https://doi.org/10.1140/epjd/s10053-023-00665-x
Comment – Quantum Optics
Comment on “Spin correlations in elastic e
e
scattering in QED”
1
Department of Physics, University of Illinois at Urbana-Champaign, 61801, Urbana, IL, USA
2
Facultad de Ciencias Físico-Matemáticas, Universidad Autónoma de Coahuila, 25000, Saltillo, Coahuila, Mexico
3
Department of Physics, University of Oregon, 97403, Eugene, OR, USA
4
Facultad de Ciencias, Universidad de Colima, 28045, Colima, Colima, Mexico
Received:
22
October
2022
Accepted:
25
January
2023
Published online:
28
May
2023
In the previous work, “Spin correlations in elastic 
scattering in QED” (Yongram in Eur Phys J 7:71–74, 2008), 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 the Clauser–Horne inequality (CHI) occurs at all energies for both mentioned cases, for fully polarized scattering we found violation of the CHI for speeds 
, 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. We argue that averaging over the initial polarizations washes out the non-local correlations needed to violate a Bell-type inequality.
© The Author(s), under exclusive licence to EDP Sciences, SIF and Springer-Verlag GmbH Germany, part of Springer Nature 2023
