The physics of Hanbury Brown--Twiss intensity interferometry: from stars to nuclear collisions

TL;DR

This paper reviews the physics and diverse applications of Hanbury Brown--Twiss intensity interferometry, highlighting its role in measuring astronomical sources, quantum optics, and high energy nuclear collisions, as well as recent advances in condensed matter and atomic physics.

Contribution

It provides a comprehensive overview of the fundamental physics of intensity interferometry and its recent applications across multiple fields, emphasizing its ongoing relevance.

Findings

Intensity interferometry measures space-time geometry in nuclear collisions.

Quantum bunching of photons was demonstrated in incoherent light.

Applications now extend to condensed matter and atomic physics.

Abstract

In the 1950's Hanbury Brown and Twiss showed that one could measure the angular sizes of astronomical radio sources and stars from correlations of signal intensities, rather than amplitudes, in independent detectors. Their subsequent correlation experiments demonstrating quantum bunching of photons in incoherent light beams were seminal in the development of quantum optics. Since that time the technique of "intensity interferometry" has become a valuable probe of high energy nuclear and particle collisions, providing information on the space-time geometry of the collision. The effect is one of the few measurements in elementary particle detection that depends on the wave mechanics of the produced particles. Here we discuss the basic physics of intensity interferometry, and its current applications in high energy nuclear physics, as well as recent applications in condensed matter and atomic physics.