1 / 33

少数体系アプローチの研究と今後の課題 Few-Body Approach and Future Problems

少数体系アプローチの研究と今後の課題 Few-Body Approach and Future Problems. Y. Suzuki (Niigata). ・ NN interaction is characterized by strong short-range repulsion and long-range tensor force ・ Accurate solution is possible for FBS ・ The interplay between BB interaction and dynamics of

tod
Download Presentation

少数体系アプローチの研究と今後の課題 Few-Body Approach and Future Problems

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. 少数体系アプローチの研究と今後の課題 Few-Body Approach and Future Problems Y. Suzuki (Niigata) ・NN interaction is characterized by strong short-range repulsion and long-range tensor force ・Accurate solution is possible for FBS ・The interplay between BB interaction and dynamics of strongly interacting few-body quantum systems is revealed ・The effect of three-body forces is one of current issues Present status and future direction on • Ab initio calculation in FBS • Towards more-particle systems • Continuum problems • 4. Breakup reactions

  2. NN potential Even partial waves Odd partial waves

  3. 1.1 Various accurate methods for bound states Benchmark calculation for the ground state of 4He FY CRCGV, SVM, HH (Variational) GFMC NCSM, EIHH (P-space effective int.) AV8’ H.Kamada et al. PRC64 (2001)

  4. Correlation functions for s-shell nuclei Triplet even Singlet even AV8’ Y. Suzuki, W. Horiuchi, arXiv (2008)

  5. Correlation functions(continued) Triplet odd Coulomb

  6. Density 1.2 First excited state of 4He Inelastic electron scatt. form factor 3N+N clusterstate Hiyama et al. PRC70 (2004)

  7. 3N + N structure  J: 1/2 + 1/2 + 0 = 0, 1 T: 1/2 + 1/2 = 0, 1 Quartets: Inversion doublets: J: 1/2+ 1/2 + 1 = 0, 1, 2 ± Questions arising from 3N+N clusters with spins Asymmetric clusters Parity inverted state E.g. Ammonia molecule of NH3 Horiuchi,Ikeda: PTP 40(1968)

  8. Quartets, Negative parity partners, 0-0 and 0-1 level spacing 1.3 Energy levels of 4He W.Horiuchi et al. PRC78 (2008)

  9. Spectroscopic amplitude (SA) Only 02+0 has a peak near 3N surface, indicating a resonance W.Horiuchi et al. PRC78 (2008)

  10. Width of 0- : 0.61 MeV (Cal) 0.84 MeV (Exp) 3N+N cluster structureInversion doublet Negative parity partners Peak position Centrifugal barrier

  11. 1.4 Three-body forces See Proceedings of FM 50 (2007) ・Binding energies ・The ground state of 10B (1+ or 3+) S.C.Pieper et al. PRC66 (2002) E.Caurier et al., PRC66 (2002) ・Scattering observables Nd scattering

  12. Effects of three-body forces: Correct spin-parity of 10B ～ 20MeV contribution for 12C S.C.Pieper et al. Proc. of FM50

  13. 1.5 Momentum distribution --- sensitive to short-range and tensor correlations--- Dueteron: D-wave fills the dip of S-wave Effects of short-range repulsion 6He: nn (pp) pair 6Li: np pair W. Horiuchi et al. PRC76 (2007) T. Suda et al. 6He(p,dn)4He 理研.08

  14. pn (lines) pp (symbols) Ｑ=0：　Back to back geometry R. Schiavilla et al. PRL98 (2007) 理研.08

  15. Dependence on Q Q=p1+p2 q=(p1-p2)/2 pn (lines) 4 pp (symbols) 1 R.B. Wiringa et al. PRC78 (2008) R. Subedi et al. Science 320 (2008) Exp. for 12C 理研.08

  16. 1.6 Accurate calculations needed to explore YN and YY interactions in Hypernuclei Interactions are poorly known experimentally ΛN-ΣN coupling, H.Nemura et al. PRL94 (2005)

