El significado grupo teórico del espín

Abstract

El espín es una de las propiedades intrínsecas de las partículas elementales. Su definición a menudo viene dada cómo un momento angular intrínseco de valor fijo y en un principio se planteó como la rotación de la partícula, considerada esférica, alrededor de un eje propio. Esta descripción no es posible debido a que las partículas elementales son consideradas puntuales, y por tanto no es posible considerar su rotación sobre sí mismas.

Spin is an intrinsic property of particles, existent only in the context of quantum mechanics. It’s effects were first discovered in 1922 in an expertiment carried out by the scientists Otto Stern and Walther Gerlach, being firstly introduced as an angular momentum associated to the rotation of the electrons, until Wolfgang Pauli proposed a more abstract interpretation as a ”classically non describable two-valuedness”[10]. While the notion of the spin as an angular momentum associated to a spatial rotation has long been disproved, spin is still often refered as an intrisic angular momentum because of the similarities in their behavior. The objective of this thesis is to provide a faithful representation of the behaviour of spin and orbital angular momentum in relativistic and not relativistic situations, emphasizing the differences between them and indicating the inconsistencies that arise from considering the spin as an intrinsic angular momentum.