Revista: | Revista mexicana de física |
Base de datos: | PERIÓDICA |
Número de sistema: | 000425944 |
ISSN: | 0035-001X |
Autores: | Shikakhwa, M.S1 Albaid, A1 |
Instituciones: | 1University of Jordan, Ammán. Jordania |
Año: | 2017 |
Periodo: | Sep-Oct |
Volumen: | 63 |
Número: | 5 |
País: | México |
Idioma: | Inglés |
Tipo de documento: | Artículo |
Enfoque: | Analítico, teórico |
Resumen en inglés | We investigate the spin dynamics and the conservation of helicity in the first order S-matrix of a Dirac particle in any static magnetic field. We express the dynamical quantities using a coordinate system defined by the three mutually orthogonal vectors; the total momentum k = p f + p i, the momentum transfer q = p f - p i, and l = k × q. We show that this leads to an alternative symmetric description of the conservation of helicity in a static magnetic field at first order. In particular, we show that helicity conservation in the transition can be viewed as the invariance of the component of the spin along k and the flipping of its component along q, just as what happens to the momentum vector of a ball bouncing off a wall. We also derive a “plug and play" formula for the transition matrix element where the only reference to the specific field configuration, and the incident and outgoing momenta is through the kinematical factors multiplying a general matrix element that is independent of the specific vector potential present |
Disciplinas: | Física y astronomía |
Palabras clave: | Matriz S, Dispersión, Ecuación de Dirac, Conservación de la helicidad |
Keyword: | Physics, S-matrix, Scattering, Dirac equation, Helicity conservation |
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