Three-Body Correlations In $^{6}$He Revealed In The Quasi-Free Knockout Reaction $^{4}He($^{6}$He,2$\alpha$)2n
Résumé
The 4He(6He,2$\alpha$)2n reaction was studied in experiments designed for the observation of a quasi-free scattering (QFS) occurring between the $\alpha$ core of the Borromean 6He nuclei and the 4He target nuclei. The helium gas target cooled down to 14 K was bombarded by a 25A MeV secondary beam of 6He nuclei produced at the fragment separator ACCULINNA (Dubna). The data were analyzed with the use of the Plane Wave Impulse Approximation (PWIA) and the three-body wave function of 6He and taking into account the n − n final state interaction. Correlation obtained in the reaction exit channel between the momentum values characteristic to the $\alpha$-2n and n-n subsystems were found to be consistent with the PWIA predictions. This suggests that QFS could be suitable for the study of other Borromean nuclei.