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Propagator (field theory)

The probability amplitude for a particle to move or propagate to some new point of space and time when its amplitude at some point of origination is known. The propagator occurs as an important part of the probability in reactions and interactions in all branches of modern physics. Its properties are best described in the framework of quantum field theory for relativistic particles, where it is written in terms of energy and momentum. Concrete examples for electron-proton and proton-proton scattering are provided in the illustration. The amplitude for these processes contains the propagators for the exchanged proton and meson, which actually specify the dominant part of the probability of each process when the scattering occurs at small angles. In similar fashion, for any electromagnetic process, a propagator for each internal line of the Feynman diagram (each line not connected directly to the outside world) enters the probability amplitude. See Feynman diagram, Quantum electrodynamics, Quantum field theory, Quantum mechanics

Feynman diagrams for scattering processesenlarge picture
Feynman diagrams for scattering processes
McGraw-Hill Concise Encyclopedia of Physics. © 2002 by The McGraw-Hill Companies, Inc.


(quantum mechanics)
The probability amplitude for a particle to move or propagate to some new point of space and time when its amplitude at some point of origination is known.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
From the perspective of the PV theory, the normalization of dt" by the Planck time [t.sub.*] and H by the Planck-particle mass energy [m.sub.*][c.sup.2] strongly suggest that the scattering in the quantum-electro-dynamic propagator theory is caused by the Planck-particle cores that pervade the vacuum state.
I haven't used a heated propagator, or heated a greenhouse other than to give minimal frost protection in extremis, for years.
There would be necessary books and propagators, with separate halls for males and females inside the Search and Follow-up Department for introducing Islam and spread its teachings among the detainees.
TOP BUYS: A spade, hosepipe spray gun, seed kit, propagator and expert book
Cheaper propagators tend to have one or two settings, such as cool and warm, irrespective of indoor temperatures, and have to be monitored carefully.
Courgettes, melons and sunflowers, for example, are traditionally sown late and can't be planted out in the garden until the end of May or beginning of June, so they won't benefit from being germinated in a heated propagator early because you'll still have to keep them indoors.
If you haven't got a greenhouse but want something bigger than a standard propagator a multi-grow is a self-assembly grow house which is available in various sizes to suit individual needs.
Upon calculating the radiative corrections with the fields, masses, and coupling constants renormalized within the OMS renormalization scheme, the UV divergencies occurring in the loop expansion (of propagators as well as S-matrix elements) are absorbed in the infinite parts of the renormalization constants.
The book focuses on its advocates and propagators. Quoting writings, and analyzing some of the most well known projects of such people--among them Johnson, Jencks, Gehry, Eisenman, Hadid, Libeskind and Tschumi, but also Derrida himself--Salingaros unveils the truth hidden underneath the meandering rhetoric of deconstruction.
Her "cruel and malevolent" enemies include not only the propagators of historical harms to her community but also art's silent complicity with those harms.
There are positives and negatives when it comes to propagators. They are convenient and you can set seeds off in your kitchen or greenhouse and have greater control over their germination.