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Nuclear Structure’07: Exciting, Broad, RelevantWitold Nazarewicz (Tennessee)

• Introduction• Progress report• Connections• Relevance• Perspectives

Bordone, 1528

Schenk, Valk, 1700

Mercator, 1648

Introduction

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Nuclear science is entering a new era of discovery in understanding how nature works at the most basic level and in applying that knowledge in useful ways.

National Academy 2007 RISAC Report

Nuclear structure. A FRIB would offer a laboratory for exploring the limits of nuclear existence and identifying new phenomena, with the possibility that a more broadly applicable theory of nuclei will emerge. FRIB would investigate new forms of nuclear matter such as the large neutron excesses occurring in nuclei near the neutron drip line, thus offering the only laboratory access to matter made essentially of pure neutrons; a FRIB might lead to breakthroughs in the ability to fabricate the super-heavy elements with larger neutron numbers that are expected to exhibit unusual stability in spite of huge electrostatic repulsion.

Nuclear astrophysics. A FRIB would lead to a better understanding of key issues by creating exotic nuclei that, until now, have existed only in nature’s most spectacular explosion, the supernova. A FRIB would offer new glimpses into the origin of the elements, which are produced mostly in processes very far from nuclear stability and which are barely within reach of present facilities. A FRIB would also probe properties of nuclear matter important to theories of neutron-star crusts.

Weinberg’s Laws of Progress in Theoretical Physics

From: “Asymptotic Realms of Physics” (ed. by Guth, Huang, Jaffe, MIT Press, 1983)

Third Law: “You may use any degrees of freedom you like to describe a physical system, but if you use the wrong ones, you’ll be sorry!”

Nuclear Structure

Overarching goal:

– Self-bound, two-component quantum many-fermion system

– Complicated interaction based on QCD with at least two- and three-nucleon components

– We seek to describe the properties of finite and bulk nucleonic matter ranging from the deuteron to neutron stars and nuclear matter; including strange matter

– We want to be able to extrapolate to unknown regions

Theory of Nuclei

To arrive at a comprehensive and unified microscopic description of all nuclei and low-energy reactions from the the basic interactions between the constituent protons and neutrons

There is no “one size fits all” theory for nuclei, but all our theoretical approaches need to be linked. We are making great progress in this direction.

Questions and challenges

o How do protons and neutrons make stable nuclei and rare isotopes?

o What is the origin of simple patterns in complex nuclei? o What is the equation of state of matter made of nucleons? o What are the heaviest nuclei that can exist?

o When and how did the elements from iron to uranium originate? o How do stars explode? o What is the nature of neutron star matter?

o How can our knowledge of nuclei and our ability to produce them

benefit the humankind?– Life Sciences, Material Sciences, Nuclear Energy, Security

Physicsof nuclei

Nuclearastrophysics

Applicationsof nuclei

Questions that Drive the Field

Questions that Drive the Field

No shell closure for N=8 and 20 for drip-line nuclei; new shells at 14, 16, 32…

Phys. Rev. Lett. 99, 192501 (2007) Nature 449, 1022 (2007)

number of nuclei ~ number of processors!

Ab initio: GFMC, NCSM, CCM(nuclei, neutron droplets, nuclear matter)

GFMC: S. Pieper, ANL

1-2% calculations of A = 6 – 12 nuclear energies are possibleexcited states with the same quantum numbers computed

Quantum Monte Carlo (GFMC) 12C No-Core Shell Model 13C Coupled-Cluster Techniques

40Ca Faddeev-Yakubovsky Bloch-Horowitz …

Quantum Monte Carlo (GFMC) 12C No-Core Shell Model 13C Coupled-Cluster Techniques

40Ca Faddeev-Yakubovsky Bloch-Horowitz …

Input: •Excellent forces based on the phase shift analysis

•EFT based nonlocal chiral NN and NNN potentials

The nucleon-based description works to <0.5 fm

deuteron’s shape

Diagonalization Shell Model (CI)(medium-mass nuclei reached;dimensions 109!)

