Predictive status of QFT for detector-based tests of Newton–Wigner versus field localisation

Ascertain what relativistic quantum field theory predicts for experiments employing realistic local particle detectors intended to discriminate between Newton–Wigner localisation and localisation via local field algebras, by developing detector models whose approximations preserve the distinctions between the two localisation schemes and allow concrete, testable predictions.

Background

The paper reviews the tension between Newton–Wigner localisation (which exhibits superluminal propagation and microcausality issues) and localisation defined by local field algebras (which preserves microcausality). It highlights that empirical adjudication would require modeling realistic detectors made of particles, complicating the analysis.

The author argues that plausible detector models involve approximations that tend to erase the operational differences between the two localisation schemes, leaving it unclear what, if anything, the underlying field theory predicts about observable distinctions.