Study of shell evolution around the doubly magic 208 Pb via a multinucleon transfer reaction with an unstable beam Jose Javier Valiente Dobón (LNL-INFN,

Slides:



Advertisements
Similar presentations
LoI Relativistic Coulomb M1 excitation of neutron-rich 85 Br N. Pietralla G. Rainovski J. Gerl D. Jenkins.
Advertisements

Invariant-mass spectroscopy of neutron halo nuclei Takashi Nakamura 中村隆司 Tokyo Institute of Technology 東京工業大学 中日 NP 06, Shanghai.
Spectroscopy at the Particle Threshold H. Lenske 1.
Shell model studies along the N~126 line Zsolt Podolyák.
CEA DSM Irfu Shell evolution towards 100 Sn Anna Corsi CEA Saclay/IRFU/SPhN.
Coulomb excitation with radioactive ion beams
Unstable vs. stable nuclei: neutron-rich and proton-rich systems
Γ spectroscopy of neutron-rich 95,96 Rb nuclei by the incomplete fusion reaction of 94 Kr on 7 Li Simone Bottoni University of Milan Mini Workshop 1°-
Testing shell model on nuclei
Proton Inelastic Scattering on Island-of-Inversion Nuclei Shin’ichiro Michimasa (CNS, Univ. of Tokyo) Phy. Rev. C 89, (2014)
Fragmentation of very neutron-rich projectiles around 132 Sn GSI experiment S294 Universidad de Santiago de Compostela, Spain Centre d’Etudes Nucleaires.
Multinucleon Transfer Reactions – a New Way to Exotic Nuclei? Sophie Heinz GSI Helmholtzzentrum and Justus-Liebig Universität Gießen Trento, May ,
Nucleon knockout reactions with heavy nuclei Edward Simpson University of Surrey Brighton PRESPEC Meeting 12 th January 2011.
Estimation of production rates and secondary beam intensities Martin Veselský, Janka Strišovská, Jozef Klimo Institute of Physics, Slovak Academy of Sciences,
Relativistic Coulomb excitation of nuclei near 100 Sn C.Fahlander, J. Eckman, M. Mineva, D. Rudolph, Dept. Phys., Lund University, Sweden M.G., A.Banu,
Review of PHYSICAL REVIEW C 70, (2004) Stability of the N=50 shell gap in the neutron-rich Rb, Br, Se and Ge isotones Y. H. Zhang, LNL, Italy David.
Proton and Two-Proton Decay of a High-Spin Isomer in 94 Ag Ernst ROECKL GSI Darmstadt and Warsaw University.
1 TCP06 Parksville 8/5/06 Electron capture branching ratios for the nuclear matrix elements in double-beta decay using TITAN ◆ Nuclear matrix elements.
1 undressing (to fiddle the decay probability) keV gamma E0, 0 + ->0 + e - conversion decay E x =509 keV, T 1/2 ~20 ns Fully stripping.
Neutron transfer reactions at large internuclear distances studied with the PRISMA spectrometer and the AGATA demonstrator.
1 In-Beam Observables Rauno Julin Department of Physics University of Jyväskylä JYFL Finland.
Mean-Field Description of Heavy Neutron-Rich Nuclei P. D. Stevenson University of Surrey NUSTAR Neutron-Rich Minischool Surrey, 2005.
Experimental evidence for closed nuclear shells Neutron Proton Deviations from Bethe-Weizsäcker mass formula: mass number A B/A (MeV per nucleon)
Evolution of Nuclear Structure with the Increase of Neutron Richness – Orbital Crossing in Potassium Isotopes W. Królas, R. Broda, B. Fornal, T. Pawłat,
abrasion ablation  σ f [cm 2 ] for projectile fragmentation + fission  luminosity [atoms cm -2 s -1 ]  70% transmission SIS – FRS  ε trans transmission.
1 Reaction Mechanisms with low energy RIBs: limits and perspectives Alessia Di Pietro INFN-Laboratori Nazionali del Sud.
Pygmy Dipole Resonance in 64Fe
Neutron-rich lead isotopes provide hints on the role of the effective three-body forces Jose Javier Valiente Dobón Laboratori Nazionali di Legnaro (INFN),
LLNL-PRES This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344.
Recent improvements in the GSI fission model
Some aspects of reaction mechanism study in collisions induced by Radioactive Beams Alessia Di Pietro.
Anomalous two-neutron transfer in neutron-rich Ni and Sn isotopes studied with continuum QRPA H.Shimoyama, M.Matsuo Niigata University 1 Dynamics and Correlations.
RNB Cortina d’Ampezzo, July 3th – 7th 2006 Elisa Rapisarda Università degli studi di Catania E.Rapisarda for the Diproton collaboration 18 *
