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Coulomb Breakup and Pairing Excitation of Two-Neutron Halo Nucleus 11 Li. Niigata University S . Aoyama RCNPT. Myo Hokkaido UniveristyK. Kato RikenK. Ikeda. S. Aoyama, K. Kato, T. Myo and K. Ikeda, PTP 107(2002). T. Myo, S. Aoyama, K. Kato and K. Ikeda, PLB576(2003). - PowerPoint PPT Presentation
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Coulomb Breakup and Pairing Excitation
of Two-Neutron Halo Nucleus 11Li
Niigata University S . AoyamaRCNP T. MyoHokkaido Univeristy K. KatoRiken K. Ikeda
S. Aoyama, K. Kato, T. Myo and K. Ikeda, PTP 107(2002).
T. Myo, S. Aoyama, K. Kato and K. Ikeda, PLB576(2003).
Neutron Halo Structure
neutronneutron
9Li-core
Neutron Halo
9Li+n subsystem ⇒ unbound
9Li+n+n ⇒ loosely bound
n+n subsystem ⇒unbound
Borromean system
B.V. Danilin et al. PRC43, 2835(1991)
Complex Scaled Cluster Orbital Shell Model
9Li+n+nthreshold
4He+n+n: S. Aoyama, S. Mukai, K. Kato and K. Ikeda, PTP93 (1995).
Many higher orbits
Gamow Shell Model (Complex Scaled Shell Model)N. Michel, W. Nazarewicz, M. Ploszajczak , J. Okolowicz, PRC67(2003).R. ID Betan, R.J. Liotta, N. Sandulescu, T. Vertse, PRL89(2002).
E. Balslev and J.M. Combes, Commun. Math. Phys. 22(1971), 280.J. Aguilar and J.M. Combes, Commun. Math. Phys. 22(1971), 269.
Proof of ECR for CSM was given in
Giraud and Kato, Ann. of Phys.308(2003).
Giraud et al., J. Phys. A37(2004).
Gamow Shell Model is also based on ECM.
Core-n: Folding potential
n-n: Minnesota(u=0.95)
V-type T-type
Cluster Orbital Shel Model (Hybrid TV model )
+ψJM=φJM(V)+φJM(T)
・ wave function
・ Core+n+n Hamiltonian
・ potential
Gaussian-type potential
VFcore-n=Vcnt +Vls
S. Aoyama, K. Kato and K. Ikeda, PTP. Suppl. No.142 (2001).
Energy Convergence of 3/2- state in 11Li
Channel of COSM (V-type)[1] (p1/2)2
[2] (p1/2)2+ (s1/2)2
[3] ・・・・・
Channel of ECM (T-type) l=L=S=0
9Li-n potential: HN1,δ= 0.245, δp= 0.0866n-n potential: Minnesota, u=0.95
V-type
V-type T-type
+
COSM
Hybrid -TV
S. Aoyama, K. Kato and K. Ikeda, PTP. Suppl. No.142 (2001)
28 shell-like orbits (l=14)
Shell-like bases can not accurately describe halo! !
Partners of mixed configurations of (1s1/2)2 and (0p1/2)2 in 11Li
1s1/2
0p1/2
10Li
9Li+n threshold
Ground 3/2- state
11Li
9Li+n+nthreshold
(0p1/2)2+ (1s1/2)2 + ・・・
(1s1/2)2+ (0p1/2)2 + ・・・
Excited 3/2- state
loosely bound state
three-body resonance
Pairing excited 9Li+n+n resonance
Calculations with the Hybrid TV model
A peak is observed at 0~1MeV in the Coulomb (E1) breakup experiments.
⇒ Soft dipole resonance?
(E1 or 1- resonance)
Neutron Halo
9Li-core
Dipole oscillation
K. Ikeda, INS Report JHP-7(1988).
P.G. Hansen and B. Jonson , EPL4(1987).
Separation of the Strength Function for Eλ-trandition
Complex scaled Hamiltonian
In this calculation, we deveop COSM in order to include the core excitation.
No three-body resonant states which correspond to the soft dipole mode!
Summary(1)As an excited resonance in 11Li, by using CSM, we predict the pairing type three-body resonance at low energy region (0~ 1MeV).
(2)For the peak of the E1 strength in 11Li, we understand that the experimental peak is considered to be from the 10Li+n breakup and the 9Li+n+n breakup rather than the three-body resonance.
Next problem
We will study new Riken data.