A reconstruction of quantum theory for spinning particles

Fuente: arXiv
Saved in:
Bibliographic Details
Main Author: Klein, Ulf
Format: Preprint
Published: 2022
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866916614765543424
author Klein, Ulf
author_facet Klein, Ulf
contents As part of a probabilistic reconstruction of quantum theory (QT), we show that spin is not a purely quantum mechanical phenomenon, as has long been assumed. Rather, this phenomenon occurs before the transition to QT takes place, namely in the area of the quasi-classical (here better quasi-quantum) theory. This borderland between classical physics and QT can be reached within the framework of our reconstruction by the replacement $p \rightarrow M (q, t)$, where $p$ is the momentum variable of the particle and $M(q, t)$ is the momentum field in configuration space. The occurrence of spin, and its special value $1/2$ , is a consequence of the fact that $M(q,t)$ must have exactly three independent components $M_{k}(q,t)$ for a single particle because of the three-dimensionality of space. In the Schrödinger equation for a "particle with spin zero", the momentum field is usually represented as a gradient of a single function $S$. This implies dependencies between the components $M_{k}(q,t)$ for which no explanation exists. In reality, $M(q,t)$ needs to be represented by three functions, two of which are rotational degrees of freedom. The latter are responsible for the existence of spin. All massive structureless particles in nature must therefore be spin-one-half particles, simply because they have to be described by $4$ real fields, one of which has the physical meaning of a probability density, while the other three are required to represent the momentum field in three-dimensional space. We derive the Pauli-Schrödinger equation, the correct value $g=2$ of the gyromagnetic ratio, the classical limit of the Pauli-Schrödinger equation, and clarify some other open questions in the borderland between classical physics and QT.
format Preprint
id arxiv_https___arxiv_org_abs_2202_13364
institution arXiv
publishDate 2022
record_format arxiv
spellingShingle A reconstruction of quantum theory for spinning particles
Klein, Ulf
Quantum Physics
High Energy Physics - Theory
81P05, 81S99, 60A99, 70H99
As part of a probabilistic reconstruction of quantum theory (QT), we show that spin is not a purely quantum mechanical phenomenon, as has long been assumed. Rather, this phenomenon occurs before the transition to QT takes place, namely in the area of the quasi-classical (here better quasi-quantum) theory. This borderland between classical physics and QT can be reached within the framework of our reconstruction by the replacement $p \rightarrow M (q, t)$, where $p$ is the momentum variable of the particle and $M(q, t)$ is the momentum field in configuration space. The occurrence of spin, and its special value $1/2$ , is a consequence of the fact that $M(q,t)$ must have exactly three independent components $M_{k}(q,t)$ for a single particle because of the three-dimensionality of space. In the Schrödinger equation for a "particle with spin zero", the momentum field is usually represented as a gradient of a single function $S$. This implies dependencies between the components $M_{k}(q,t)$ for which no explanation exists. In reality, $M(q,t)$ needs to be represented by three functions, two of which are rotational degrees of freedom. The latter are responsible for the existence of spin. All massive structureless particles in nature must therefore be spin-one-half particles, simply because they have to be described by $4$ real fields, one of which has the physical meaning of a probability density, while the other three are required to represent the momentum field in three-dimensional space. We derive the Pauli-Schrödinger equation, the correct value $g=2$ of the gyromagnetic ratio, the classical limit of the Pauli-Schrödinger equation, and clarify some other open questions in the borderland between classical physics and QT.
title A reconstruction of quantum theory for spinning particles
topic Quantum Physics
High Energy Physics - Theory
81P05, 81S99, 60A99, 70H99
url https://arxiv.org/abs/2202.13364