VIEWS: 2 PAGES: 28 POSTED ON: 9/12/2012
Deformed hypernuclei with the Skyrme-Hartree-Fock approach Xian-Rong Zhou Department of physics, Xiamen University, Xiamen, China 9th, Feb. 2012, Tokai 1 Outline Introduction Extended deformed Skyrme- Hartree-Fock (DSHF) Results Summary 2 Introduction Why do we study hypernuclei? Nucleon-nucleon interaction Hyperon-nucleon interaction Multistrange system Neutron star 3 Present Status of Hypernuclear Spectroscopy (2006) O. Hashimoto and H. Tamura, Prog. Part. Nucl. Phys. 57 (2006) 564. 4 Theoretical studies Studies based on spherical symmetry: 1. Relativistic mean-field model (RMF) 2. Skyrme Hartree-Fock model (SHF) 3. Woods-Saxon potential + YN interaction 4. Few-body theory 5 Theoretical studies Deformed calculations: Deformed HF with nonrealistic interaction: T. H. Ho and A.Volkov, Phys. Lett. B30, 303, 1969. W. H. Bassichis, A. Gal, Phys. Rev. C1, 28, 1970. J. Zofka, Czech, J. Phys. B30, 95, 1980. Nilsson Model: assume the same deformation for core and hypernuclei: K. Hagino, Phys. Rev. C63, 044318, 2001 Deformed SHF with Microscopic YN int. (self-consistent) X.-R. Zhou, et al., Phys. Rev. C 76, 034312 (2007) 6 Theoretical studies Relativistic mean-field model (RMF): Myaing Thi Win et al., Phys. Rev. C 78, 054311 (2008) Triaxial SHF with Skyrme-like YN interaction: Myaing Thi Win, et al., Phys. Rev. C 83, 014301 (2011) Antisymmetrized molecular dynamics (AMD): M. Isaka, et al., Phys. Rev. C 83, 044323 (2011) Triaxial RMF: Bing-Nan Lu (吕炳楠), Phys. Rev. C 84, 014328 (2011) 7 Why to study deformations of hypernuclei Many p-shell and sd-shell nuclei are deformed. For example, experimentally, 10B and 11C have large quadrupole moments. F. Ajzenberg-Selove, Nucl. Phys. A490, 1 (1988); A506, 1(1990). Also, 8Be is known to be strongly deformed due to its double-α structure. 8 Several models for deformed nuclei Alpha-model Projected shell model (PSM) Deformed Skyrme Hartree-Fock (DSHF) Relativistic mean-field model (RMF) Antisymmetrized molecular dynamics (AMD) 9 Microscopic hyperon-nucleon interaction for deformed hypernuclei Free YN interaction BHF cal. for YN: Nijmegen soft-core hyperon-nucleon potential NSC89 asymmetric NN: Argonne v18 nucleon-nucleon interaction matter Effective YN interaction DSHF MF cal. BY, Hypernuclear Structure 10 Extended DSHF including hyperon-nucleon interaction Total energy of a hypernucleus in extended DSHF where the energy density SHF Due to the YN force, 11 Energy density due to hyperons It can be constructed from BHF energy density, where the last term corresponds to the kinetic energy contribution of the Λ’s. The hyperon effective mass extracted from the BHF single-particle potential, 12 Parameterizations Finally, the energy density is written as The parameterizations of numerical results: 13 Extended SHF equation Minimizing the total energy of the hypernucleus, one arrives with extended SHF equation 14 Pairing interaction The pairing interaction is taken to be a density- dependent delta force Nucl. Phys. A551, 434 (1993) For light nuclei, Nucl. Phys. A722, c183, 2003 For medium-mass and heavy nuclei, Euro. Phys. J. A8, 59, 2000 15 Results Hypernuclei is deformed or not? Self-consistent DSHF calculations for experimentally studied hypernuclei including light, medium-mass and heavy hypernuclei. 16 Binding energies vs deformations 0.65 0.63 0.63 0.52 0.55 0.55 17 Binding energies vs deformations 18 X.-R. Zhou, et.al, PRC76, 034312(2007) Deformations, Energies, and B Λ 19 Binding energies vs deformations 20 X.-R. Zhou, H.-J. Schulze, et.al, PRC76, 034312(2007) Binding energies vs deformations 21 X.-R. Zhou, H.-J.Schulze, et.al, PRC76, 034312(2007) Shrinking effect of hyperons R b<r2> B(E2) ∝|<f| e r2 Y2 |i>|2 ∝R4 or (b<r2>)2 similar to Q-moment Motoba, Bando, Ikeda Prog.Theor.Phys. 70 (1983) 189. 4He + d + model ～20% shrinkage 22 The effect of hyperon in neutron-rich nuclei 23 X.-R. Zhou, H.-J. Schlze, et.al, PRC78, 054306 (2008) The Oxygen isotopes X.-R. Zhou, et.al, PRC78, 054306 (2008) exp. 24 Summary 1.The DSHF was extended to hypernuclei by including a microscopically derived hyperon- nucleon interaction. 2.The calculated core nuclei and the corresponding hypernuclei have similar deformations with the same sign when the core nuclei are well deformed. 3. The main qualitative effect of added hyperons is demonstrated: the nuclei close to the drip line are stabilized and new isotopes are potentially made available. 25 Prospect 1. Kaonic nuclei DSHF + Nucleon-kaon interaction 2. η nuclei？ DSHF + η-nucleon interaction 26 Cooperators H. Sagawa University of Aizu, Japan H.-J. Schulze, University of Catania, Italy En-Guang Zhao Institute of Theoretical Physics, CAS, China 27 Thank you! Welcome to Xiamen University, China! Furong Lake 28 Xiamen Univ.
Pages to are hidden for
"Zhou"Please download to view full document