1 / 32

軽い核におけるテンソル相関と 短距離相関の役割

軽い核におけるテンソル相関と 短距離相関の役割. 明　孝之　　　大阪大学 ＲＣＮＰ. Tensor correlation for He and Li isotopes in Tensor-Optimized Shell Model (TOSM) Short-range correlation by Unitary Correlation Operator Method (UCOM) TOSM + UCOM with bare interaction. 核子と中間子の多体問題の統一的描像に向けて＠ RCNP 2007. 12.14-15.

kisha
Download Presentation

軽い核におけるテンソル相関と 短距離相関の役割

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. 軽い核におけるテンソル相関と短距離相関の役割軽い核におけるテンソル相関と短距離相関の役割 明　孝之　　　大阪大学 ＲＣＮＰ • Tensor correlation for He and Li isotopes in Tensor-Optimized Shell Model (TOSM) • Short-range correlation by Unitary Correlation Operator Method (UCOM) • TOSM + UCOM with bare interaction 核子と中間子の多体問題の統一的描像に向けて＠RCNP2007. 12.14-15

  2. Motivation (tensor force) • Tensor force (Vtensor) plays a significant role in the nuclear structure. • In 4He, • ~ 80% (GFMC) R.B. Wiringa, S.C. Pieper, J. Carlson, V.R. Pandharipande, PRC62(2001) • We would like to understand the role of Vtensor in the nuclear structure by describing tensor correlation explicitly. • model wave function (shell model and cluster model). • spatial properties, p-h correlation, … • Spectroscopy of neutron-rich nuclei : He and Li isotopes

  3. Variational calculation in real space Green’s function Monte Calro mass12 C.Pieper, R.B.Wiringa, Annu.Rev.Nucl.Part.Sci.51(2001) R.B.Wilinga,S.C.Pieper,J.Carlson, V.R.Pandaripande, PRC62(2000)014001. a-a structure

  4. Tensor-optimized shell model (TOSM) • Tensor correlation in the shell model type approach. • Configuration mixingwithin 2p2h excitationswith high-L orbitTM et al., PTP113(2005) TM et al., PTP117(2007) T.Terasawa, PTP22(’59)) • Length parameters such as are determined independently and variationally. • Describe high momentum component from VtensorCPP-HF by Sugimoto et al,(NPA740) / Akaishi (NPA738) CPP-RMF by Ogawa et al.(PRC73), CPP-AMD by Dote et al.(PTP115) 4He

  5. Hamiltonian and variational equations TM, Sugimoto, Kato, Toki, Ikeda PTP117(’07)257 • Effective interaction : Akaishi force (NPA738) • G-matrix from AV8’ with kQ=2.8 fm-1 • Long and intermediate ranges of Vtensor survive. • Adjust Vcentral to reproduce B.E. and radius of 4He

  6. 4He in TOSM Shrink Length parameters Lmax Higher shell effect good convergence

  7. Pion exchange interaction vs. Vtensor Involve large momentum Delta interaction Tensor operator Yukawa interaction - Vtensor produces the high momentum component.

  8. 4He in TOSM 4 Gaussians instead of HO c.m. excitation = 0.6 MeV • 0 of pion nature. • deuteron correlation with (J,T)=(1,0) Cf. R.Schiavilla et al. (GFMC) PRL98(’07)132501

  9. LS splitting in 5He with tensor corr. • T. Terasawa,PTP22(’59) • S. Nagata, T. Sasakawa, T. Sawada R. Tamagaki, PTP22(’59) • K. Ando, H. Bando PTP66(’81) • TM, K.Kato, K.Ikeda PTP113(’05) • Orthogonarity Condition Model (OCM) is applied.

