Скачать презентацию ELI FAIR A Natural Pair Nuclear Structure Скачать презентацию ELI FAIR A Natural Pair Nuclear Structure

c55ccc79f115f81ac6140b37f1be58ea.ppt

  • Количество слайдов: 48

ELI & FAIR: A Natural Pair Nuclear Structure w. Photon Beams Norbert Pietralla, TU ELI & FAIR: A Natural Pair Nuclear Structure w. Photon Beams Norbert Pietralla, TU Darmstadt DAAD 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons DAAD BMBF

Outline § Nuclear physics with low-energy photons (nuclear dipole physics) § Impact of photon Outline § Nuclear physics with low-energy photons (nuclear dipole physics) § Impact of photon beams from Laser Compton Backscattering § Recent progress at Duke‘s HI S § Proof of Principle: 32 S § Pygmy Dipole Resonance: 138 Ba § Spin-Orbit Splitting: 40 Ar § Weak Coupling of Single Particles: 207 Pb § Parity Doublet : 20 Ne § Research potential of -ray beams from Laser Compton Backscattering § Summary 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons

Nuclear Physics with Me. V-range photon beams § Pure EM-interaction (nuclear-) model independent “small“ Nuclear Physics with Me. V-range photon beams § Pure EM-interaction (nuclear-) model independent “small“ cross sections, thick targets § Minimum projectile mass min. angular momentum transfer, spin-selective: dipole-modes § Polarisation „Parity Physics“ § Narrow Bandwidth (at ELI) „Selective Manipulation of Nuclear States“ 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons

Role of Isovector Spin-flip M 1 excitations in Nuclear Physics E (Me. V) Quark-Spin-flip Role of Isovector Spin-flip M 1 excitations in Nuclear Physics E (Me. V) Quark-Spin-flip Nucleon-Spin-flip 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons

Induced 3 N-Interaction in EFT Isovector M 1 excitation of 48 Ca § Vlow-k Induced 3 N-Interaction in EFT Isovector M 1 excitation of 48 Ca § Vlow-k interaction § 3 N-forces from EFT § SPEs self-consistently calculated in many-body perturbation theory S-DALINAC data J. Holt, A. Schwenk et al. , subm. to PRL 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons

Electric Giant Dipol Resonance (GDR) E 1 GDR in 197 Au GDR-Strength vs A Electric Giant Dipol Resonance (GDR) E 1 GDR in 197 Au GDR-Strength vs A Protons Neutrons Sensitive to average Proton-Neutron-Restoring Force but insensitive to shell structure: need low-energy E 1/M 1 data ! 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons Data from: A. Bohr, B. Mottelson “Nuclear Structure”

E 1 Strength Distribution Pygmy GDR Strength Quadrupol/ Oktupol 5 10 15 21. Oct. E 1 Strength Distribution Pygmy GDR Strength Quadrupol/ Oktupol 5 10 15 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons Energy/Me. V

Photonuclear Reactions Absorption Separation threshold ´ gs AX ´ A´Y Nuclear Resonance Fluorescence (NRF) Photonuclear Reactions Absorption Separation threshold ´ gs AX ´ A´Y Nuclear Resonance Fluorescence (NRF) Photoactivation Photodisintegration (-activation) 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons

Traditionally Bremsstrahlung: Kneissl, Pietralla, Zilges, J. Phys. G 32, R 217 (2006). 21. Oct. Traditionally Bremsstrahlung: Kneissl, Pietralla, Zilges, J. Phys. G 32, R 217 (2006). 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons

Scissors Mode of Deformed Nuclei (A. Richter, Darmstadt, 1983) Scissors mode classically: current loop Scissors Mode of Deformed Nuclei (A. Richter, Darmstadt, 1983) Scissors mode classically: current loop => M 1 magnetic dipole excitation electron scattering photon scattering Bohle et al. , NPA 458, 205 (1986). 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons

S-DALINAC at TU Darmstadt i 1 Source Electron Source 130 Me. V Electron LINAC S-DALINAC at TU Darmstadt i 1 Source Electron Source 130 Me. V Electron LINAC Photon Experiments 1 10 Me. V Injector: Photon Scattering / Photofission 2 < 30 Me. V Tagger: Photodesintegration / Photon Scattering 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons 2

Darmstadt Low-Energy Photon Scattering Site at S-DALINAC Ge(HP) Cu -detectors Cu < 10 Me. Darmstadt Low-Energy Photon Scattering Site at S-DALINAC Ge(HP) Cu -detectors Cu < 10 Me. V Target e- Electrons Energie Intensity Radiator target Bremsstrahlung E < 10 Me. V Energie 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons

