Revisiting Zeno's paradox: Flying arrows for atom-diatom reactions

TL;DR

This paper investigates quantum Zeno and anti-Zeno effects in atom-diatom reactions using a novel wave packet approach that updates the initial state after measurements, avoiding paradoxical interpretations.

Contribution

It introduces a new method for observing quantum Zeno phenomena in reactive collisions without requiring hindered evolution assumptions.

Findings

Identifies regimes of inhibited and accelerated decay in atom-diatom reactions.

Proposes a wave packet approach that updates the initial state after measurements.

Avoids paradoxical interpretations by using a 'flying arrow' model.

Abstract

The possibility to observe quantum Zeno and anti-Zeno scenarios for atom-diatom reactive collisions is investigated for two diferent processes (F+HD and H+O_2) by means of time-dependent wave packet propagations. A novel approach is proposed in which the survival probabilities investigated are those obtained when the initial state is redefined after time intervals tau at which measurements are performed on the system. The comparison with the actual probability for the unperturbed system reveals the existence of a regime in which the decay from the initial state appears to be inhibited (the quantum Zeno effect) or accelerated (the anti-Zeno effect). In contrast with preceding interpretations, given that the time-evolving wave packet is not affected at any time ("flying arrow"), the present procedure does not require to invoke to counterintuitive hindered evolutions ("stopping arrow") to explain the results. On the contrary the consecutive update of the reference state of the system solves the apparent modern version of Zeno's paradox.