Spin correlation in two-proton emission from 6Be

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.