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轻核的组态问题 (17Ne 为例 ) 唯象计算 可能的 微观研究. psd 壳层滴线核性质的壳模型研究 ----- 丰质子核的结构. 亓冲 北京大学技术物理系. 11 Li. Common features: Loosely Bound s or p wave valence nucleons. H. Simon et al, PRL 83, 496 (1999). Exotic phenomena in psd shell nuclei. 11Be, 14B, 17C, 19C etc. 6He, 11Li, 14Be, 17B etc.
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轻核的组态问题 (17Ne为例) • 唯象计算 • 可能的微观研究 psd壳层滴线核性质的壳模型研究 -----丰质子核的结构 亓冲 北京大学技术物理系
11Li • Common features: • Loosely Bound • s or p wave valence nucleons H. Simon et al, PRL 83, 496 (1999) Exotic phenomena in psd shell nuclei 11Be, 14B, 17C, 19C etc. 6He, 11Li, 14Be, 17B etc.
17Ne: dependent on the configuration of the valence proton pair Shell model calculations may be helpful… L.V. Grigorenko, PRC71, 051604(R) (2005) M. Chromik et al, PRC66, 024313(2002) Proton halo? • 8B (1p1/2, ε=138keV) : probably not • 17F* (2s1/2,, ε=105keV ): yes • 17Ne(ε2p=940keV ) : unknownconfiguration : unknown
Problems of the microscopic approach: • Model space with a core (with core polarization effect):numerically not feasible for non-degenerate systems • No core shell model (no hole state):dependent on h ω and the space;convergence problem Shell-model description: Heff=PHP+PHΩQ P : model space (psd shell) Q : excluded space (1s+fp+…) Ω: wave operator • Realistic HamiltonianMK, WBT • Microscopic HamiltonianCD-Bonn... +Unitary transformation
11Li Intruder S. Shimoura et al, PLB 654, 87 (2007) H. Simon et al, PRL 83, 496 (1999) Problems of the realistic Hamiltonian: • Constructed from stable nucleistill valid for drip line nuclei? • Truncations (0+1 h ω for MK)effect of intruder states becoming important at drip line 3) Sensitive to effective operators
Breaking effect Two body one body 2s1/2 5)Charge breaking effect • Isospin symmetry (mirror symmetry)
13C Improved realistic Hamlitonian (WB*) • WBT (for pp＋p-sd) + USDB (for sd); • Reduced shell gap to fit low-lying states of 13C-13N; • Charge breaking effect;Coulomb + CSB strong force (from CD-Bonn) +Thomas-Ehrman shift • Renormalization effect of h ω-nonconserving interactione.g., pp-sd • COM correction (the method of Lawson)
MK: WBT: Calculation (1) • WB* in 0-3h ω psd space • WBT and MK in 0+1 h ω psd space • Parallel shell-model code + PKU cluster Construction of the many-body Hamiltion; Lanczos diagonalization -> Further applications?
Calculations (2) Improved performance for EM properties
17Ne 15O Calculations (3) Spectral description not so good(effect of h ω-nonconserving interaction ?)
beta-decay analysis : the state should have 50% more 1s1/2 component than that of 17N. D.J. Millener, PRC,55, R1633 (1997). Experiment Calculations (4) Configurations of the valence proton pair in 17Ne: sensitive to the Thomas-Ehrman shift !! g.s. 3/2-
Calculations (5) Further charge-breaking effect? UNDERSTOOD UNDERSTOOD 3+ 3+ ? WB* K.I. Hahn et al, PRC54, 1999(1996)
TTS Kuo,PRL 78 (2708)1997 K Ogawa, PLB 464(157)1999 Origins? Critical role played by the CSB effect
TTS Kuo,PRL 78 (2708)1997 K Ogawa, PLB 464(157)1999 Summary • psd shell model calculations on 17Ne; • The Thomas-Ehrman shift can enhance the 1s^2 component of the valence proton pair; • An example with strong Coulomb effect on the configuration; • Microscopic origin of the Thomas-Ehrman shift and the CSB effect?
知其所以然？ • No-core shell modelLee-Suzuki transformationto the shell model basis (no hole state) 2h ω T. Dytrych et al, PRL, 98, 162503 (2007) 0h ω +2h ω correction
Two step unitary transformation? • Core nucleons+ valence nucleons + 2h ω corection Core : no hole state + mean field potential for the single particle energy? • 0+2 2h ω : to heavier nuclei? • Step:1) Unitary transformation in momentum space 2)Lee-Suzuki transformation with P=core space +(0+2) h ω
(2)Radial Properties • Shell model plus coupled-channel?