Probed with radioactive beams at REX-ISOLDE Janne Pakarinen – on behalf of the IS494 collaboration – University of Jyväskylä ARIS 2014 Tokyo, Japan Shapes.
Coulomb excitation of neutron-rich 32,33 Mg nuclei with MINIBALL at HIE-ISOLDE P. Reiter 1, B. Siebeck 1, M. Seidlitz 1, A. Blazhev 1, K. Geibel 1, N.
H.Sakurai Univ. of Tokyo Spectroscopy on light exotic nuclei.
July 29-30, 2010, Dresden 1 Forbidden Beta Transitions in Neutrinoless Double Beta Decay Kazuo Muto Department of Physics, Tokyo Institute of Technology.
Beta decay around 64 Cr GANIL, March 25 th V 63 V 64 V 60 V 61 V 63 Cr 64 Cr 65 Cr 61 Cr 62 Cr 60 Cr 64 Mn 65 Mn 66 Mn 65 Fe 67 Fe 1) 2 + in 64.
Reaction studies with low-energy weakly-bound beams Alessia Di Pietro INFN-Laboratori Nazionali del Sud NN 2015Alessia Di Pietro,INFN-LNS.
The INFN Italy EXOTIC group Milano, Napoli, Padova, NIPNE Romania, Crakow Poland. Presented by C.Signorini Dept. of Physics and Astronomy Padova (Italy):
Fusion of light halo nuclei
(F.Cusanno, M.Iodice et al,Phys. Rev. Lett (2009). 670 keV FWHM  M. Iodice,F.Cusanno et al. Phys.Rev.Lett. 99, (2007) 12 C ( e,e’K )
Observation of new neutron-deficient multinucleon transfer reactions
1 BETA-DELAYED NEUTRON SPECTROSCOPY OF 51,52,53,(54) Ca A. Gottardo, R. Grzywacz, M. Madurga ISOLDE Workshop2015.
Jose Javier Valiente Dobón (INFN-LNL, Italy) Lifetime measurements around the doubly-magic 48 Ca nucleus.
Variational Multiparticle-Multihole Configuration Mixing Method with the D1S Gogny force INPC2007, Tokyo, 06/06/2007 Nathalie Pillet (CEA Bruyères-le-Châtel,
Time dependent GCM+GOA method applied to the fission process ESNT janvier / 316 H. Goutte, J.-F. Berger, D. Gogny CEA/DAM Ile de France.
The experimental evidence of t+t configuration for 6 He School of Physics, Peking University G.L.Zhang Y.L.Ye.
Decay scheme studies using radiochemical methods R. Tripathi, P. K. Pujari Radiochemistry Division A. K. Mohanty Nuclear Physics Division Bhabha Atomic.
E.Clément Novembre 2011 E.Clément-GANIL Onset of collectivity in neutron-rich Sr and Kr isotopes: Prompt spectroscopy after Coulomb excitation at REX-ISOLDE,
Spectroscopy studies around 78 Ni and beyond N=50 via transfer and Coulomb excitation reactions J. J. Valiente Dobón (INFN-LNL, Padova,Italy) A. Gadea.
Production mechanism of neutron-rich nuclei in 238 U+ 238 U at near-barrier energy Kai Zhao (China Institute of Atomic Energy) Collaborators: Zhuxia Li,
Search for direct evidence of tensor interaction in nuclei = high momentum component in nuclei = TERASHIMA Satoru 寺嶋 知 Depart. of Nuclear Science and Technology,
Lecture 4 1.The role of orientation angles of the colliding nuclei relative to the beam energy in fusion-fission and quasifission reactions. 2.The effect.
1 EUNPC2015Aug 30 - Sep 4, 2015 LIFETIME MEASUREMENTS TO STUDY THE NATURE OF EXCITED STATES BEYOND N=50 AGATA + GANIL Andrea Gottardo.
Few-Body Models of Light Nuclei The 8th APCTP-BLTP JINR Joint Workshop June 29 – July 4, 2014, Jeju, Korea S. N. Ershov.
Pairing Evidence for pairing, what is pairing, why pairing exists, consequences of pairing – pairing gap, quasi-particles, etc. For now, until we see what.
L. Acosta1, M. A. G. Álvarez2, M. V. Andrés2, C. Angulo3, M. J. G
EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH Proposal to the ISOLDE and Neutron Time-of-Flight Committee Effects of the neutron halo in 15C scattering at.
ISOLDE Workshop and Users Meeting 2017
Isospin Symmetry test on the semimagic 44Cr
PHL424: Shell model with residual interaction
Production of heavy neutron-rich nuclei around N=126 in multi-nucleon transfer (MNT) reactions Long ZHU (祝龙) Sino-French Institute of Nuclear Engineering.
Rare Isotope Spectroscopic INvestigation at GSI
Flerov Laboratory of Nuclear Reactions, JINR, Dubna, Russia
Flerov Laboratory of Nuclear Reactions, JINR, Dubna, Russia
New Transuranium Isotopes in Multinucleon Transfer Reactions
Rare Isotope Spectroscopic INvestigation at GSI
Rare Isotope Spectroscopic INvestigation at GSI
Presentation transcript:

Study of shell evolution around the doubly magic 208 Pb via a multinucleon transfer reaction with an unstable beam Jose Javier Valiente Dobón (LNL-INFN, Italy) Suzana Szilner (Ruder Boskovic Institute, Croatia)

The Z=82 and beyond N= Pb 212 Pb g 9/2 The region around 208 Pb has been very difficult to populate experimentally due to its large A and Z. We want to study the developmet of nuclear structure in the nuclei beyond N=126. More especifically: 212,214 Pb and 210 Hg. Proof of principle that multinucleon transfer reactions with RIB is efficient to populate neutron-rich heavy binary partners and represents a competitive method to fragmentation The region around 208 Pb has been very difficult to populate experimentally due to its large A and Z. We want to study the developmet of nuclear structure in the nuclei beyond N=126. More especifically: 212,214 Pb and 210 Hg. Proof of principle that multinucleon transfer reactions with RIB is efficient to populate neutron-rich heavy binary partners and represents a competitive method to fragmentation 210 Hg

Fragmentation: 212,214,216 Pb: 8 + isomer

expth.exp. Calculations with Antoine and Nathan codes and K-H interaction E.K. Warburton and B.A. Brown PRC43, 602 (1991). th. exp. 212 Pb 216 Pb 214 Pb Shell Model calculations Kuo-Herling νg 9/2 2 νg 9/2 3 i 11/2 1 B(E2: 8 +  6 + )

Exp. data g 9/2 (n-1) + ν shells above + core exc. g 9/2 (n-1) + ν shells above g 9/2 Standard eff. charges: e ν = 0.5, e π = 1.5 Standard eff. charges: e ν = 0.5, e π = 1.5 Effective 3-body interaction The explicit coupling to the core restores the conjugation symmetry Kahana Lee Scott (KLS) interaction S. Kahana, Scott, Lee Phys. Rev. 185 (1969). A. Abzouzi, E. Caurier, and A.P. Zuker, Phys. Rev. Lett. 66, 1134,(1991). M. Dufour and A.P. Zuker PRC (1996) A. Gottardo et al., PRL109, (2012) Two bodyThree body Usually neglected! One body

Bi-isomer in 210 Hg E3 (663keV) and E1 (20 keV) 10 6 suppression in the E1 A. Gottardo et al., PLB (submitted) Such a large drop of the 3- excitation in 210 Hg, if proven by more sophisticated and high statistics experiments, will be a real challenge for present theoretical models: ad augusta per angusta. Such a large drop of the 3- excitation in 210 Hg, if proven by more sophisticated and high statistics experiments, will be a real challenge for present theoretical models: ad augusta per angusta.

