Quantum state of a free spin-1/2 particle and the inextricable dependence of spin and momentum under Lorentz transformations

TL;DR

This paper revisits the Dirac equation for free particles, examining how Lorentz transformations affect spinors and revealing the fundamental link between spin and momentum in relativistic quantum mechanics.

Contribution

It provides a detailed analysis of the Lorentz transformation effects on spinors and clarifies the inseparable relationship between spin and momentum.

Findings

Lorentz transformations alter the spin quantization axis.

Spin and momentum are fundamentally interconnected under Lorentz transformations.

The study offers insights into relativistic spin dynamics.

Abstract

We revise the Dirac equation for a free particle and investigate Lorentz transformations on spinors. We study how the spin quantization axis changes under Lorentz transformations, and evince the interplay between spin and momentum in this context.