학술논문
Shell evolution approaching the N=20 island of inversion: structure of 26Na
Document Type
Working Paper
Author
Wilson, G. L.; Catford, W. N.; Orr, N. A.; Diget, C. Aa.; Matta, A.; Hackman, G.; Williams, S. J.; Celik, I. C.; Achouri, N. L.; Falou, H. Al; Ashley, R.; Austin, R. A. E.; Ball, G. C.; Blackmon, J. C.; Boston, A. J.; Boston, H. C.; Brown, S. M.; Cross, D. S.; Djongolov, M.; Drake, T. E.; Hager, U.; Fox, S. P.; Fulton, B. R.; Galinski, N.; Garnsworthy, A. B.; Jamieson, D.; Kanungo, R.; Leach, K. G.; Orce, J. N.; Pearson, C. J.; Porter-Peden, M.; Sarazin, F.; Simpson, E. C.; Sjue, S.; Smalley, D.; Sumithrarachchi, C.; Svensson, C. E.; Triambak, S.; Unsworth, C.; Wadsworth, R.
Source
Subject
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Abstract
The levels in 26Na with single particle character have been observed for the first time using the d(25Na,p gamma) reaction at 5 MeV/nucleon. The measured excitation energies and the deduced spectroscopic factors are in good overall agreement with (0+1) hbar-omega shell model calculations performed in a complete spsdfp basis and incorporating a reduction in the N=20 gap. Notably, the 1p3/2 neutron configuration was found to play an enhanced role in the structure of the low-lying negative parity states in 26Na, compared to the isotone 28Al. Thus, the lowering of the 1p3/2 orbital relative to the 0f7/2 occurring in the neighbouring Z=10 and 12 nuclei -- 25,27Ne and 27,29Mg -- is seen also to occur at Z=11 and further strengthens the constraints on the modelling of the transition into the island of inversion.
Comment: 6 figures
Comment: 6 figures