21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons

Systematics of the Pygmy Dipole Resonance • Concentration around 5 -7 Me. V • Systematics of the Pygmy Dipole Resonance • Concentration around 5 -7 Me. V • Strong fragmentation • Summed strength: Scaling with N/Z ? Is this really all E 1 strength ? core skin A. Zilges et al. , PLB 542 (2002) 43. S. Volz et al. , NPA 779 (2006) 1. U. Kneissl et al. , J. Phys. G 32, R 217 (2006). 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons 15

Polarimetry with linearly polarized photon beams Scattering intensity distribution for linearly polarized photons 21. Polarimetry with linearly polarized photon beams Scattering intensity distribution for linearly polarized photons 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons

21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons

21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons

21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons

21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons

21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons

21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons

HI S Beam Profile; Parity of Pygmy Resonance HI S data 138 Ba Polarized HI S Beam Profile; Parity of Pygmy Resonance HI S data 138 Ba Polarized photon beam HI S 2002 Compton-polarimeter N. Pietralla et al. Phys. Rev. Lett. 88, 012502 (2002) EUROBALL Cluster 1999 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons

Proton Spin-Orbit Force near 40 Ca p-n are in different shells “Otsuka mechanism” 40 Proton Spin-Orbit Force near 40 Ca p-n are in different shells “Otsuka mechanism” 40 Ar HI S data 40 Ar T. C. Li, NP et al. Phys. Rev. C 73, 054306 (2006). 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons

21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons

Astrophysical Relevance of M 1 Data Langanke et al. , PRL (2004). Neutrino-cross sections Astrophysical Relevance of M 1 Data Langanke et al. , PRL (2004). Neutrino-cross sections Darmstadt data 54 Fe 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons

Collective Valence-Shell Structures Two-Phonon Structures • quadrupole-octupole • symmetric/mixed-symmetric 92 Zr 96 Mo C. Collective Valence-Shell Structures Two-Phonon Structures • quadrupole-octupole • symmetric/mixed-symmetric 92 Zr 96 Mo C. Fransen, NP et al. , Phys. Rev. C 70, 044317 (2004) 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons HI S data

21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons

Parity Physics Polarization in the entrance channel • Linear polarization (HI S) spin/parity programme Parity Physics Polarization in the entrance channel • Linear polarization (HI S) spin/parity programme (since 2001) • Circular polarization (HI S, S-DALINAC) parity non-conservation 20 Ne circular Forward-backward asymmetry ? target Parity-violation Weak interaction 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons -θ θ

20 Ne: Parity Mixing of Yrast States 21. Oct. 2011 | Norbert Pietralla @ 20 Ne: Parity Mixing of Yrast States 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons

20 Ne/28 Si in linearly/circularly polarized γ-beam 21. Oct. 2011 | Norbert Pietralla @ 20 Ne/28 Si in linearly/circularly polarized γ-beam 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons

20 Ne/28 Si in linearly/circularly polarized γ-beam 21. Oct. 2011 | Norbert Pietralla @ 20 Ne/28 Si in linearly/circularly polarized γ-beam 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons

Summary § Nuclear structure physics with -ray beams is a vivid field with high Summary § Nuclear structure physics with -ray beams is a vivid field with high discovery potential § ELI can become a major facility in this field § Needs: energy-tunable, high-flux, high-rep. rate, high-resolution, polarized -ray beam from LASER-Compton backscattering § All this will be possible at ELI ! § Future w. high Brightness: ELI & FAIR 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons

Thank you ! 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments Thank you ! 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons

21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons

Importance of the Proton-Neutron Interaction § Occupation-number dependence of spe‘s § Dominant origin for Importance of the Proton-Neutron Interaction § Occupation-number dependence of spe‘s § Dominant origin for shape-phase transition § Dominates evolution of collectivity and deformation ØStudy observables that are directly sensitive to the proton-neutron interaction in the valence shell ! 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons Rick Casten‘s Textbook Read it!

Scissors mode of deformed nuclei Darmstadt, 1983 Achim Richter (γ, γ‘) (e, e‘) Predicted Scissors mode of deformed nuclei Darmstadt, 1983 Achim Richter (γ, γ‘) (e, e‘) Predicted by Lo Iudice & Palumbo, 1978 @ 3 Me. V: Iachello, 1981 in IBM Bohle et al. , NPA 458, 205 (1986). 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons DALINAC data

94 Mo: the „hydrogen atom“ for MS structure M 1 as unique signature for 94 Mo: the „hydrogen atom“ for MS structure M 1 as unique signature for MS states 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons

Superconducting-DArmstadt LINear electron ACcelerator (S-DALINAC) § § 130 Me. V in-house electron linac TM Superconducting-DArmstadt LINear electron ACcelerator (S-DALINAC) § § 130 Me. V in-house electron linac TM 010 -mode acceleration „cw“ beam at 3 GHz („S“-band) Ideal for nuclear structure studies 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons Thanks to ü State of Hesse ü TU Darmstadt ü DFG