Honma, Otsuka et al., PRC69, 034335 (2004) and ENAM’04

Martinez-PinedoENAM’04

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A remark: physics of exotic nuclei is demanding

Interactions• Poorly-known spin-isospin

components come into play • Long isotopic chains crucialInteractions

Many-bodyCorrelations

OpenChannels

Open channels• Nuclei are open quantum systems• Exotic nuclei have low-energy decay

thresholds • Coupling to the continuum important

•Virtual scattering•Unbound states•Impact on in-medium Interactions

Configuration interaction• Mean-field concept often questionable• Asymmetry of proton and neutron

Fermi surfaces gives rise to new couplings

• New collective modes; polarization effects

S. Cwiok, P.H. Heenen, W. NazarewiczNature, 433, 705 (2005)

Large-scale Calculations

Stoitsov et al., PRL 98, 132502 (2007)

• Global DFT mass calculations: HFB mass formula: m~700keV• Taking advantage of high-performance computers

Prog. Part. Nucl. Phys. 59, 432 (2007)

The nucleus is a correlated open quantum many-body system

Environment: continuum of decay channels

€

0+

€

12C +α€

15N + p

€

15O+ n€

14N + d

€

0+

€

~ 0p( )12

€

~ 4 p− 4h( )

`Alignment’ of w.b. state with the decay channel

16O

Spectra and matter distribution modified by the proximity of scattering continuum

Thomas-Ehrmann effect

13C713N6

1943

2365

3502

1/2

3089

4946

3685

12C+n

12C+p

1/2

3/2

7162

6049

G. Hagen et al., nucl-th/0610072 P. Navratil et al., PRC 73, 065801 (2006)

K. Nollett et al., nucl-th/0612035

CCCC

NCSMNCSM

GFMCGFMC

GSMGSM

Connections

neutrons

protons

rp p

roce

ss

rp p

roce

ss

Crust

proces

ses

Crust

proces

sesn-Star

s-pro

cess

s-pro

cess

s-pro

cess

s-pro

cess

r processr processr processr process

stel

lar bu

rnin

g

stel

lar bu

rnin

gp pro

cess

p proces

s

p proces

s

p proces

s

How does the physics of nuclei impact the physical universe? • What is the origin of elements heavier than iron?• How do stars burn and explode?• What is the nucleonic structure of neutron stars?

Time (s)

X-ray burst

331

330

329

328

327

Fre

quen

cy (

Hz )

10 15 20

Nova

4U1728-34

T Pyxidis

KS 1731-260

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• Understanding the transition from microscopic to mesoscopic to macroscopic • Quantum Chaos and the Random Matrix Theory • Superconductivity• Loosely bound and open systems • Dynamical symmetries and Quantum Phase Transitions • Coulomb frustration• Fermionic sign problem

Connections to complex many-body systems

!

femto…femto…femto…femto…

Physicsof Nuclei

subfemto…subfemto…subfemto…subfemto… •Origin of NN interaction•Many-nucleon forces•Effective fields

nano…nano…nano…nano…

Quantum

many-body

physics

•In-medium interactions•Symmetry breaking•Collective dynamics•Phases and phase transitions•Chaos and order•Dynamical symmetries•Structural evolution

Giga…Giga…Giga…Giga…

NuclearAstrophysics

•Origin of the elements•Energy generation in stars•Stellar evolution•Cataclysmic stellar events•Neutron-rich nucleonic matter•Electroweak processes•Nuclear matter equation of state

• How does complexity emerge from simple constituents?

• How can complex systems display astonishing simplicities?

How do nuclei shape the physical universe?

Relevance

Medical Diagnostics and Therapy Radiography Computerized tomography Positron emission tomography MRI (regular) MRI (with polarized noble gases) Photon therapy Particle-beam therapies

Material Analysis Activation analysis Accelerator mass spectrometry Atom-trap trance analysis Forensic dosimetry Proton-induced x-ray emission Rutherfold backscattering Ion-induced secondary-ion emission Muon spin rotation

Safety and National Security Airport safety and security Large-scale x-ray scanners Nuclear materials detection Arms control and nonproliferation Stockpile stewardship Tritium production Space-radiation health effects Semi-conductor performance in radiation environments Food sterilization

Environmental Applications Climate-change monitoring Pollution control Groundwater monitoring Ocean-current monitoring Radioactive-waste burning

Energy Production and Exploration Nuclear reactors Oil-well logging R&D for next generation nuclear reactors Art and Archaeology Authentication Nuclear dating

Materials Te sting and Modification Trace-isotope analysis Ion implantation Surface modifications Flux-pinning in high-Tc superconductors Free-electron lasers Cold and ultra-cold neutrons Single-event efforts Microphone filters

Nuclear Science Applications

LRP’07 report

Each frame is a snapshot of the absorption of the polarized gas in the lung tissue during a normal respiration cycle. The 129Xe concentration is color coded with red indicating the highest concentration.

