Physics of Exotic Nuclear Structure and Relativistic ...yitpschool2017/Meng-1.pdf · Mayer and...
Transcript of Physics of Exotic Nuclear Structure and Relativistic ...yitpschool2017/Meng-1.pdf · Mayer and...
Physics of Exotic Nuclear Structure and Relativistic Density Functional Theory
Jie MENG (孟 杰)
School of Physics,Peking University(北京大学物理学院)
Yukawa Institute for Theoretical Physics, Kyoto University(京都大学基礎物理学研究所)
Editorial Board: Science Bulletin (科学通报) SCIENTIA SINICA Physica, Mechanica & Astronomica(中国科学) Frontiers of Physics Chinese Physics Letters Progress in Physics (物理学进展)Chinese Physics C (before 2016)Nuclear Physics Review (核物理评论)WuLi (物理 in Chinese)
Managing Editor: International Journal of Modern Physics E
Opportunity with Facilities for Rare Isotope Beams
Exotic nucleus: nucleus @ extreme N/Z New isotopes:Limit of existence New phenomena:halo, shape, cluster…… New magic number New collective mode New radioactivity: proton, neutron, cluster…… Origin of element … … …
New opportunities in nuclear Physics
Facilities for Rare Isotope Beams
兰州HIRFL-CSR1997-2008年投资:2.93亿元
北京BRIF-II2014年
韩国 KoRIA 2012年开始建设投资:5.5亿美元
美国MSU-FRIB2008年开始建设
投资:5.5亿美元法国SPIRAL-II2006年开始建设
德国GSI-FAIR2007年开始建设投资:12亿欧元
日本RIKEN-RIBF2006年第一期完工
投资:550亿日元
惠州 HIAF2015年12月立项投资:15亿元
Existence Limit of nucleus
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82
8
20
28
50
8
2028
50
82
126
proton-rich nuclei
proton drip-line
neutron drip-line
neutron number (N)
neutron-rich nuclei
proton number (Z)
stable nuclei ~300 nucleiunstable nuclei observed ~2700 nucleidrip-lines (predictions) ~8000 nucleimagic numbers
~ 2200 nuclear masses were measured
New isotopes
New phenomena
New magic number
New collective mode
New radioactivity
Origin of element
Fundamental physics
Nuclear models
… … …
Opportunity with Facilities for Rare Isotope Beams
Exotic nucleus: nucleus @ extreme N/Z New isotopes:Limit of existence New phenomena:halo, shape, cluster…… New magic number New collective mode New radioactivity: proton, neutron, cluster…… Origin of element … … …
New opportunities in nuclear Physics
Nuclear Existence
Drip-lines in variant models
Figure: 10532 bound nuclei from Z=8 to Z=130 predicted by RCHB theory with PC-PK1. For 2227 nuclei with data, binding energy differences between data andcalculated results are shown in different color. The nucleon drip-lines predicted TMA,HFB-21, WS3, FRDM , UNEDF and without pairing correlation are plotted forcomparison.
The number of bound nuclides with between 2 and 120 protons is around 7,000 2 8 J U N E 2 0 1 2 | V O L 4 8 6 | N AT U R E | 5 0 9
See also: Afanasjev, Agbemava, Ray, Ring, PLB726(2013)680
arXiv:1704.08906
8 ⩽ Z ⩽ 120,9035 nuclei predicted to be bound
Possible isotopes made by FRIB
From Xue-Wei Xia
arXiv:1704.08906
Atomic Data and Nuclear Data Tables
T Baumann et al 2007 Nature 449 1022
Nuclear chart showing the most neutron-rich isotopes from C to Cl
Dripline(201712)
Opportunity with Facilities for Rare Isotope Beams
Exotic nucleus: nucleus @ extreme N/Z New isotopes:Limit of existence New phenomena:halo, shape, cluster…… New magic number New collective mode New radioactivity: proton, neutron, cluster…… Origin of element … … …
New opportunities in nuclear Physics
From Xin-Hui Wu