Electron and Proton Scattering on 94 Mo S-DALINAC data O. Burda et al. , Electron and Proton Scattering on 94 Mo S-DALINAC data O. Burda et al. , Phys. Rev. Lett. 99, 093502 (2007) § One-phonon states are strongly excited in (e, e‘) and (p, p‘) scattering experiments 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons

Conclusions Ex „GQR“ Valence shell 2+ p 2+ms 2+ Vmix n 2+ 1 § Conclusions Ex „GQR“ Valence shell 2+ p 2+ms 2+ Vmix n 2+ 1 § Understanding of transition densities requires configurations „beyond the valence shell“. § IBM (valence shell model) unable to predict behaviour of transition densities. § QPM serves here as „full theory“ (no effective charges, …). § IBM (valence shell model) can be considered „effective low-energy theory“ (effective interaction, effective charges, . . . ). § Effective models possible because of clear separation of scales (~2 Me. V vs. ~20 Me. V). 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons

Summary § Nuclear structure physics: exciting topic of quantum many-body physics § Theory developments: Summary § Nuclear structure physics: exciting topic of quantum many-body physics § Theory developments: from solid QCD to effective nuclear theory § Key-role of pn-interaction formation of collective structures § Proton-neutron mixed-symmetry states: sensitive to effective pninteraction in the valence shell § Isovector character of MSS first measured directly from transition radii § New signature for pn-mixed-symmetry states § First firm observation of mixed-symmetry state in radioactive isotope § Experimental methods available for research with „rare isotope beams“ § FAIR under construction § FAIR nuclear structure programme is starting right now (the students [and professors] can‘t wait…) 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons

Many Thanks… § P. von Brentano, J. Jolie, Ch. Fransen (Köln) § T. Ahn, Many Thanks… § P. von Brentano, J. Jolie, Ch. Fransen (Köln) § T. Ahn, L. Coquard, T. Möller, G. Rainovski, Ch. Walz, O. Burda, P. von-Neumann-Cosel, M. Danchev, C. Stoyanov, D. Tarpanov § J. Wambach, V. Yu. Ponomarev, R. V. Jolos § P. Reiter (Köln), V. Werner, R. F. Casten (Yale) § J. Gerl, J. Leske, P. Boutachkov, E. Merchan, N. Goel, M. Reese, Ch. Stahl § B. Alikhani, O. Möller, A. Heinz, Ph. John, A. Givechev, N. Kurz, H. Schaffner § Many more Ph. D/M. Sc. /B. Sc. -students for their enthusiasm DAAD 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons DAAD BMBF

Summary § Nuclear structure physics: exciting topic of quantum many-body physics § Theory developments: Summary § Nuclear structure physics: exciting topic of quantum many-body physics § Theory developments: from solid QCD to effective nuclear theory § Key-role of pn-interaction formation of collective structures § Proton-neutron mixed-symmetry states: sensitive to effective pninteraction in the valence shell § Isovector character of MSS first measured directly from transition radii § New signature for pn-mixed-symmetry states § First firm observation of mixed-symmetry state in radioactive isotope § Experimental methods available for research with „rare isotope beams“ § FAIR under construction § FAIR nuclear structure programme is starting right now (the students [and professors] can‘t wait…) 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons

Generic Aspects of Nuclear Structure: (and topic of this presentation) Heavy Atomic nucleus Two-fluid Generic Aspects of Nuclear Structure: (and topic of this presentation) Heavy Atomic nucleus Two-fluid quantum system • strongly coupled many-body system • COLLECTIVITY • consists of two equivalent entities (protons-neutrons) • ISOSPIN SYMMETRY • quantum system • SHELL STRUCTURE How do these features coexist, interplay, and compete? What are the dominant mechanisms and forces? 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons

21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons

Resolution Scale and Simple Pattern shell structure: interacting nucleons Cooper pairing: N s, d Resolution Scale and Simple Pattern shell structure: interacting nucleons Cooper pairing: N s, d boson system 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons Collective motion: nuclear shapes

Evidence for common structure of MSSs 21. Oct. 2011 | Norbert Pietralla @ Nu. Evidence for common structure of MSSs 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons

Isovector Giant Dipole Resonance (IVGDR) Strength of IVGDR vs A Protons Neutrons GDR in Isovector Giant Dipole Resonance (IVGDR) Strength of IVGDR vs A Protons Neutrons GDR in 197 Au § Sensitive to average pn-restoring force § However, insensitive to shell structure 21. Oct. 2011 | Norbert Pietralla @ Nu. STAR-week | Experiments with Real Photons