptibility which occurs on crystallization. Such change will naturally depend upon the particular crystalline symmetry assumed by the substance.

Experimental evidence that acorn woodpeckers recognize relationships among third parties no longer living together

2020 ◽  
Vol 31 (5) ◽  
pp. 1257-1265 ◽  
Author(s):  
Michael A Pardo ◽  
Eric L Walters ◽  
Walter D Koenig
Keyword(s):  
Experimental Evidence ◽  
Social Group ◽  
Third Parties ◽  
Social Species ◽  
Living Together ◽  
Melanerpes Formicivorus ◽  
Group Members ◽  
The Subject ◽  
Acorn Woodpeckers ◽  
Group Relationships

Abstract Triadic awareness, or knowledge of the relationships between others, is essential to navigating many complex social interactions. While some animals maintain relationships with former group members post-dispersal, recognizing cross-group relationships between others may be more cognitively challenging than simply recognizing relationships between members of a single group because there is typically much less opportunity to observe interactions between individuals that do not live together. We presented acorn woodpeckers (Melanerpes formicivorus), a highly social species, with playback stimuli consisting of a simulated chorus between two different individuals, a behavior that only occurs naturally between social affiliates. Subjects were expected to respond less rapidly if they perceived the callers as having an affiliative relationship. Females responded more rapidly to a pair of callers that never co-occurred in the same social group, and responded less rapidly to callers that were members of the same social group at the time of the experiment and to callers that last lived in the same group before the subject had hatched. This suggests that female acorn woodpeckers can infer the existence of relationships between conspecifics that live in separate groups by observing them interact after the conspecifics in question no longer live in the same group as each other. This study provides experimental evidence that nonhuman animals may recognize relationships between third parties that no longer live together and emphasizes the potential importance of social knowledge about distant social affiliates.

scholarly journals Further Observations on the Fungicidal Action of Bordeaux Mixtures

1914 ◽  
Vol 6 (2) ◽  
pp. 220-232
Author(s):  
B. T. P. Barker ◽  
C. T. Gimingam
Keyword(s):  
Carbon Dioxide ◽  
Experimental Evidence ◽  
Copper Sulphate ◽  
Copper Compound ◽  
Fungicidal Action ◽  
The Subject ◽  
Solvent Action

In earlier papers (this Journal, vol. IV. pp. 69 and 76) we have detailed the experimental evidence which led us to conclude (1) that the view as to the fungicidal action of Bordeaux mixtures favoured by Pickering, viz. the liberation of copper sulphate by atmospheric carbon dioxide, is untenable; and (2) that contact between the fungus and the copper compound present in the mixture will account largely for its efficiency owing to a solvent action on the part of the organism under certain conditions. Pickering (this Journal, V. p. 273) has criticised our general conclusions and the deductions which we have drawn from certain of our experiments; and therefore before describing our further work on the subject, a brief reference to some of the points which he has raised is desirable.

Intermediate bosons and unitary symmetry

1964 ◽  
Vol 33 (3) ◽  
pp. 948-964 ◽  
Author(s):  
B. D’Espagnat ◽  
Y. Villachon
Keyword(s):  
Unitary Symmetry ◽  
Intermediate Bosons
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