The appearance of particle tracks in detectors

TL;DR

This paper rigorously analyzes how quantum particles produce classical-like tracks in detectors, using a simplified model of repeated indirect measurements via laser pulses, under quadratic Hamiltonian assumptions.

Contribution

It introduces a mathematically rigorous model of particle track formation through repeated indirect measurements in a quantum setting.

Findings

Particle tracks emerge close to classical trajectories.

The analysis applies to quadratic Hamiltonian systems like free particles or harmonic oscillators.

The model clarifies the quantum-to-classical transition in detection scenarios.

Abstract

The phenomenon that a quantum particle propagating in a detector, such as a Wilson cloud chamber, leaves a track close to a classical trajectory is analyzed. We introduce an idealized quantum-mechanical model of a charged particle that is periodically illuminated by pulses of laser light resulting in repeated indirect measurements of the approximate position of the particle. For this model we present a mathematically rigorous analysis of the appearance of particle tracks, assuming that the Hamiltonian of the particle is quadratic in the position- and momentum operators, as for a freely moving particle or a harmonic oscillator.