  10. Phase shifts of 4He-n scattering

  11. Tensor correlation in 6He Ground state Excited state

  12. 6He in coupled 4He+n+n model Theory With Tensor • (0p3/2)2 can be described in Naive 4He+n+n model • (0p1/2)2 loses the energy Tensor suppression in 0+2

  13. Characteristics of Li-isotopes Halostructure • Breaking of magicity N=8 • 10-11Li, 11-12Be • 11Li … (1s)2 ~ 50%.(Expt by Simon et al.,PRL83) • Mechanism is unclear 11Li

  14. Pairing-blocking : K.Kato,T.Yamada,K.Ikeda,PTP101(‘99)119,Masui,S.Aoyama,TM,K.Kato,K.Ikeda,NPA673('00)207. TM,S.Aoyama,K.Kato,K.Ikeda,PTP108('02)133, H.Sagawa,B.A.Brown,H.Esbensen,PLB309('93)1.

  15. 11Li in coupled 9Li+n+n model • System is solved based on RGM TOSM • Orthogonality Condition Model (OCM) is applied.

  16. 11Li G.S. properties (S2n=0.31 MeV) Rm Simon et al. P(s2) Tensor +Pairing TM, K.Kato, H.Toki, K.Ikeda, PRC76(’07)024305 TM. Y.Kikuchi, K.Kato, H.Toki, K.Ikeda, sumitted to JPG

  17. Charge Radii of Li isotopes 9Li G RC-2n Charge Radius 11Li 9Li Tensor +Pairing Inert core Expt. (Sanchez et al., PRL96(2006))

  18. Coulomb breakup strength of 11Li No three-body resonance E1 strength by using the Green’s function method +Complex scaling method +Equivalent photon method (TM, Aoyama, Kato, Ikeda, PRC63(’01)054313) • Expt: T. Nakamura et al. , PRL96,252502(2006) • Energy resolution with =0.17 MeV.

  19. Tensor & Short-range correlations • Tensor correlation in TOSM • 2p2h mixing optimizing the particle states (radial & high-L) • Short-range correlation • Short-range repulsion of the bare NN force in the relative wave function of nuclei • Unitary Correlation Operator Method (UCOM) H. Feldmeier, T. Neff, R. Roth, J. Schnack, NPA632(1998)61 T. Neff, H. Feldmeier NPA713(2003)311

  20. Unitary Correlation Operator Method short-range correlator Bare Hamiltonian Shift operator depending on the relative distance r H. Feldmeier, T. Neff, R. Roth, J. Schnack, NPA632(1998)61

  21. Short-range correlator : C Originalr2 1GeV repulsion C

  22. 4He in UCOM (Afnan-Tang) C

  23. Charge form factor and Corr. Func. Form Factor 1E (0s)4 C

  24. 4He in TOSM+UCOM Central+ LS+Tensor (Kamada et al. PRC64) R. Roth et. al , PRC72(2005)034002

  25. Summary • Tensor correlation in nuclei • Tensor-optimized shell model (TOSM) • He isotopes, Li isotopes • Short-range correlation • Unitary Correlation Operator Method (UCOM) • In TOSM+UCOM, we can study the nuclear structure starting from the bare interaction • Spectroscopy of light nuclei (p-shell region)

  26. 4He in TOSM+UCOM Vnn : AV8’ • 0- of pion nature • deuteron corr. with (J,T)=(1,0) c.m. excitation = 0.4 MeV

  27. Properties of 4He (Kamada et al. PRC64)

  28. Property of the tensor force • Centrifugal potential (1GeV@0.5fm) pushes away the L=2 wave function.

  29. Form of R+ in UCOM 1E Original C Afnan-Tang : centralonly about 1GeV repulsion Functional form given by referring to the Deuteron’s exact case

  30. 16O with UCOM (Afnan-Tang) C

  31. 6He with 4He+n+n model Pairing correlation is important V V+T K.Ikeda, NPA538(1992)355 S.Aoyama, S. Mukai,K.Kato, K. Ikeda, PTP93(1995)99.

  32. Q-moment of Li-isotopes Vanish due to 0+ state of 2n 9Li G RC-2n 2n~0+ Varga et. al Kanada-En’yo

More Related