Sam Tabor Florida State University

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Intruder states approaching the Island of
Inversion
Sam Tabor - Florida State University
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30Al FROM THE 18O(14C,pn?) REACTION
(7-)?
(7-)?
(6-)?
(5-)?
(4-)?
30Al
30Al
T. Hinners et al., Phys. Rev. C 77, 034305 (2008)?
N 17
3
15
19
WBP-a
P.C. Bender et al., Phys. Rev. C 80, 014302 (2009)
GAMMASPHERE MICROBALL (2009)
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OCCUPATION PROBABILITIES WITH WBP-a AND WBP-b
INTERACTIONS
Predicted energies agree well for 1p-1h states.
3- 4- doublet have similar wavefunctions.
2p-2h states overpredicted by 2 MeV. WBP-b is
closer to believed p f7/2 x ? f7/2 configuration.
Compared to original WBP interaction (for A 20),
the f7/2 shell is lowered by 1.8 MeV in both
WBP-a and WBP-b. In WBP-a, the p3/2 orbital is
also lowered 0.5 MeV.
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WBP-a interaction also works rather well for the
1p-1h (relative to ground state configuration)
intruder states.
Narrow second 2177 keV line in thick target
experiment implies a long lifetime for the 7489
keV state, i.e. a multi-intruder configuration.
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SYSTEMATICS OF LOWEST FP INTRUDER STATES
T. Hinners et al., Phys. Rev. C 77, 034305 (2008)?
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SYSTEMATICS OF LOWEST FP INTRUDER STATES
N - Z 2
N - Z 4
T. Hinners et al., Phys. Rev. C 77, 034305 (2008)?
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END NOTES
Intruder states fall with increasing N Z
approaching the Island of Inversion.
More comprehensive spectroscopic techniques are
needed to explore these excited intruder states.
The shell model using the WBP-a interaction
reproduces the 1 particle 1 hole states in this
region rather well, but not the 2p-2h states.
More spectroscopic information from nuclei with
larger N Z is needed to better determine the
interaction and test its dependence on neutron
excess.
The energies of 4- 1p-1h states with the same
N Z are equal to 10-20 keV, an order of
magnitude better accuracy than the best theories.
Is this leading us to a more comprehensive
theory or just a fluke?
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SHELL MODEL UNIVERSAL S-D INTERACTION
Differences between theoretical and experimental
ground-state binding energies. Island of
Inversion appears in red and orange.
USDA interaction
B. Alex Brown and W. A. Richter, Phys. Rev. C74,
034315 (2006)?
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CHANGING SHELL GAP
N19
Y. Utsuno et al., PRC70,044307 (2004)?
T. Otsuka, Eur. Phys. J. A 20, 69 (2004)?