Interaction of evanescent particles with an Unruh-DeWitt detector

TL;DR

This paper shows that evanescent particles in a massive scalar field can be emitted and absorbed by an Unruh-DeWitt detector, carrying quantized energy similar to propagating particles but with less energy than the particle mass.

Contribution

It introduces methods to analyze the interaction of evanescent particles with Unruh-DeWitt detectors, expanding understanding of quantum field interactions beyond propagating particles.

Findings

Evanescent particles can be emitted and absorbed by the detector.

The energy carried by evanescent particles is positive but less than the particle mass.

The study provides emission and absorption spectra involving both propagating and evanescent particles.

Abstract

We demonstrate that the recently introduced evanescent particles of a massive scalar field can be emitted and absorbed by an Unruh-DeWitt detector. In doing so the particles carry away from or deposit on the detector a quantized amount of energy, in a manner quite analogous to ordinary propagating particles. In contradistinction to propagating particles the amount of energy is less than the mass of the field, but still positive. We develop relevant methods and provide a study of the detector emission spectrum, emission probability and absorption probability involving both propagating and evanescent particles.