Systematic study of the many-particle and many-hole states in

and around the Island of Inversion

- #N=Odd system -M. Kimura(Hokkaido)

Introduction: Island of InversionIsland of Inversion: N ～ 20 Ne, Na, Mg isotopes Topics: large deformation, mpmh config., shell gap quench

N=21 isotone: 31Ne(binding limit), 33Mg Topics: spin-parity, p-wave halo, neutron orbital

N=21 isotone•Odd-mass(neutron) system reveals neutron-orbital, shape coexistence in the Island

•The last neutron particle (hole) orbital has strong influence on nuclear properties

•In N=21 isotone, 0f7/2 and 0d3/2 orbials take part in the game

Island of Inversion

Theoretical Framework: AMD

A-body Hamiltonian

Parity projected Slater determinant

Single particle wave packets

Variational parameters

Gogny D1S

Theoretical Framework: AMDAngular momentum projection

GCMGenerator Coordinate: quadrupole deformation b

Hill-Wheeler eq.

Energy curves in and around the Island

• ph configuration depends on neutron #• Relative energy between ph states depends on the proton number

The Island

Spectrum of 32Mg

V. Tripathi, et. al., PRC77034310(2008).

Results: 0+ and 2+ states (N=20 isotones)

• Strongly deformed 2p2h takes over the ground state

• Note that 0p0h, 2p2h and 4p4h appear in the Island

• 4p4h (more deformed) also participates in.

• Some experimental evidences

Results: 0+ and 2+ states (Z=10,12 isotopes)

2p2h dominates in N=20, 22 system

4p4h (4hw)appears only in N=20 isotopes

Intermediate character

of N=18 isotopes

Precursor in N=18 system

Results: 1- and 3- states (N=20 isotones)

Great reduction of 3p3h energy

1p1h is not so sensitive to the proton number

Results: 1- and 3- states (Z=10,12 isotopes)

Great reduction of 1hw excitation energy

Due to the reduction, de-excitation is also

possible in the island

• Precursor in N=18 system

Introduction: Particle Hole Config. (N=19 System)1p-removal from 32AlD. Miller, et.al.,Phys. Rev. C 79, 054306 (2009)

31Mg

0p1h1p2h2p3h3p4h

M. K. Phys.Rev. C 75, 041302 (2007)

Jp = (3/2, 5/2)+

b-decays 33Na(N=22,g.s.) → 33Mg(g.s.)

33Mg(g.s.) → 33Al(N=20, g.s.)

Jp = 3/2-

magnetic-moment: m=-0.7456mN

1n-removal: p3/2

S. Nummela, et. al., PRC64, 054313 (2001)

V. Tripathi, et. al., PRL101,142504 (2008)

D. T. Yordarov, et. al., PRL99, 212501 (2007)

R. Kanungo, et. Al., PLB685, 253 (2010)

Introduction: Spin-parity of 33Mg(N=21)

Introduction: 1n Halo of 31Ne(N=21)1n-Removal Exp. : Large cross section : Observed large cross

section can be explained with small Sn and l=1,2

Large Reaction cross section M. Takechi, et. al., Nucl. Phys. A 834, (2010), 412

T. Nakamura, et. al., PRL103, 262501 (2009)

Halo?

Results: Energy Curve and PH Config. of 33Mg

33Mg

1p0h2p1h3p2h

4p3h

2p1h1p0h 3p2h 4p3h

Introduction: Particle Hole Config. (N=21 System)

33Mg

1p0h2p1h3p2h4p3h

Results: Spectrum of 33MgConsistent with magnetic moment exp. AMD underestimates number of very low-lying

statesSn=3.2MeV

Results: b-decay and Jp assignment33Na(4p2h) feeds 4p3h config.

33Na(4p2h)

33Mg*(4p3h)

Results: B(E2) of 33MgCoulomb Excitation Exp. : B.V. Pritychenko, et. al., PRC65,

061304(R) (2002). Large cross section for 485keV stateAuthors assumed Jp=5/2+ for the ground state (no information was available at

that time except for b-decay data that suggested positive parity)Large cross section does not contradict to AMD (Further exp. is required.)

Results: Spectrum of 31Ne

Sn=250keV

Same Jp with 33Mg, but much smaller Sn3/2+ is almost degenerated (Ex=120keV)

Summary and PlanSummary33Mg has negative-parity ground state with J=3/2AMD agrees with magnetic moment and COULEX

experiments, but contradict to b-decayb-decay of 33Na should feeds 4p3h config. of 33Mg31Ne also has negative-parity ground state with J=3/2 and very small Sn. J=3/2- is almost degenerated.

PlansSmall Sn, but no Halo ! (fault of AMD, RGM calc. to

see it)

p-n interaction dependence of level-ordering