Halos, giant halos and deformed halos
Meng and Ring, Phys. Rev. Lett. 77(1996) 3963
Meng and Ring, Phys. Rev. Lett. 80(1998) 460
Zhou, Meng, Ring, Zhao , Phys.Rev.C82 (2010) 011301
Meng, Toki, Zhou, Zhang, Long &Geng, Prog. Part. Nucl. Phys. 57(2006) 470
Meng and Zhou, J. Phys. G: 42(2015) 093101
Shell structure, low density,continuum , bound state,spatial distribution, pairingcorrelation, coupling betweenbound state and continuum…
I. Tanihata, et al Phys. Rev. Lett. 55, 2676 (1985)
Nuclear Shape
By Bing-Nan Lu
Phys. Rev. Lett. 116, 032501 (2016)Phys. Rev. C 89, 011301(R) (2014)
Simple Nuclear Structure in cadmium @CERN
The simplicity of the linear increase isrevealed to be due to the pairing correlationwhich smears out the abrupt changesinduced by the single-particle shellstructure, and thus leads to a smooth shapeevolution
Multidimentionally constrained CDFT
Figure: Potential energy curve of 240Pu
• MDC-CDFT: all with even included• Triaxial & octupole shapes both crucial
around the outer barrier
1. Lu, Zhao, Zhou, PRC 85, 011301 (2012)2. Zhao, Lu, Zhao, Zhou, PRC 86, 057304 (2012)3. Lu, Zhao, Zhao, Zhou, PRC 89, 014323 (2014)4. Zhao, Lu, Vretenar, Zhao, Zhou, arXiv:1404.5466 (2014) Figure: 3D PES of 240Pu
courtesy of B.N. LUAbusara, Afanasjev, and Ring, PRC 85, 024314 (2012)
Nuclear Clustering
Evgeny Epelbaum et al, Phys. Rev. Lett. 106 (2011) 192501; Evgeny Epelbaum et al, Phys. Rev. Lett. 109 (2012) 252501
Hoyle State
An ab-initio calculation: Lattice EFT
Novel Clustering in exotic nuclei
Stabilization of a linear chain cluster
Zhao, Meng, Itagaki, Phys. Rev. Lett. 115, 022501(2015)
Neutron level
Spin-Isospin Effects
Novel Clustering in exotic nuclei
More experiments requires FRIB …
Opportunity with Facilities for Rare Isotope Beams
Exotic nucleus: nucleus @ extreme N/Z New isotopes:Limit of existence New phenomena:halo, shape, cluster…… New magic number New collective mode New radioactivity: proton, neutron, cluster…… Origin of element … … …
New opportunities in nuclear Physics
Evolution of the shell structure
From Dobaczewski
New Magic number 16
A. Ozawa, T. Kobayashi, T. Suzuki, K. Yoshida, and I. TanihataPhys. Rev. Lett. 84, 5493 (2000)
Evolution of the shell structure
The frontier: Calcium isotopes
New shell closures at N = 32 & 34?
The large and unexpected increase ofthe size of the neutron-rich calciumisotopes beyond N > 28 challenges thedoubly magic nature of 52Ca and opensnew intriguing questions on theevolution of nuclear sizes away fromstability.
R. F. Garcia Ruiz, et al
A Gade and B M Sherrill
Calcium isotopes in FRIB
FRIB provides access to key
neutron-rich Ca isotopes with
intensities sufficient to measure
crucial observables (masses, half-
lives, decay properties, excitations ).
It will be the only facility with 60Ca
yields above 0.01/s. FRIB will reach64Ca.
In-Beam γ -Ray Spectroscopy of 34,36,38Mg
P. Doornenbal, et al,Phys. Rev. Lett. 111(2013)212502
E(2) and E(4) energies for silicon (opentriangles) and magnesium (filled triangles)isotopes between N=20 and N=28. Thelower panel show the respective R(4/2)ratios
SM: Phys. Rev. C 60, 054315 (1999).3DAMP+GCM:Phys. Rev. C 83, 014308 (2011).
The emergence of a large area ofdeformation extending from N=20 toN=28 shell quenching.
