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).

Neutron Halo Structure neutron 9 Li-core Neutron Halo 9 Li+n subsystem ⇒ unbound 9 Li+n+n ⇒ loosely bound n+n subsystem ⇒ unbound Borromean system B.V. Danilin et al. PRC43, 2835(1991)

Complex Scaled Cluster Orbital Shell Model 9 Li+n+n threshold 4 He+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 ) ＋ ψ JM =φ JM (V)+φ JM (T) ・ wave function ・ Core+n+n Hamiltonian ・ potential Gaussian-type potential V F core-n =V cnt +V ls S. Aoyama, K. Kato and K. Ikeda, PTP. Suppl. No.142 (2001).

Energy Convergence of 3/2 - state in 11 Li Channel of COSM (V-type) [1] (p 1/2 ) 2 [2] (p 1/2 ) 2 + (s 1/2 ) 2 [3] ・・・・・ Channel of ECM (T-type) l=L=S=0 9Li-n potential: HN1,δ= 0.245, δ p = n-n potential: Minnesota, u=0.95 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 (1s 1/2 ) 2 and (0p 1/2 ) 2 in 11 Li 1s 1/2 0p 1/2 10 Li 9 Li+n threshold Ground 3/2- state 11 Li 9 Li+n+n threshold (0p 1/2 ) 2 + (1s 1/2 ) 2 + ・・・ (1s 1/2 ) 2 + (0p 1/2 ) 2 + ・・・ Excited 3/2- state loosely bound state three-body resonance

Pairing excited 9 Li+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 9 Li-core Dipole oscillation K. Ikeda, INS Report JHP-7(1988). P.G. Hansen and B. Jonson, EPL4(1987).

Separation of the Strength Function for E λ -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 11 Li, 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 11 Li, we understand that the experimental peak is considered to be from the 10 Li+n breakup and the 9 Li+n+n breakup rather than the three-body resonance. Next problem We will study new Riken data.