Nuclear moments of the low-lying isomeric 1+ state of 34Al: Investigation on the neutron 1p1h excitation across N=20 in the island of inversion

© 2018 The Author(s) The nuclear g factor and quadrupole moment (Q s ) have been measured for the low-lying isomeric 1 + state of 34 Al, using the β-detected nuclear magnetic resonance (β-NMR) and quadrupole resonance (β-NQR) methods. Spin-polarized 34 Al isotopes were produced in a one-neutron pickup reaction induced by a 36 S beam on a 9 Be target at a kinetic energy of 77.5 MeV/nucleon, and were collected with the LISE fragment separator at GANIL. The measured g factor (|g| in a range of 1.757±0.014) and quadrupole moment (|Q s |=38(5) mb) are in good agreement with shell-model calculations using effective interactions. The similarity between the g factor of 34m Al and that of 32 Al confirms a dominant neutron 2p1h configuration π(d 5/2 ) −1 ⊗ν(d 3/2 ) −1 (f 7/2 ) 2 of 34m Al. In addition, the enhanced quadrupole moment of 34m Al relative to that of 32 Al suggests that the neutron 1p1h excitation across the N=20 shell gap introduces extra nucleon–nucleon correlation and deformation.

Publication year:2018

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Authors:International

Authors from:Higher Education

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