TY - JOUR
T1 - Re-examining the transition into the N=20 island of inversion: structure of 30Mg
AU - Fernandez Dominguez, Beatriz
AU - Petri, Marina Kalliopi
AU - Paschalis, Stefanos
N1 - © 2018 Published by Elsevier B.V.
PY - 2018/4/10
Y1 - 2018/4/10
N2 - Intermediate energy single-neutron removal from
31Mg has been employed to investigate the transition into the N=20 island of inversion. Levels up to 5 MeV excitation energy in
30Mg were populated and spin-parity assignments were inferred from the corresponding longitudinal momentum distributions and γ-ray decay scheme. Comparison with eikonal-model calculations also permitted spectroscopic factors to be deduced. Surprisingly, the 0
2
+ level in
30Mg was found to have a strength much weaker than expected in the conventional picture of a predominantly 2p−2h intruder configuration having a large overlap with the deformed
31Mg ground state. In addition, negative parity levels were identified for the first time in
30Mg, one of which is located at low excitation energy. The results are discussed in the light of shell-model calculations employing two newly developed approaches with markedly different descriptions of the structure of
30Mg. It is concluded that the cross-shell effects in the region of the island of inversion at Z=12 are considerably more complex than previously thought and that np−nh configurations play a major role in the structure of
30Mg.
AB - Intermediate energy single-neutron removal from
31Mg has been employed to investigate the transition into the N=20 island of inversion. Levels up to 5 MeV excitation energy in
30Mg were populated and spin-parity assignments were inferred from the corresponding longitudinal momentum distributions and γ-ray decay scheme. Comparison with eikonal-model calculations also permitted spectroscopic factors to be deduced. Surprisingly, the 0
2
+ level in
30Mg was found to have a strength much weaker than expected in the conventional picture of a predominantly 2p−2h intruder configuration having a large overlap with the deformed
31Mg ground state. In addition, negative parity levels were identified for the first time in
30Mg, one of which is located at low excitation energy. The results are discussed in the light of shell-model calculations employing two newly developed approaches with markedly different descriptions of the structure of
30Mg. It is concluded that the cross-shell effects in the region of the island of inversion at Z=12 are considerably more complex than previously thought and that np−nh configurations play a major role in the structure of
30Mg.
UR - http://www.scopus.com/inward/record.url?scp=85044655836&partnerID=8YFLogxK
U2 - 10.1016/j.physletb.2018.02.002
DO - 10.1016/j.physletb.2018.02.002
M3 - Article
SN - 0370-2693
VL - 779
SP - 124
EP - 129
JO - Physics Letters B : Nuclear, Elementary Particle and High-Energy Physics
JF - Physics Letters B : Nuclear, Elementary Particle and High-Energy Physics
ER -
