https://doi.org/10.1140/epjc/s10052-026-15694-0
Letter
High-energy decays and weak quantum measurements
1
Department of Physics, University of Oxford, Keble Road, OX1 3RH, Oxford, UK
2
Merton College, Merton Street, OX1 4JD, Oxford, UK
3
Departement de Physique Nucleaire et Corpusculaire, Universite de Geneve, Quai Ernest-Ansermet 24, CH-1211, Geneve, Switzerland
a
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Received:
24
November
2025
Accepted:
11
April
2026
Published online:
25
April
2026
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.
© The Author(s) 2026
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