  17. 2 Extension to more-particle systems ・GFMC (A～12) ・NCSM, UMOA (P-space effective interaction) Intruder states (e.g. Excited 0+ states of 12C and 16O) Slow convergence ・Transformation to milder interaction (indep. of P and Q) UCOM(Unitary transf., cluster exp.) Transcorrelated method (Similarity transf.) ・Semi-microscopic model Assuming a core nucleus or a cluster ・DFT

  18. 2.1 GFMC GFMC propagation requires huge storage of memory ～ 3A-1 2A 2A 12C(A=12) ～3×1012 (3兆） S.C.Pieper et al. PRC66 (2002)

  19. 2.2 NCSM Convergence for intruder states is slow Huge size of memory is required 12C Nmax=8 M=0 states in m-scheme Basis dimension 594,496,743 (6億） No. of nonzero matrix elements for 2B potentials 539,731,979,351 (5400億） 01 02 P. Maris et al. arXiv (2008)

  20. 2.3 Transcorrelated Method E-indep. effective interaction eliminating short-range repulsion Separation of short-range repulsion Choosing f(r) to eliminate W HTC is indep. of P and Q, non-Hermitean. Energy minimization is not applicable. Y.Suzuki et al. PTP113 (2005)

  21. 2.4 Semi-microscopic model Assuming clusters Phenomenological interaction is used Pauli-forbidden states E.Hiyama et al. PRC74 (2006)

  22. Exp. -7.27 0.38 MeV Ambiguity in cluster potentials ---RGM formalism--- Energy-indep. nonlocal potential 12C=3αmodel Dep. of E on phase-equivalent α-α potentials Different off-shell behavior Y. Suzuki et al. PLB659 (2008)

  23. 2.5 Density Functional Theory P. Hohenberg, W. Kohn, PR136 (1964) W. Kohn, L.J. Sham, PR140 (1965)

  24. Is the DFT justifiable for nuclei? Critical difference between electron gasses and nuclei Self-bound system with no external (s.p.) potential Correlation functions are basic variables Y. Suzuki, W. Horiuchi, arXiv (2008)

  25. 3.1 Application of discretized states to continuum problems ・Strength function CSM, LITM ・Scattering phase shifts Effects of three-body forces in α+n scattering phase shifts K.M. Nollett et al. PRL99 (2007)

  26. 3.2 Complex Scaling Method 4He+n+n model for 6He T.Myo et al. PRC63 (2001)

  27. 3.3 Lorentz Integral Transform method Invert Lorentz integral transform to obtain R or σ V.D.Efros et al. PLB338 (1994)

  28. 4He photo-absorption cross section Proc. of FM 50 S.Quaglioni et al. PLB652 (2007)

  29. 3.4 Scattering phase shift ---correcting spectroscopic amplitude with Green’s function (SAGF)--- α+n scattering effective force (central+LS) R-matrix (lines) SAGF (symbols) Study with realistic interactions is in progress

  30. 4.1 Breakup reactions of halo nuclei Breakup effects of fragile nucleus Elastic scattering of 6He on 12C α+ n + n three-body model for 6He Continuum-discretized states Coupled-channel calculation (cdcc) T. Matsumoto et al. PRC70 (2004)

  31. 40 MeV/nucleon Folding Eikonal approx.: N-12C optical potential Full Glauber model: 3α microscopic cluster model w.f. for 12C NN profile function Breakup effects are taken into account by Glauber- and Eikonal-model calculations VMC wave function for 6He B. Abu-Ibrahim et al. NPA 728 (2003)

  32. Coulomb-corrected eikonal model J. Margueron et al. NPA703 (2002): P. Capel et al. PRC78 (2008) 6He breakup on 208Pb at 240 MeV/A Description of the elastic breakup reaction of two-neutron halo nucleus Challenging four-body problemincluding continuum final states ・How to solve ・Final-state interaction ・Extraction of E1 strength function or effects of other multipoles D. Baye et al. submitted T. Aumann et al. PRC59 (1999)

  33. Hoping for 1. Fundamental and Breakthrough Works 2. Center for Discussions and Facilities 3. Positions for Young Promising Physicists Example: α＋α S-wave scattering phase shifts with realistic potentials ～ 4000 (Nα)2 times Time(α+n) Time(α+n)=0.1 day on a PC Nα=10 at least 40,000 days on a single processor Demand for a number of parallel processors

More Related