Comment on "Spin correlations in elastic $e^+ e^-$ scattering in QED"

TL;DR

This paper revisits spin correlations in electron-positron scattering, correcting previous calculations and showing that CHI violation occurs only at high energies for fully polarized states, aligning with quantum mechanics principles.

Contribution

It provides corrected calculations of spin correlations in Bhabha scattering for polarized states at all energies, clarifying when CHI violation occurs.

Findings

CHI violation occurs at high energies for fully polarized states

No CHI violation for unpolarized initial states

Supports quantum mechanics consistency at high energies

Abstract

In the previous work, "Spin correlations in elastic $e^+ e^-$ scattering in QED" (Yongram, 2018), spin correlations for entangled electrons and positrons as emergent particles of electron-positron scattering (also known as Bhabha scattering) were calculated at tree level in QED. When trying to reproduce the author's work, we have found different results. In this work, we show the calculation for fully (initial and final polarized states) and partially (just final polarized states) polarized probability amplitudes for electron-positron scattering at all energies. While Yongram claims that violation of Clauser-Horne inequality (CHI) occurs at all energies for both mentioned cases, for fully polarized scattering we found violation of the CHI for speeds $\beta \gtrsim 0.696$, including the high energy limit, supporting the agreement between QED and foundations of quantum mechanics. However, for initially unpolarized particles we found no violation of the CHI.