The Case of the Disappearing (and Re-Appearing) Particle

TL;DR

This paper uses the Two-State-Vector-Formalism to predict and experimentally verify a particle's nonlocal behavior in a three-box superposition, revealing its disappearance and reappearance at different locations through actual projective measurements.

Contribution

It introduces a novel prediction of particle behavior in a three-box superposition using TSVF with actual projective measurements, supported by weak measurements and the Aharonov-Bohm effect.

Findings

Particle disappears from one box and reappears in another without tunneling.

Local measurements fail to detect the particle, but combined measurements reveal nonlocal properties.

Results support a nonlocal, time-symmetric quantum ontology.

Abstract

A novel prediction is derived by the Two-State-Vector-Formalism (TSVF) for a particle superposed over three boxes. Under appropriate pre- and postselections, and with tunneling enabled between two of the boxes, it is possible to derive not only one, but three predictions for three different times within the intermediate interval. These predictions are moreover contradictory. The particle (when looked for using a projective measurement) seems to disappear from the first box where it would have been previously found with certainty, appearing instead within the third box, to which no tunneling is possible, and later re-appearing within the second. It turns out that local measurement (i.e. opening one of the boxes) fails to indicate the particle's presence, but subtler measurements performed on the two boxes together reveal the particle's nonlocal modular momentum spatially separated from its mass. Another advance of this setting is that, unlike other predictions of the TSVF that rely on weak and/or counterfactual measurements, the present one uses actual projective measurements. This outcome is then corroborated by adding weak measurements and the Aharonov-Bohm effect. The results strengthen the recently suggested time-symmetric Heisenberg ontology based on nonlocal deterministic operators. They can be also tested using the newly developed quantum router.