Atom Trap Trace Analysis: 81Kr dating

MRI of inhaled polarized129Xe by a human

•Advanced Fuel Cycles• neutron-reaction cross sections from eV to 10 MeV

• the full range of (n,f), (n,n’), (n,xn), (n) reactions• heavy transuranics, rare actinides, and some light elements

(iron, sulfur)• Quantified nuclear theory error bars• Cross sections input to core reactor simulations (via data

evaluation)• BETTER CROSS SECTIONS AFFECT both SAFETY and

COST of AFC reactors.

• Science Based Stockpile Stewardship• Radiochemical analysis from days of testing: inference on

device performance shows final products but not how they came to be.

• Typical example Yttrium charged particle out reaction. LESS THAN 10% of cross sections in region measured.

• Theory with quantifiable error bars is needed.

Relevance of Nuclear Theory… Addressing national needs

AFC workshop proceedings: www.sc.doe.gov/np/program/docs/AFC_Workshop_Report_FINAL.pdfThe Stewardship Science Academic Alliance program workshop: http://www.orau.gov/2007SSAAS/index.htm

These two examples point to the relevance of Nuclear Theory to OTHER programs of national interest. Quantifiable theory error bars is a key desire. Room for large-scale computing (SciDAC)

Perspectives

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2007 Long Range Plan Recommendations for Nuclear Science

1. We recommend completion of the 12 GeV Upgrade at Jefferson Lab. The Upgrade will enable new insights into the structure of the nucleon, the transition between the hadronic and quark/gluon descriptions of nuclei, and the nature of confinement.

2. We recommend construction of the Facility for Rare Isotope Beams, FRIB, a world-leading facility for the study of nuclear structure, reactions and astrophysics. Experiments with the new isotopes produced at FRIB will lead to a comprehensive description of nuclei, elucidate the origin of the elements in the cosmos, provide an understanding of matter in the crust of neutron stars, and establish the scientific foundation for innovative applications of nuclear science to society.

3. We recommend a targeted program of experiments to investigate neutrino properties and fundamental symmetries. These experiments aim to discover the nature of the neutrino, yet unseen violations of time-reversal symmetry, and other key ingredients of the new standard model of fundamental interactions. Construction of a Deep Underground Science and Engineering Laboratory is vital to US leadership in core aspects of this initiative.

4. The experiments at the Relativistic Heavy Ion Collider have discovered a new state of matter at extreme temperature and density—a quark-gluon plasma that exhibits unexpected, almost perfect liquid dynamical behavior. We recommend implementation of the RHIC II luminosity upgrade, together with detector improvements, to determine the properties of this new state of matter.

FRIB

GSI

RIKEN

TRIUMF NSCL GANILISOLDE

Existing majordedicated facilities

Future major facilities

HRIBF

Radioactive Ion Beam Facilities Worldwide

Experiment

RIBF

Radioactive Ion Beam Facilities Timeline

20002000 20052005 20102010 20152015 20202020

CARIBU@ATLAS

NSCL

HRIBF

FRIB

ISOLDE

ISAC-II

SPIRAL2

SIS FAIR

RARF

ISAC-I

In FlightISOLFission+Gas Stopping

Beam on target

SPIRAL

• Young talent• Focused effort• Large collaborations

• Data from terra incognita

• High-performance computing• Interaction with computer scientists

What is needed/essential?

unedf.org

Jaguar Cray XT4 at ORNLNo. 2 on Top500

• 11,706 processor nodes• Each compute/service node

contains 2.6 GHz dual-core AMD Opteron processor and 4 GB/8 GB of memory

• Peak performance of over 119 Teraflops

• 250 Teraflops after Dec.'07 upgrade

• 600 TB of scratch disk space

1Teraflop=1012 flops1peta=1015 flops (next 2-3 years)1exa=1018 flops (next 10 years)

Connections to computational science

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Example:Example: Large Scale Mass Table Calculations Large Scale Mass Table CalculationsScience scales with processors

The SkM* mass table contains 2525 even-even nucleiThe SkM* mass table contains 2525 even-even nuclei A single processor calculates each nucleus 3 times (prolate, oblate, spherical) and A single processor calculates each nucleus 3 times (prolate, oblate, spherical) and

records all nuclear characteristics and candidates for blocked calculations in the records all nuclear characteristics and candidates for blocked calculations in the neighborsneighbors

Using 2,525 processors - about 4 CPU hours (1 CPU hour/configuration)Using 2,525 processors - about 4 CPU hours (1 CPU hour/configuration)

