Unveiling the two-proton halo character of <SUP>17</SUP>Ne: Exclusive measurement of quasi-free proton-knockout reactions

Lehr, C, Wamers, F, Aksouh, F, Aksyutina, Yu, Alvarez-Pol, H, Atar, L, Aumann, T, Beceiro-Novo, S, Bertulani, CA, Boretzky, K
et al (show 55 more authors) (2022) Unveiling the two-proton halo character of <SUP>17</SUP>Ne: Exclusive measurement of quasi-free proton-knockout reactions. PHYSICS LETTERS B, 827. p. 136957.

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The proton drip-line nucleus 17Ne is investigated experimentally in order to determine its two-proton halo character. A fully exclusive measurement of the 17Ne(p,2p)16F->15O+p quasi-free one-proton knockout reaction has been performed at GSI at around 500 MeV/nucleon beam energy. All particles resulting from the scattering process have been detected. The relevant reconstructed quantities are the angles of the two protons scattered in quasi-elastic kinematics, the decay of 16F into 15O (including gamma decays from excited states) and a proton, as well as the 15O+p relative-energy spectrum and the 16F momentum distributions. The latter two quantities allow an independent and consistent determination of the ratio of l=0 and l=2 motion of the valence protons in 17Ne. With a resulting relatively small l=0 component of only around 35(3)%, it is concluded that 17Ne exhibits a rather modest halo character only. The quantitative agreement of the two values deduced from the energy spectrum and the momentum distributions supports the theoretical treatment of the calculation of momentum distributions after quasi-free knockout reactions at high energies by taking into account distortions based on the Glauber theory. Moreover, the experimental data allow the separation of valence-proton knockout and knockout from the 15O core. The latter process contributes with 11.8(3.1) mb around 40% to the total proton-knockout cross section of 30.3(2.3) mb, which explains previously reported contradicting conclusions derived from inclusive cross sections.

Item Type: Article
Additional Information: 7 pages, 5 figures
Uncontrolled Keywords: nucl-ex, nucl-ex
Divisions: Faculty of Science and Engineering > School of Physical Sciences
Depositing User: Symplectic Admin
Date Deposited: 19 May 2022 13:48
Last Modified: 17 Oct 2023 13:20
DOI: 10.1016/j.physletb.2022.136957
Open Access URL: https://www.sciencedirect.com/science/article/pii/...
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3155126