High-Energy Decays and Weak Quantum Measurements

TL;DR

This paper demonstrates that high-energy particle decays naturally perform weak quantum measurements of spin, linking decay kinematics to quantum measurement theory and enabling new methods for probing quantum coherence in collider experiments.

Contribution

It introduces a framework connecting high-energy decay processes with weak measurement theory, unifying spin tomography and correlation analysis in particle physics.

Findings

Decay kinematics encode partial spin information as weak measurements.

Ensemble averages produce weak values linking to quantum measurement theory.

Relativistic decays can probe quantum coherence and interference phenomena.

Abstract

High-energy particle decays naturally realise informationally weak measurements of quantum spin. Decay kinematics act as continuous pointer variables whose overlapping angular distributions encode partial, non-projective information about the parent spin state. Ensemble averages of these pointers yield weak values, linking collider spin-density reconstruction to Aharonov-Vaidman measurement theory. This framework unifies spin tomography, entangled-decay correlations, and spin-correlation algorithms, showing that relativistic decays realise informationally weak measurements of spin and suggesting new ways to probe coherence and interference in high-energy processes.