Collective modes past present and future perspectives Muhsin

Collective modes: past, present and future perspectives Muhsin N. Harakeh KVI, Groningen; GANIL, Caen International Symposium on High-resolution Spectroscopy and Tensor interactions (HST 15) Osaka, Japan 16 -19 November 2015 Osaka, Japan; 16 -19 November 2015 1

L=0 L=1 ISGMR ISGDR M. Itoh L=3 L=2 ISGQR ISGOR Osaka, Japan; 16 -19 November 2015 2

Microscopic picture: GRs are coherent (1 p-1 h) excitations induced by single-particle operators Microscopic structure of ISGMR & ISGDR Transition operators: Constant Overtone 2ћω excitation Overtone Spurious c. o. m. motion 3ћω excitation (overtone of c. o. m. motion) Osaka, Japan; 16 -19 November 2015 3

IVGDR r. Y 1 DN = 1 E 1 (IVGDR) DN = 2 DN = 0 E 2 (ISGQR) & E 0 (ISGMR) ISGMR ISGQR r 2 Y 0 r 2 Y 2 Osaka, Japan; 16 -19 November 2015 4

Equation of state (EOS) of nuclear matter More complex than for infinite neutral liquids Neutrons and protons with different interactions Coulomb interaction of protons 1. Governs the collapse and explosion of giant stars (supernovae) 2. Governs formation of neutron stars (mass, radius, crust) 3. Governs collisions of heavy ions. 4. Important ingredient in the study of nuclear properties. Osaka, Japan; 16 -19 November 2015 5

For the equation of state of symmetric nuclear matter at saturation nuclear density: and one can derive the incompressibility of nuclear matter: E/A: binding energy per nucleon J. P. Blaizot, Phys. Rep. 64, 171 (1980) ρ : nuclear density ρ0 : nuclear density at saturation Osaka, Japan; 16 -19 November 2015 6

Isoscalar Excitation Modes of Nuclei Hydrodynamic models/Giant Resonances Coherent vibrations of nucleonic fluids in a nucleus. Compression modes: ISGMR, ISGDR In Constrained and Scaling Models: EISGMR = ћ E ISGDR = ћ KA m r 2 7 3 27 e. F 25 m r 2 KA + F is the Fermi energy and the nucleus incompressibility: KA = r 2(d 2(E/A)/dr 2) r =R 0 J. P. Blaizot, Phys. Rep. 64 (1980) 171 Osaka, Japan; 16 -19 November 2015 7

Giant resonances § § Macroscopic properties: Ex, G, %EWSR Isoscalar giant resonances; compression modes ISGMR, ISGDR Incompressibility, symmetry energy KA = Kvol + Ksurf A 1/3 + Ksym((N Z)/A)2+KCoul. Z 2 A 4/3 Osaka, Japan; 16 -19 November 2015 8

ISGQR, ISGMR 10. 9 Me. V KVI (1977) 208 Pb( , ) at E =120 Me. V 13. 9 Me. V Large instrumental background and nuclear continuum! M. N. Harakeh et al. , Phys. Rev. Lett. 38, 676 (1977) Osaka, Japan; 16 -19 November 2015 9

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ISGMR, ISGDR ISGQR, HEOR 100 % EWSR At Ex= 14. 5 Me. V Osaka, Japan; 16 -19 November 2015 11

Grand Raiden@ RCNP ( , ) at E ~ 400 & 200 Me. V at RCNP & KVI, respectively BBS@KVI Osaka, Japan; 16 -19 November 2015 12

ISGQR at 10. 9 Me. V ISGMR at 13. 9 Me. V Osaka, Japan; 16 -19 November 2015 13

Difference of spectra 0° a′ 3° 0° a′ 1. 5° a′ 3° Difference Osaka, Japan; 16 -19 November 2015 14

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Multipole decomposition analysis (MDA) a. ISGR (L<15)+ IVGDR (through Coulomb excitation) b. DWBA formalism; single folding transition potential Osaka, Japan; 16 -19 November 2015 16

Transition density § ISGMR Satchler, Nucl. Phys. A 472 (1987) 215 § ISGDR Harakeh & Dieperink, Phys. Rev. C 23 (1981) 2329 § Other modes Bohr-Mottelson (BM) model Osaka, Japan; 16 -19 November 2015 17

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Uchida et al. , Phys. Lett. B 557 (2003) 12 Phys. Rev. C 69 (2004) 051301 116 Sn ( , ) spectra at 386 Me. V ISGDR MDA results for L=0 and L=1 ISGMR ISGDR ISGMR Osaka, Japan; 16 -19 November 2015 19

In HF+RPA calculations, Nuclear matter E/A: binding energy per nucleon ρ : nuclear density ρ0 : nuclear density at saturation 208 Pb KA: incompressibility KA is obtained from excitation energy of ISGMR & ISGDR KA =0. 64 Knm- 3. 5 J. P. Blaizot, NPA 591, 435 (1995) Osaka, Japan; 16 -19 November 2015 20

From GMR data on 208 Pb and 90 Zr, K = 240 10 Me. V [ 20 Me. V] [See, e. g. , G. Colò et al. , Phys. Rev. C 70 (2004) 024307] This number is consistent with both ISGMR and ISGDR Data and with non-relativistic and relativistic calculations Osaka, Japan; 16 -19 November 2015 21