Shell Quenching in Mg Isotopes
Opportunity with Facilities for Rare Isotope Beams
Exotic nucleus: nucleus @ extreme N/Z New isotopes:Limit of existence New phenomena:halo, shape, cluster…… New magic number New collective mode New radioactivity: proton, neutron, cluster…… Origin of element … … …
New opportunities in nuclear Physics
Novel excitation modes in atomic nucleus
A. Bohr & B. MottelsonInterpretation
vibration Rotation
Frauendorf & Meng, NPA 617 (1997) 131
Prediction
Chiral Rotation
Meng, Peng, Zhang, Zhou, PRC73 (2006) 037303
Prediction
Exploration of MχD in 78BrSpontaneous chiral and reflection symmetry breaking
H. Iwasaki, et al, Phys. Rev. Lett. 112, 142502 (2014) @ GRETINA
Doppler-shift lifetime measurement: the large collectivity for the 4 → 2 transitionrelative to that for 2 → 0 transition suggests a prolate character of the excitedstates, i.e., the onset of the oblate-prolate shape transition at low spin in 72Kr, presenting an extreme example of the shape transition in atomic nuclei.
Evolution of the Collectivity : Shape Transition
Opportunity with Facilities for Rare Isotope Beams
Exotic nucleus: nucleus @ extreme N/Z New isotopes:Limit of existence New phenomena:halo, shape, cluster…… New magic number New collective mode New radioactivity: proton, neutron, cluster…… Origin of element … … …
New opportunities in nuclear Physics
New Radioactivity
Proton emitter
Olsen et al., Phys. Rev. Lett. 110, 222501 (2013)Lim et al., Phys. Rev. C93, 014314 (2016)
Non-relativistic DFT Relativistic DFT
Landscape of Two-Proton Radioactivity
Proton radioactivity in relativistic continuum Hartree-Bogoliubov theory
Long Range Plan 2015
New Radioactivity
Neutron emitter
The experiments of two-neutron radioactivity in 26O and 28O willprovide crucial data for refining nuclear models at the limits ofnuclear existence.
Opportunity with Facilities for Rare Isotope Beams
Exotic nucleus: nucleus @ extreme N/Z New isotopes:Limit of existence New phenomena:halo, shape, cluster…… New magic number New collective mode New radioactivity: proton, neutron, cluster…… Origin of element … … …
New opportunities in nuclear Physics
Nuclear astrophysics
Quantity EffectSn neutron separation energy pathT1/2 -decay half-lives abundance pattern
timescalePn -delayed n-emission
branchingsfinal abundance pattern smooth r-abundance
G Nuclear Partition function abundance pattern (weakly)
fission (branchingsand products)
endpointabundance pattern?degree of fission cycling
NA<v> neutron capture rates final abundance pattern during freezeout ?
conditions for waiting point approximation
Isomeric states… Branch of the r-process pathfinal abundance patterntimescale
Nuclear physics input in the r-process
Relativistic Density Functional Theory
for nuclear structure and nuclear astrophysics
J. Meng (Editor)International Review of Nuclear Physics - Vol. 10 Relativistic Density Functional for Nuclear StructureWorld Scientific (2016)
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Brief History
Covariant Density Functional Theory
Numerical details
Nuclear ground state properties
Nuclear excited state properties
Interface with astrophysics and standard model
Summary & Perspectives
Relativistic Density Functional Theory
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Milestone toward the nuclear model
The discovery of neutron by Chadwickwhich verified the composition of nucleus asprotons and neutrons
The meson-exchange theory for theinteraction between nucleons by Yukawa
During the hundred years’ struggling, in the development of nuclear physics itself, there emerged a lot of significant milestones, including
H. Euler, Z. Physik 105, 553 (1937)Heisenberg's student who calculated the nuclear matter in 2nd order perturbation theory
Isospin and Z1/3-dependence of the nuclear charge radiiEur. Phys. J. A 13, 285–289 (2002).
31A 31A
Nuclear Bulk property
two-nucleon separation energy
∆S2p
much smaller after 8, 20, 28, 50, 82, 126
∆S2n
Nuclear Shell Model
原子核的许多性质呈现出随中子数或质子数而周期变化的现象
ARn + A-4Po TSudden rise at N = 126
Neutron capture cross section
Very small at N = 28, 50, 82, 126
Abrupt change in nuclear radius at N = 20, 28, 50, 82, 126
R = R(Z;N)-R(Z;N-2) 的实验值与液滴模型计算值之比
RRavg
RRavg
Nuclear Shell Model
Only smallest magic numbers are reproduced. Why ?
