Spin entanglement of two protons emitted from 6Be

We show that a two-proton emitter with a diproton-correlated initial state can act as a source of spin-correlated proton pairs. Using a time-dependent three-body model, we investigate the two-proton emission of $^{16}$ Ne ( $^{14}$ O $+2p$ ) and analyze the spin correlation of the emitted protons. We find that, when the emission proceeds as a democratic three-body process from an initial state containing a spin-singlet diproton correlation, the emitted protons exhibit a pronounced spin-correlation pattern exceeding the local-hidden-variable bound. This spin correlation closely resembles that of a pure spin-singlet pair. In contrast, this pattern is lost when the process is dominated by the sequential emission or when the initial diproton correlation is absent. These results demonstrate that a certain class of two-proton emitters can deliver spin-entangled proton pairs, and their spin correlation reflects the diproton correlation embedded in the initial state.We show that a two-proton emitter with a diproton-correlated initial state can act as a source of spin-correlated proton pairs. Using a time-dependent three-body model, we investigate the two-proton emission of $^{16}$Ne ($^{14}$O$+2p$) and analyze the spin correlation of the emitted protons. We find that, when the emission proceeds as a democratic three-body process from an initial state containing a spin-singlet diproton correlation, the emitted protons exhibit a pronounced spin-correlation pattern exceeding the local-hidden-variable bound. This spin correlation closely resembles that of a pure spin-singlet pair. In contrast, this pattern is lost when the process is dominated by the sequential emission or when the initial diproton correlation is absent. These results demonstrate that a certain class of two-proton emitters can deliver spin-entangled proton pairs, and their spin correlation reflects the diproton correlation embedded in the initial state.

nucl-thCross-listedarXiv:2512.15879Physics Letters BDec 19, 20250 citations

Spin correlation in two-proton emission from 6Be

Tomohiro Oishi

This paper presents a theoretical evaluation of spin correlation in the two-proton (2 p ) radioactive emission . The three-body model of 6 Be with the proton-proton interaction, which is adjusted to reproduce the experimental energy release, is utilized. Time-dependent calculations are performed to compute the coupled-spin state of the emitted two protons. The spin-correlation function S as the Clauser-Horne-Shimony-Holt (CHSH) indicator is evaluated as | S | ≅ 2.65 . Namely, the 2 p -spin correlation beyond the limit of local-hidden-variable (LHV) theory is suggested. This correlation is sensitive to the proton-proton interaction. The short-lived (broad-width) 2 p state has the weaker spin correlation. In parallel, the core-proton interactions do not harm this correlation during the time-dependent decaying process. The CHSH measurement can be a novel probe into the effective nuclear interaction inside finite systems. Two-proton emitters can provide a testing field for the identical-particle entanglement.This paper presents a theoretical evaluation of spin correlation in the two-proton (2 p ) radioactive emission . The three-body model of 6 Be with the proton-proton interaction, which is adjusted to reproduce the experimental energy release, is utilized. Time-dependent calculations are performed to compute the coupled-spin state of the emitted two protons. The spin-correlation function S as the Clauser-Horne-Shimony-Holt (CHSH) indicator is evaluated as | S | ≅ 2.65 . Namely, the 2 p -spin correlation beyond the limit of local-hidden-variable (LHV) theory is suggested. This correlation is sensitive to the proton-proton interaction. The short-lived (broad-width) 2 p state has the weaker spin correlation. In parallel, the core-proton interactions do not harm this correlation during the time-dependent decaying process. The CHSH measurement can be a novel probe into the effective nuclear interaction inside finite systems. Two-proton emitters can provide a testing field for the identical-particle entanglement.

arXiv:2407.11136Physics Letters BFeb 26, 20254 citations

Quantum Entanglement and Decoherence Due to Coupling of Protons to Electronic Environment

Tyno Abdul‐Redah, M. Krzystyniak, C. A. Chatzidimitriou‐Dreismann

Springer eBooksDec 13, 20051 citation

^{16}

Ne (

^{14}

+2p

) and analyze the spin correlation of the emitted protons. We find that, when the emission proceeds as a democratic three-body process from an initial state containing a spin-singlet diproton correlation, the emitted protons exhibit a pronounced spin-correlation pattern exceeding the local-hidden-variable bound. This spin correlation closely resembles that of a pure spin-singlet pair. In contrast, this pattern is lost when the process is dominated by the sequential emission or when the initial diproton correlation is absent. These results demonstrate that a certain class of two-proton emitters can deliver spin-entangled proton pairs, and their spin correlation reflects the diproton correlation embedded in the initial state.