Search for resonances in $^4$n, $^7$H and $^9$He via transfer reactions
NESTER PTH, Détecteur MUST International audience Investigation of unbound nuclear systems 9He, 7H and 4n was performed at GANIL-SPIRAL using the 8He beam at 15.3 A MeV and a CD2 target. The missing mass spectra were deduced from kinetic energies and emission angles of light ejectiles detected by th...
Published in: | AIP Conference Proceedings |
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Main Authors: | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |
Other Authors: | , , , , , , , |
Format: | Conference Object |
Language: | English |
Published: |
HAL CCSD
2006
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Subjects: | |
Online Access: | http://hal.in2p3.fr/in2p3-00157522 https://doi.org/10.1063/1.2746575 |
Summary: | NESTER PTH, Détecteur MUST International audience Investigation of unbound nuclear systems 9He, 7H and 4n was performed at GANIL-SPIRAL using the 8He beam at 15.3 A MeV and a CD2 target. The missing mass spectra were deduced from kinetic energies and emission angles of light ejectiles detected by the Silicon array MUST. In addition to previously known low-lying narrow resonant states in 9He, the d(8He,p) reaction displays a structure just above neutron emission threshold, identified with the “true” ground state of 9He. The analysis of angular distributions shows that the inversion of s1/2 and p1/2 neutron shells previously observed in 11Be and 10Li also exists in the lightest N=7 isotone 9He. The d(8He,3He) and d(8He,6Li) reactions were used to search for resonant states in the t+4n (7H) and 4n systems, respectively. The missing mass spectrum of the 4n system does not give evidence for the existence of a bound “tetraneutron”. However the comparison with the results of 5-body phase-space calculations emphasizes the existence of correlations in the 4n system. The broad structure observed at ~=2 MeV above the t+4n emission threshold is proposed to be the ground state of 7H |
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