Spin-orbit term is necessary
Mayer and Jensen et al., 1949
srrV
rVV sso .)(1
M. G. Mayer, Phys. Rev. 75(1949)1969; 78(1950).O. Haxel, J. H. D. Jensen, and H. E. Suess, Phys. Rev. 75(1949)1766;Z. Phys. 128(1950)295;
Nuclear Shell Model
Thanks are due to Enrico Fermi for theremark, "Is there any indication of spin-orbitcoupling?" which was the origin of this paper.
Nuclear Shell Model
Nuclear Shell Model
Strong spin-orbit interaction
Great for:magic numbersground state propertiessome low lying excited states
Lead to deformed Nilsson model
S. G. Nilsson, Mat. Fys. Medd. Dan. Vid. Selsk. 29, No.16(1955).S. G. Nilssion, et al., Nucl. Phys. A131(1969) 1.
Shell model & Collective model
Totally fails for nuclear bulk properties
J. H. D. Jensen
M. G. Mayer E. P. Wigner
Nobel Prize in Physics 1963
Although the independent particleshell model could describe the single-particle motion in a nucleus with aphenomenological mean potential, itcannot provide even a qualitativedescription for the nuclear bulkproperties.
On the contrary, a unifiedphenomenological description ofnuclear vibration and rotation can beachieved by the collectiveHamiltonian whereas it is helpless inunderstanding the motion of a singlenucleon.
A. N. Bohr B. R. Mottelson J. Rainwater
Nobel Prize in Physics 1975
Shell model & Collective model
The independent particle shell model of nucleus by Mayer and Jensen etal., and the collective Hamiltonian for nuclear rotation and vibration byBohr and Mottelson, etc. However, since 1950s, nuclear physics steppedinto a more challenging stage.
0
10
20
30
40
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60
Ene
rgy
[MeV
]
0
10
20
30
40
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48.56MeV48.51MeV
Strutinsky Shell correction calculation
Compromise between Shell model and collective model
Great success for FRDMWS4 …
V.M. Strutinsky, Shell effects in nuclear masses and deformation energies, Nuclear Physics A 95 (1967) 420 Times Cited: 1,664 “Shells” in deformed nuclei, Nuclear Physics A 122 (1968) 1 Times Cited: 1,040
Weizsäcker-Skyrme (WS) formula “Isospin for S-O & E_sym + mirror nuclei”
inspired by the Skyrme energy-density functional and a macroscopic-
microscopic mass formula, with an rms deviation of 336 keV with respect to
the 2149 measured masses in 2003 Atomic Mass Evaluation.N. Wang, M. Liu and X. Z. Wu, Phys. Rev. C 81, 044322 (2010).
N. Wang, Z. Y. Liang, M. Liu and X. Z. Wu, Phys. Rev. C 82, 044304 (2010).M. Liu, N. Wang, Y. G. Deng, and X. Z. Wu, Phys. Rev. C 84, 014333 (2011).
Taking into account the surface diffuseness effect, the rms deviation with
2353 known masses falls to 298 keV.N. Wang, M. Liu, X. Z. Wu and J. Meng, Phys. Lett. B 734, 215 (2014).
Finite-Range Droplet Model (FRDM) P. Möller, J.R. Nix, W.D. Myers, W.J. Swiatecki, At. Data Nucl. Data Tables 59, 185 (1995). Times Cited: 2,385 Error of the mass model is 0.669 MeV
How to achieve microscopically and self-consistently a unified
description of the single-nucleon and collective motions of nucleus
based on the strong interaction theory is a crucial question to be
answered by nuclear scientists.
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The self-consistent mean-field approach to nuclear structure isanalogous to Kohn-Sham Density Functional Theory.
Density functional theory (DFT) , with the name comes from the use of functionals of the particle density, is aquantum mechanical theory used in physics and chemistry to investigate the structure (mainly the ground state) of many‐particle systems.
ji iiijii
i
rUVrUm
H )()(2
ˆ 22
Mean field potential Residual interaction
EVm
Hji
iji
i2
2
2ˆ
Many-body problems
10:03
• Bethe-Goldstone-Brueckner (1957):the effective interaction G within the nucleus is very weak
• Dürr-Teller (1956):relativistic single particle model:
• Fujita Miyazawa (1957): three-body force:
Hans Bethe Jeffrey Goldstone Keith Brueckner
Hans-Peter Dürr Edward Teller
Great ideas around 1950s Great ideas around 1950s