The even-even calculations define 250,754 configurations in odd-A and odd-odd nuclei The even-even calculations define 250,754 configurations in odd-A and odd-odd nuclei assuming 0.5 MeV threshold for the blocking candidatesassuming 0.5 MeV threshold for the blocking candidates

Using 10,000 processors - about 24 CPU hoursUsing 10,000 processors - about 24 CPU hours

Even-Even NucleiEven-Even Nuclei

Jaguar@Jaguar@

Odd and odd-odd NucleiOdd and odd-odd Nuclei

M. Stoitsov, HFB+LN mass table, HFBTHO

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At the end of the run:2032 converge for up to 500 iterations 404 converge up to 1000 iterations 123 converge up to 2000 iterations 152 converge up to 6000 iterations 26 do not converge

A typical run for the whole even-even mass chart contains about 2731 different bound nuclear states which identify the ground states of 1527 even-even nuclei.

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0 10 20 30 40 50 60 70 80 90 10010-5

10-4

10-3

10-2

10-1

100

Linear mixing Broyden M=3 Broyden M=7

194Rn, HFB+LN, Nsh=20

Sly4 + mixed pairing

Broyden MixingE

rror

Number of iterations

A. Staszczak, J. Dobaczewski, W. Nazarewicz, in preparation

Bimodal fission in nuclear DFT

nucl-th/0612017

S. Umar and V. OberackerPhys. Rev. C 76, 014614 (2007)

TDHF descriptionof heavy ion fusion

Supernova Modeling

Blondin, Mezzacappa, Nature 445, 58 (2007)

Conclusions

• Exciting science; old paradigms revisited • Interdisciplinary (quantum many-body problem, cosmos,…)• Relevant to society (national security, energy, medicine…)

• Theory gives the mathematical formulation of our understanding and predictive ability

• Experiment provides insights and verification • New-generation computers provide unprecedented

opportunities

The study of nuclei makes the connection between the Standard Model, complex systems, and the cosmos

Guided by data on short-lived nuclei, we are embarking on a comprehensive study of all nuclei based on the most accurate knowledge of the strong inter-nucleon interaction, the most reliable theoretical approaches, and the massive use of the computer power available at this moment in time. The prospects look good.

Thank You

Thank You

Backup

Different deformabilitie

s!

Different deformabilitie

s!

Shell effects in metastable minima seem to be under control

P.H. Heenen et al., Phys. Rev. C57, 1719 (1998)

Important data needed to fixthe deformability of the NEDF:•absolute energies of SD states•absolute energies of HD states

Advantages:•large elongations•weak mixing with ND structures

Example: Surface Symmetry EnergyMicroscopic LDM and Droplet Model Coefficients: P.G. Reinhard et al. PRC 73, 014309 (2006)

Nuclear DFTGlobal properties, global calculations

* Global DFT mass calculations: HFB mass formula: m~700keV• Taking advantage of high-performance computers

M. Stoitsov et al.

S. Goriely et al., ENAM’04

Cold gases, BEC’s, neutron matter

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Connections to complex many-body systems

• Dilute Fermions with large/infinite scattering length [impact in nuclear, cold-atom physics, condensed matter and astrophysics (neutron star crust, cooling)] PRL 91, 050401 (2003) 172 citations

•EOS, pairing gap near unitarity predicted at T=0 and T>0 PRL 96, 090404 (2006) 43 citations•DFT description: PRA 74, 041602(R) (2006)

• EFT/RG treatment of cold atoms: cond-mat/0606069• Pairing in asymmetric Fermi gasses: PRL 97, 020402 (2006)• Coupled cluster theory, method of moments [impact in nuclear physics and quantum chemistry] PRL 92,

132501 (2004)• DMRG approach to nuclei and open quantum systems Rep. Prog. Phys. 67, 513 (2004)

•Description of weakly-bound and unbound states of many-Fermion systems PRL 97, 110603 (2006)• Shell model with random interactions [quantum chaos,quantum dots] PRL 93, 132503 (2004); PRB 72,

045318 (2005); PRB 74, 165333 (2006)• Quantum phase transitions in mesoscopic systems [impact in nuclear, cold-atom, molecular physics] PRL

92, 212501 (2004); NPA 757, 360 (2005)• Applications of SM and DFT to atomic physics: PRA66, 062505 (2002)• Pairing correlations in ultra-small metallic grains (studies of the static-to-dynamic crossover): RMP 76,

643 (2004)

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