Extend Bethe–Heitler entanglement analysis to higher energies and spin-2 nuclei

Extend the analysis of three-qubit entanglement in the Bethe–Heitler process to higher center-of-mass energies, where deeply virtual Compton scattering corrections and the proton’s generalized parton distributions may affect the entanglement pattern, and to spin-2 nuclei such as helium-3.

Background

The paper studies tripartite entanglement among the final-state electron, proton, and photon in the Bethe–Heitler process using helicity amplitudes and numerical searches for states locally equivalent to GHZ and W states. The analysis is primarily focused on center-of-mass energies below 5 GeV and on a proton target.

The authors note that at higher center-of-mass energies, photon emission from the hard proton–virtual-photon interaction introduces deeply virtual Compton scattering corrections, potentially making the entanglement structure sensitive to generalized parton distributions. They also identify extending the analysis from protons to spin-2 nuclei, including helium-3, as a future unresolved direction.

References

At higher CM energies, corrections due to DVCS (photon emission from the hard p + γ∗ interaction) [6, 7] will become important. The pattern of entanglement may become sensitive to the partonic structure of the proton encoded in the GPDs. It is also interesting to extend the present analysis to spin-2 nuclei such as 3He [22, 57]. We leave these problems to future work.

— Three-qubit entanglement in the Bethe-Heitler process  (2608.18030 - Cao et al., 18 Aug 2026) in Conclusions, p. 5