Fragmentation reactions of Xe isotopes at 1 A GeV on heavy targets Multinucleon transfer reactions (higher spins) In fragmentation reactions (fragment separator (FRS) of GSI) on heavy targets one gets strongly decreasing yields (of medium mass neutron rich isotopes), due to secondary processes Fragmentation vs. MNT Red: 136Xe+Pb (fragmentation) Blue 124Xe+Pb (fragmentation) Black: 82Se+238U (MNT - PRISMA) Red: 136Xe+Pb (fragmentation) Blue 124Xe+Pb (fragmentation) Black: 82Se+238U (MNT - PRISMA) D. Henzlova et al, PRC78(2008) ,76 Se 87,88 Se 76,77 Ge 82,83 Ge

proton stripping and neutron pick- up channels lead to neutron rich medium mass nuclei proton pick-up and neutron stripping channels lead to neutron rich heavy mass nuclei C.H.Dasso, G.Pollarolo, A.Winther, PRL73 (1994)1907 Neutron-rich radioactive beam Stable beam Multinucleon transfer reactions RIB

GRAZING calculations Distribution of Pb-like 76 Rb 87 Rb 94 Rb Semiclassical theory (Grazing) G.Pollarolo, A.Winther S. Szilner et al., PRC (2007)

Experimental details Beam of 94 Rb 5.5 MeV/u (HIE-ISOLDE) Current: at/μC (UCx) – pps at MINIBALL (transmission eff. 5%) 13 mg/cm Pb target MINIBALL 9-gap amplifier a 1.5 ms pulse width Trigger gamma-gamma Background substraction between pulses (W. Catford et al., NPA (1997)) Target Beam Grazing Target-like Grazing Beam-like LAB. MNT to populate 212,214 Pb and 210 Hg among others The beam will be stopped in a beam dump outside MINIBALL well shielded to avoid background in the HPGe detectors. Straggling and Rutherford scattering contribute to a singles gamma rate at the secular equilibrium up to around 1 kHz

Beam time request Considering a gamma eff. of 6.0% for MINIBALL An effective thickness of 4.0 mg/cm 2 of 208 Pb Due to secondary processes the yields can be reduced up to a factor of 5. Considering this scenario we request 9 days of beam time including 1 day for setup. Total 9 days Considering this scenario we request 9 days of beam time including 1 day for setup. Total 9 days

Collaboration

Straggling + Rutherford Let's say that at the secular equilibrium we have 0.1% of pps = pps x 2 (average gamma multiplicity) x (efficiency of 1 crystal) = 90 Hz. Therefore, this contribution is negligible to the germanium counting. For the Rutherford scattering, the upper limit of cross section for angles beyond 15 degrees (opening of the reaction chamber) is approximately, for the lowest possible energy at the exit of the target (to take the upper limit), is mb and this gives a counting rate in singles of around 1 KHz. This does not represent a problem. For the trigger, gamma-gamma, this contribution is negligible. 0.1%

Time background substraction

GRAZING

Optimum Q value and adiabatic cut- off function

Semiclassical theory (Grazing,CWKB) G.Pollarolo, A.Winther Langevin equations V.Zagrebaev, W.Greiner Time Dependent Hartree-Fock theory Yabana comparison with 58Ni+208Pb data, L.Corradi et al PRC66(2002) MNT: experiment vs. theory

Total cross sections for pure neutron pick-up channels in the 90Zr+208Pb reaction. Total cross sections for pure neutron pick-up (right panel) and one-proton stripping (left panel) channels in the 40Ca+96Zr reaction. The points are the experimental data and the histograms are the calculated by GRAZING code. S. Szilner et al, Phy. Rev. C 76, (2007) Survival probability against fission (Ps) for the heavy target-like fragments as a function of the number of transferred protons averaged over neutron numbers. Points and histograms are the experimental and theoretical GRAZING values, respectively. L. Corradi et al, PRC 66, (2002). MNT: experiment vs. theory

Fragmentation reactions of 238U at 1 A GeV on Be targets H.Alvarez-Pol et al, Phys.Rev.C82(2010)041602R In fragmentation reactions on light targets one could produce very neutron rich nuclei in the “northeast” region, with cross sections down to 100 pb

1 GeVA 238 U beam from UNILAC-SIS at 10 9 pps 206 Hg 210 Hg 209 Tl 213 Tl 212 Pb 218 Pb 215 Bi 219 Bi A/q Z Fragmentation reactions

