LRP2010 - WG3 LRP2010 - WG3 Nuclear structure and dynamicsNuclear structure and dynamics

Navin AlahariThomas AumannYorick BlumenfeldPeter ButlerHans FynboAndres GadeaWolfram KortenAdam MajGerda NeyensThomas NilssonRobert RothPatricia Roussel-ChomazChristoph ScheidenbergerAndrea VitturiDario Vretenar Convener: Rauno Julin

NuPECC Liaisons: Angela Bracco, Maria Borge

WG3

WG3 Members

Convener’s guideline:

Focus on the future ideas !

WG3

•Introduction

•Theoretical aspect

•Onset of complexity

•Shell structure and isospin degree of freedom

•Superheavy elements

•Collective properties

•Reaction dynamics

•Ground-state properties

•Facilities and instrumentation

•Recommendations

The main Chapters of the WG3 draft The main Chapters of the WG3 draft

WG3

Nuclear structure physics

• Probing of a rich variety of quantum phenomena … … and even more in the untouched 6000 nuclei

• Diverse field

• Need a diverse set of tools, both theoretical and experimental

Introduction

WG3

Key questions

How can we describe the rich variety of low-energy structure and reactions of nuclei in terms of the underlying fundamental interactions between individual particles?

How can we predict the evolution of nuclear collective and single-particle properties as functions of mass and isospin, angular momentum and temperature?

What are the relevant low-energy degrees of freedom that govern nuclear dynamics?

How do regular and simple patterns emerge in the structure of complex nuclei?

WG3

Introduction

Ab Initio methods

Shell model

Energy density functional methods

Symmetries in nuclei and phase transitions

Reactions

Toward a unified description of nuclear structure and reactions

WG3

Theoretical aspect

17Ne 20Ne 22Ne

Modern approaches in nuclear theory aim at an ab-initio understanding of nuclear structure and reactions. Realistic effective interactions emerge from chiral interactions with 2-and 3-body forces. Many-body methods have lead to a consistent microscopic description of light nuclei using nucleons as degrees of freedom. These yield shell structure, clusters, halos, resonances, capture and transfer reactions and scattering states in a unified picture. The obtained understanding can be tested by experiments, which probe excitation for instance spectra, electromagnetic and weak transitions, densities, form factors, spectroscopic amplitudes.

A recent example comes from isotope shift measurements of drip-line nuclei using collinear laser spectroscopy. Precise and model independent measurements of charge radii, magnetic and quadrupole moments provide important information of the wave functions.

Sudden changes in the charge radii along an isotopic change are related to changes in the nuclear structure. The neon isotopes provide a particular interesting example. The experimental charge radii are compared with microscopic structure calculations using the Fermionic Molecular Dynamics (FMD) approach. FMD uses a Gaussian wave-packet basis and allows to describe nuclei with halos and clustering. The two-proton separation energy in 17Ne is only 0.93 MeV and the structure is understood as an 15O core and two protons in s2 or d2 configurations. The large charge radius in 17Ne is caused by a large s2 component of about 40%. In 18Ne the charge radius is smaller due to a smaller s2

component in the wave function. In 19Ne and 20Ne the charge radii increase again due to clustering in the ground state wave function.

Densitiy distributions of dominant FMD configurations indicating an extended two-proton wave function in 17Ne and α-clustering in 20Ne.

THEORY and EXPERIMENT

BOX example:

WG3

Theoretical aspect

Linking nucleons with nuclei

Weakly bound and unbound states

Haloes, clusters and few-body correlations

WG3

Onset of complexity

(light nuclei)

Integral approach:The accelerator and separation facilities are parts of the experimental set-up. The target is a part of the detector system

Higher RIB intensities and next generation instrumentation are required to study weakly bound states and to explore

the drip-lines towards heavier elements.

The system with the highest N/Z ever produced is 7H. It was identified as a resonance in the 8He(12C,13N)7H reaction at 15 MeV/nucleon. The active target MAYA was employed to measure kinematical correlations of the reaction residues.

7H identification

WG3

Onset of complexity

Changing shell structure

Vanishing and new shell gaps in light nuclei

Proton-neutron symmetric nuclear matter and the proton drip-line

Limits of existence in proton-rich nuclei and the double magic 100Sn

Proton-neutron pairing and pairing at high isospin values

Shell structure and isospin degree of freedom

WG3

Collaps of the N = 28 shell closure in 42Si28

SPEG SISSI

Secondary beams

48Ca 44S

44S 42Si

Château de Crystal 2+ 0+ : 770 keV

0

1

2

3

4

17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

neutron number N

2+ e

ne

rgy

(M

eV

)

CaS

Si

Wide range of intense RIBs, high-efficiency separators and gamma-ray arrays needed to probe new shell structures

and isospin degree of freedomWG3

ALFA

Shell structure and isospin degree of freedom

New elements

Reaction dynamics

Spectroscopy

Masses and atomic structures

Fission times

Chemistry

Towards neutron rich SHE

WG3

Superheavy elements

High-intensity stable-ion beams, target developments and high-efficiency detectors

and separators are needed in the future SHE

research

Hot-fusion cross-sections

Taufe von Element 112, am 12. Juli 2010 um 10 Uhr Copernicium is a noble metal

1 pbarn

WG3

Superheavy elements

Collective response of nuclei

Evolution of nuclear collective properties with spin and temperature

Shape coexistence, phase transitions and dynamical symmetries

WG3

Collective properties

High-sensitivity gamma-ray spectrometers combined with various ancillary spectrometers and large variety of

RIB’s and stable-ion beams are vital for extending the studies ofcollective response and collective properties to exotic nuclei.

