Colliders are not testing locality via Bell’s inequality nor providing an unconditional proof of entanglement
- 1Durham University
- 2Bethe Center for Theoretical Physics & Physikalisches Institut der Universität Bonn
- 3Jožef Stefan Institute
Abstract
A bstract Recently there has been an increased interest in possible tests of locality via Bell’s inequalities, as well as separately tests of entanglement at colliders, in particular at the LHC. These have involved various physical processes, such as tt̅ t t ¯ , or τ + τ − production, or the decay of a Higgs boson to two vector bosons H → VV ∗ . We argue that none of these proposals constitute a test of locality via Bell’s inequality or promise unconditional observational evidence of entanglement. In all cases what is measured are the momenta of the final state particles. Using the construction proposed by Kasday (1971) in a different context, and adapted to collider scenarios by Abel, Dittmar, and Dreiner (1992), it is straightforward to construct a local hidden variable theory (LHVT) which exactly reproduces the data. This construction is only possible as the final state momenta all commute. We show that this LHVT satisfies Bell’s inequality or the related CHSH inequality as appropriate for all the proposed LHC collider tests in the literature. Thus a test of locality via Bell’s inequality is not possible at colliders. The LHVT is also by construction local, i.e. all correlations are separable. Thus an unconditional proof of entanglement is also inherently not possible at colliders. It can only be shown that the entanglement within the Standard Model consistently describes the data.
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BibTeX
@article{abel2026colliders,
title = {{Colliders are not testing locality via Bell’s inequality nor providing an unconditional proof of entanglement}},
author = {Steven Adam Abel and Herbi K. Dreiner and Rhitaja Sengupta and Lorenzo Ubaldi},
journal = {Journal of High Energy Physics},
year = {2026},
month = aug,
doi = {10.1007/jhep08(2026)067},
url = {https://doi.org/10.1007/jhep08(2026)067},
note = {CC BY},
}
RIS
TY - JOUR
TI - Colliders are not testing locality via Bell’s inequality nor providing an unconditional proof of entanglement
AU - Steven Adam Abel
AU - Herbi K. Dreiner
AU - Rhitaja Sengupta
AU - Lorenzo Ubaldi
PY - 2026
DA - 2026/08/07
JO - Journal of High Energy Physics
DO - 10.1007/jhep08(2026)067
UR - https://doi.org/10.1007/jhep08(2026)067
AB - A bstract Recently there has been an increased interest in possible tests of locality via Bell’s inequalities, as well as separately tests of entanglement at colliders, in particular at the LHC. These have involved various physical processes, such as tt̅ t t ¯ , or τ + τ − production, or the decay of a Higgs boson to two vector bosons H → VV ∗ . We argue that none of these proposals constitute a test of locality via Bell’s inequality or promise unconditional observational evidence of entanglement. In all cases what is measured are the momenta of the final state particles. Using the construction proposed by Kasday (1971) in a different context, and adapted to collider scenarios by Abel, Dittmar, and Dreiner (1992), it is straightforward to construct a local hidden variable theory (LHVT) which exactly reproduces the data. This construction is only possible as the final state momenta all commute. We show that this LHVT satisfies Bell’s inequality or the related CHSH inequality as appropriate for all the proposed LHC collider tests in the literature. Thus a test of locality via Bell’s inequality is not possible at colliders. The LHVT is also by construction local, i.e. all correlations are separable. Thus an unconditional proof of entanglement is also inherently not possible at colliders. It can only be shown that the entanglement within the Standard Model consistently describes the data.
SN - 1029-8479
SN - 1126-6708
SN - 1127-2236
ER -