New insight into knockout reactions from the two-proton halo nucleus Ne17

Abstract

The unexplained disagreement in the dependence of spectroscopic factors (C2Sexp) on the binding energy obtained by nucleon knockout using different targets is still a puzzle that needs to be addressed. To find an explanation of this riddle through exclusive measurements using different targets. The exclusive measurements were performed by using a Ne17 beam with an energy of 500 MeV/u incident on C and CH2 targets. Through the standard theoretical approach, C2Sexp were derived from the analysis of the experimental data on proton ejection from the proton halo in Ne17 as well as from its core O15. For the C target, proton ejection from the proton halo gave C2Sexp about 37% smaller than for the H target. But when protons are ejected from the core of Ne17, C2Sexp are identical within statistical uncertainties. An explanation for the difference in C2Sexp could be the removal of both halo protons, a more important reaction pathway for the C target. The C2Sexp values obtained by analyzing the proton ejection from the core indicate that it is not affected by the interaction with the halo protons.Published by the American Physical Society2024