Unified studies of light neutron-excess systems from bounds to continuum

1. Unified studies of light neutron-excess systems from bounds to continuum －Structural changes and Reaction dynamics in Be isotopes － Makoto Ito Department of Pure and Applied Physics, Kansai University I. Introduction II. Framework III. Various structures in 12Be and Be isotopes IV. Enhancements induced by level crossing V. Summary and feature plan

2. IKEDA Diagram Cluster structures in 4N nuclei Ikeda’s Threshold rules Molecular structures will appear close to the respective cluster threshold. H.O. quanta N <N> ± DN Be isotopes ～ 34.6 ± 5.9 Molecular Orbital : Itagaki et al,…. α-Particle ⇒ building block p― 3H+p ～ 20 MeV Clustering phenomena is generated by a huge mixing of shell model configuration. s+ PRC61,62 (2000)

3. Studies on Exotic Nuclear Systems in (Ex,N, Z,J) Space Slow RI beam Unbound Nuclear Systems 1. Structures of 8～16Be 2. Breakup of 10,12Be Decays in Continuum Is Threshold Rule valid ?? Ex. energy Structural Change Low-lying Molecular Orbital : p―、s＋‥ N ( N,Z ) : Two Dimensions

4. Extension of microscopic cluster model (Test calculation for 10Be) 10Be=a+a+N+N a 6He 5He 5He Mol. Orb. Combine Unified model between M.O. and He clusters :PLB588 (04) ... S + + Y = C2 C3 C1 S, Ci: Variational PRM. 0Pi (i=x,y,z) Coupled channels with Atomic orbitals Absorbing B.C. Scattering B.C. Tr. densites <CL| r| MO> Decay widh PTP113 (05) 10Be→ a+6He Breakup a+6He Cross sections PLB636 (06) ｰi W(R)

5. Femto Molecules ：12Be=a+a+4N NN: Volkov No.2+G3RS 7He 5He Covalent Ionic (0pR)(0pL)(s+)2 a+8He ⇒ 6He+6He 6He 6He 06+ 05+ Atomic 04+ 6He + 6He Neutrons’ ex. 03+ a + 8He Clusters’ Relative ex. 8He (p-)2(p-)2 Ionic 02+ Various structures are generated by excitation of a-aand neutron degree of freedom. 01+ (p-)2 (s+)2

6. Be isotopes from bounds to continuums : Jp = 0+ 8Be 10Be 12Be 14Be 16Be Deformed states (Clusters) Excitation of a-a rel. motion yHe xHe Compact states (Shell model)

7. We can discuss reaction dynamics in connection to level crossing scheme. Level Crossings scheme in Be isotopes C + D Internal States A + B Energy Clusters ( Intruder ) Level Crossing Asymptotic States Compact ( Normal ) Small Large Core-Core distance

8. Level Crossings in 12,14Be=a+a+XN (X=2,6) 10Be 14Be (0p)2(sd)4 Level Crossing a + 6Heg.s. 8Heg.s. + 6Heg.s. (sd)2 Level Crossing (0p)2 (0p)4(sd)2

9. GTCM + Absorbing Boundary Condition : PLB (2006) Energy spectra ( Jp = 0+ ) Adiabatic surfaces (Jp = 0+) a+6He(21+) Cluster ｰi W(R)

10. Nuclea breakup : 10Be +12C ⇒ 10Be(0+ conti.)+ 12C (CDCC cal.) Smat.( Conti.←G.S. ) Smat.( Poles ← G.S.) S-matrices to Poles S-matrices to continuums 03+ 03+ 04+ 04+

11. Reaction path in 10Be → xHe + yHe Breakup reaction (Positive Parity) 10Be(0+) → [ a + 6He(21+) ] 0+ Reaction Path in Breakup 03+ × 01+ Non-adiabatic tr. is main process. 01+ → 03+ is the dominant transition.

12. Level Crossing in 12Be (2) : breaking of N=8 magic number and level crossing Correlated AESs AESs with full coupling a + 8Heg.s. a + 8Heg.s. Correlation Coupling with all configurations Conjunction G.S.⇔ a+8He [(0p)4(sd)2] (p-)2 (s+)2 [(0p)6] G.S. (p-)2 (p-)2 Lowest minimum smoothly connected to a+8He g.s. ⇒ Formation of adiabatic conjunction

13. Monopole transition of 12Be Adiabatic transition is main process in monopole transition. 8He 03+ 01+ → 03+ is enhanced. (p-)2 (s+)2 01+

14. Contents of present report 1. Unified studies form bounds to continuums in Be isotopes 2.Reactions with large amplitudes in connection to adiabatic energy surfaces Results 1. There appears a wide variety of structures in excited states (Cluster + excess N) 2. Enhancements occur depending on the structures of AESs. 10Be : Non-adiabatic path is dominant in monopole breakup . 12Be : Adiabatic path is dominant in monopole breakup (breaking of N=8 magic). Feature studies Recently, we have just succeeded in extending the model to general two centers. Extension to SD shell ⇒O=a+12C+XN、Ne=a+16O+XN Generalities and Specialities : hybrid structures of clusters + excess neutrons in O and Ne