The neutron 2g 9/2 shell has a dominant role for the 8 + isomeric state. 1i 11/2, 1j 15/2 and 3d 5/2 also play a role 210 Pb n = Pb n = Pb n = Pb n = Pb n = 10 2g 9/ i 11/ j 15/ d 5/ state wave functions: occupational numbers show quite pure wave functions The ground state wave functions are in general more fragmented, with the 1i 11/2 shell around % Occupational numbers Wave functions from Kuo-Herling

B(E2) calculated considering internal conversion coefficients, and a keV energy interval for unknown transitions. Reduced transition prob. B(E2) B(E2; 8+ -> 6+) A (Lead) e ν =0.8 Large discrepencies factor ~ Pb 212 Pb 214 Pb 216 Pb Isomer t 1/2 (μs)0.20 (2)6.0 (8)6.2 (3)0.40 (4) B(E2) e 2 fm 4 Exp.47(4)1.8(3) B(E2) e 2 fm 4 KH Upper limit 90 keV based on K α X rays intensity (K electrons bound ~88 keV) B(E2) ~ E γ -5 (1+α) -1 τ -1

The results are roughly independent of the interaction used: KH, CD-Bonn, etc. One possibility is the mixing of states 6 + with different seniorites, but requires too large change of the realistic interaction  Is not the case Seniority mixing with g 9/2 seniority isomers also for the first g 9/2 ( neutrons: 70 Ni - 76 Ni, protons: 92 Mo - 98 Cd) Origin of discrepancies

Seniority Mixing Calculations by P. Van Isacker ν=2 ν=4

The results are roughly independent of the interaction used: KH, CD-Bonn, Delta, Gaussian One possibility is the mixing of states 6 + with different seniorites, but requires too large change of the realistic interaction  Is not the case Seniority mixing with g 9/2 seniority isomers also for the first g 9/2 ( neutrons: 70 Ni - 76 Ni, protons: 92 Mo - 98 Cd) So ….. Need to introduce state-dependent effective charges? Caution when using renormalised interactions Origin of discrepancies

208 Pb is the core (Z=82, N=126). For neutron-rich Lead isotopes, the N=6 major shell is involved No shells beyond the magic numbers for neutrons 2g 9/2 1i 11/2 1j 15/2 3d 5/2 3d 3/2 4s 1/2 2g 7/ S.p. energies (MeV) Shells N=126 N=184 N=7 major shell Kuo-Herling interaction: Valence space E.K. Warburton and B.A. Brown PRC43, 602 (1991).

Theory of effective interactions

Realistic collective nuclear H

Unified view

Effective 3 body interactions Effective 3-body terms appear naturally in the renormalization process, but they are NOT included in shell-model codes (ANTOINE and NATHAN): Two-body operators (H) become effective 3-body operators One-body transition operators (B(E2)) become effective 2-body operators Two bodyThree body Usually neglected! One body

Effective three-body forces Z=82N=126 h 11/2 i 13/2 2f 7/2 2g 9/2 πν In a perturbative approach, the bare g 9/2 is «dressed» with p-h excitations from the 208 Pb core ν shells above N=126 π shells above Z=82 The only way to include in a standard shell-model calculation (ANTOINE, NATHAN) the effective 3-body force and 2-body operators is to diagonalize usign the dressed wave function. Expectation value of the Hamiltonian and of the transition operators is calculated directly between the dressed wave functions, thus also including the many-body terms otherwise neglected. By allowing relevant p-h excitations from the core to the g 9/2 shell to neutron shells above, we include the previuosly neglected terms quasi-SU3

Exp. data g 9/2 (n-1) + ν shells above + core exc. g 9/2 (n-1) + ν shells above g 9/2 Standard eff. charges: e ν = 0.5, e π = 1.5 Standard eff. charges: e ν = 0.5, e π = 1.5 Effective 3-body interaction: Results The explicit coupling to the core restores the conjugation symmetry Kahana Lee Scott (KLS) interaction S. Kahana, Scott, Lee Phys. Rev. 185 (1969). A. Abzouzi, E. Caurier, and A.P. Zuker, Phys. Rev. Lett. 66, 1134,(1991). M. Dufour and A.P. Zuker PRC (1996)