Decay of entangled fermion pairs with post-selection
Author:
J. A. Aguilar-Saavedra
Keyword:
High Energy Physics - Phenomenology, High Energy Physics - Phenomenology (hep-ph), Quantum Physics (quant-ph)
journal:
IFT-UAM/CSIC-23-106
date:
2023-08-13 16:00:00
Abstract
We consider a pair of unstable fermions in a spin-entangled state. A spin measurement on one fermion, with a Stern-Gerlach experiment or similar, determines the spin state of its partner - even if it already has decayed. This post-selection effect would be experimentally accessible using muon pairs in a maximally-entangled state, produced either in the decay of a scalar particle, or in $e^+ e^-$ collisions at wide angles.