Return of collective rotation at ultrahigh spin

WG3

Collective properties

Fusion reactions

Direct and deep-inelastic reactions

Fission process

Quasi free scattering

WG3

Reaction dynamics

The striking observation of a strong quenching of the single-particle strength as a function of asymmetry of the neutron and proton separation energy

Quasi-free scattering

Knock-out reactions at high energies with RIB in inverse kinematics

Exotic RIBs up to high energies and innovative spectrometer systems for kinematically complete measurements are needed

WG3

Origin unclear ?

Reaction dynamics

Charge and matter radii, nuclear moments and spins

The future with laser spectroscopy methods at ISOL facilities

The future with spin-oriented radioactive beams at in-flight facilities

The future with relativistic radioactive beams

Nuclear masses

WG3

Ground-state properties

Hyperfine-structure and β -NMR measurement spin and magnetic moment the ground state of 31Mg

is an 2p-2h deformed intruder state

N =50

Mass measurements N = 50 gap survives

Very large variety of instruments and ion-beam manipulation methods needed..

Extreme RIBs are welcome.

WG3

Ground-state properties

Facilities and instrumentation Accelerator facilities

Present European facilities for nuclear structure and reaction studies

FP7 – ENSAR – IA – TNA Facilities

ALTO – Orsay SIB, (RIB)GANIL – Caen RIB, SIBGSI – Darmstadt RIB, SIBISOLDE – CERN RIBJYFL – Jyväskylä SIB, (RIB) KVI – Groningen SIBLNL – Legnaro SIBLNS – Catania SIB, (RIB)

RIB - Radioactive Ion BeamSIB - Stable Ion Beam

European small scale facilities for nuclear physics and/or applications

including SPIRIT – FP7 – IA – TNA Facilities ENSAR – IA – JRA - ENSAR Facilities

Facilities and instrumentation

Timelines for the RIB facilities

Accelerator facilities

RIB roadmap

Stable ion beams along the NuPECC-ECOS report

see the RecommendationsWG3

Facilities and instrumentation

Instrumentation

Identification and decay spectroscopy

High-sensitivity gamma-ray and electron detection

High-energy gamma-ray and charged particle calorimetry

Versatile instrumentation for nuclear reactions

Experiments at storage rings

Ground state properties: Traps and lasers

Technological challenges

All large instrumentation projects in today’s nuclear structure and reaction research are governed by a co-operation in R&D work between groups,

who often represent different subfields of the community

WG3

Facilities and instrumentation

AGATA

CALIFA

SAGE

GASPARD

PARIS

FAZIA NEDA

HYDE

Large number of new state-off-the-art gamma-ray and particle detector arrays ….

.. to be combined with other spectrometer systems WG3

Facilities and instrumentation

Radioactive Ion Beam (RIB) Facilities

The continued strongest support for the full completion and utilization of the international RIB facilities, NuSTAR@FAIR and SPIRAL2, in coherence with the ESFRI recommendations.

The strongest support for the full completion and utilization of HIE-ISOLDE, recently approved by CERN, and SPES, funded by INFN. These advanced ISOL facilities, together with SPIRAL2, will bridge the technological gap between present day facilities and EURISOL.

The realisation of EURISOL. This long-term goal is the highest priority of our community for a future major facility that offers unique physics opportunities. Accession to the ESFRI list, based on the extensive Design Study for EURISOL carried out during the last decade, should be promoted in the near future.

WG3

Recommendations

Stable-ion beam facilities

Very strong support for existing and future stable-ion beam facilities.

High-intensity stable-ion beams up to 100 pµA for studies of extremely weakly produced nuclei such as super-heavy elements. Installation of the high-intensity LINAG within the SPIRAL2 project and a dedicated cw-linac as proposed at GSI (NuSTAR-FAIR).

Large variety stable-ion beams up to 100 pnA for in-beam studies, where the beam intensity is limited by the detector counting rates (JYFL, LNL and LNS).

Other stable-ion beam facilities are needed for specific experiments, instrument development and testing, to reach large user communities and to allow for the education of next-generation researchers (TNA- and EWIRA- facilities of EU-FP7-IA-ENSAR)

The long-term goal for a new dedicated high-intensity stable ion beam facility in Europe is recommended as an important future project.

Role of ECOS network will be important.

WG3

Recommendations

AGATA

Very strong support for the swift realisation of the AGATA spectrometer

AGATA 1/12 demonstrator now in operation at LNL

The completion of the 1/3 of AGATA by 2013 and the realisation of the full AGATA spectrometer is importance for the successful exploitation of present and future radioactive and stable-ion beam facilities.

WG3

Recommendations

Theory Initiative

Integrating theory into the European nuclear physics infrastructure

The large infrastructures should invest more into theory projects

Funding of project-oriented, medium- and long-term theoretical initiatives at universities and laboratories.

New permanent coordinating structure for advanced training at the European level needs to be implemented, either at ECT* or through new initiatives.

Supporting ECT* Trento in its leading role as a training centre for young researchers, and an international venue for scientific meetings that involve both theorists and experimentalists.

USAUniversal Nuclear Energy Density Functional UNEDF 15 institutions

$15M / 5 years

Model project:

WG3

Recommendations

Thank you for your attention

WG3