Dynamical symmetrization of the state of identical particles

TL;DR

This paper introduces a dynamical model for the symmetrization of identical particle states, where a quantum jump during collision erases distinguishability, leading to symmetrized states, with potential experimental tests.

Contribution

It presents a novel dynamical approach to state symmetrization involving quantum jumps at collisions, linking measurement and symmetrization.

Findings

Quantum jumps induce state symmetrization during particle collisions

Symmetrization can be viewed as spontaneous measurement of collision time

Model provides experimentally testable predictions

Abstract

We propose a dynamical model for state symmetrization of two identical particles produced in spacelike-separated events by independent sources. We adopt the hypothesis that the pair of non-interacting particles can initially be described by a tensor product state since they are in principle distinguishable due to their spacelike separation. As the particles approach each other, a quantum jump takes place upon particle collision, which erases their distinguishability and projects the two-particle state onto an appropriately (anti)symmetrized state. The probability density of the collision times can be estimated quasi-classically using the Wigner functions of the particles' wavepackets, or derived from fully quantum mechanical considerations using an appropriately adapted time-of-arrival operator. Moreover, the state symmetrization can be formally regarded as a consequence of the spontaneous measurement of the collision time. We show that symmetric measurements performed on identical particles can in principle discriminate between the product and symmetrized states. Our model and its conclusions can be tested experimentally.