Anti-particle detector models in QFT

TL;DR

This paper introduces and analyzes new particle detector models in quantum field theory that couple linearly to fermionic and bosonic fields, capturing key features of particle and anti-particle detection.

Contribution

It proposes a simple linear complex scalar detector model that reflects fermionic detector features and explains the physical basis for using linear models over quadratic ones.

Findings

Linear complex scalar detector models effectively mimic fermionic detector behavior

The models respond distinctly to particle and anti-particle excitations

A mechanism is provided to restore U(1) symmetry in linear models

Abstract

We analyze families of particle detector models that linearly couple to different kinds of fermionic and bosonic fields. We also study the response of these detectors to particle and anti-particle excitations of the field. We propose a simple linear complex scalar particle detector model that captures the fundamental features of fermionic field detectors similarly to how the Unruh-DeWitt model captures the features of the light matter interaction. We also discuss why we do not need to limit ourselves to quadratic models commonly employed in past literature. Namely, we provide a physically motivated mechanism that restores U(1) symmetry in these linear complex models.