Isoscalar GMR strength distribution in Sn-isotopes obtained by Multipole Decomposition Analysis of singles spectra obtained in ASn( , ) measurements at incident energy 400 Me. V and angles from 0º to 9º T. Li et al. , Phys. Rev. Lett. 99, 162503 (2007) Osaka, Japan; 16 -19 November 2015 22

KA = Kvol + Ksurf A 1/3 + Ksym((N Z)/A)2+Kcoul Z 2 A 4/3 KA ~ Kvol (1 + c. A-1/3) + K ((N - Z)/A)2 + KCoul Z 2 A-4/3 KA - KCoul Z 2 A-4/3 ~ Kvol (1 + c. A-1/3) + K ((N - Z)/A)2 ~ Constant + K ((N - Z)/A)2 We use KCoul - 5. 2 Me. V (from Sagawa) (N - Z)/A 112 Sn – 124 Sn: 0. 107 – 0. 194 Osaka, Japan; 16 -19 November 2015 23

K 550 100 Me. V Osaka, Japan; 16 -19 November 2015 24

D. Patel et al. , Phys. Lett. B 718, 447 (2012) Osaka, Japan; 16 -19 November 2015 25

RPA [K = 240 Me. V]; RRPA FSUGold [K = 230 Me. V]; RMF (DD-ME 2) [K = 240 Me. V]; (QTBA) (T 5 Skyrme) [K = 202 Me. V] Osaka, Japan; 16 -19 November 2015 26

RRPA: FSUGold [K = 230 Me. V]; SLy 5 [K = 230 Me. V]; NL 3 [K = 271 Me. V] Osaka, Japan; 16 -19 November 2015 27

E. Khan, PRC 80, 011307(R) (2009) The Giant Monopole Resonances in Pb isotopes E. Khan, Phys. Rev. C 80, 057302 (2009). K = 230 K = 216 Mutually Enhanced Magicity (MEM)? Osaka, Japan; 16 -19 November 2015 28

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Conclusions! § There has been much progress in understanding ISGMR & ISGDR macroscopic properties Systematics: Ex, G, %EWSR Knm 240 Me. V K 500 Me. V § Sn and Cd nuclei are softer than 208 Pb and 90 Zr. Osaka, Japan; 16 -19 November 2015 30

Challenges with exotic beams • Inverse kinematics Ex = 0 Me. V Ex = 30 Me. V 56 Ni(α, α )56 Ni* α = Target 56 Ni = Projectile 2 o 4 o 6 o 8 o Ex = 20 Me. V • Intensity of exotic beams is very low ( 104 – 105 pps) • To get reasonable yields thick target is needed • Very low energy ( sub Me. V) recoil particle will not come out of the thick target Osaka, Japan; 16 -19 November 2015 31

Nuclear structure studies with reactions in inverse kinematics - Possible at FAIR, RIKEN, GANIL, FRIB (beam energies of 50 -100 Me. V/u are needed!) Approach at GSI-FAIR (EXL): Helium gas-jet target Measure the recoiling alphas ( , ) 4 He heavy projectile target recoiling heavy ejectile Inconvenience: difficulty to detect the lowenergy alphas Osaka, Japan; 16 -19 November 2015 32

Storage Ring Experimental storage ring at GSI Luminosity: 1026 – 1027 cm-2 s-1 EPJ Web of Conferences 66, 03093 (2014) Osaka, Japan; 16 -19 November 2015 33

Detection system @ FAIR EXL recoil prototype detector has been commissioned Osaka, Japan; 16 -19 November 2015 34

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Active target A gas detector where the target gas also acts as a detector Ø Good angular coverage Ø Effective target thickness can be increased without much loss of resolution Ø Detection of very low energy recoil particle is possible MAYA active-target detector at GANIL Osaka, Japan; 16 -19 November 2015 37

Basics of kinematics reconstruction inside MAYA 20 Si detectors 80 Cs. I detectors Beam 56 Ni 500 mbar 95% He and 5% CF 4 Timing information from Amplification wires Range → Energy (SRIM) R 2 d → R 3 d , θ 2 d → θ 3 d Osaka, Japan; 16 -19 November 2015 38

3 rd dimension from timing information of the anode wires Range Energy Osaka, Japan; 16 -19 November 2015 39

Kinematics plot D ata 56 Ni(α, α )56 Ni* Osaka, Japan; 16 -19 November 2015 40

r or c y ) Peak d e ect fitting method c ien c i Eff ( a t Da Osaka, Japan; 16 -19 November 2015 41

Participants ATOMKI M. Csatlós L. Csige J. Gulyás A. Krasznahorkay D. Sohler KVI A. M. van den Berg M. N. Harakeh M. Hunyadi (Atomki) M. A. de Huu H. J. Wörtche NDU RCNP U. Garg T. Li B. K. Nayak M. Hedden M. Koss D. Patel S. Zhu H. Akimune H. Fujimura M. Fujiwara K. Hara H. Hashimoto M. Itoh T. Murakami K. Nakanishi S. Okumura H. Sakaguchi H. Takeda M. Uchida Y. Yasuda M. Yosoi WWU C. Bäumer B. C. Junk S. Rakers Osaka, Japan; 16 -19 November 2015 42

E 605: ISGDR in 56 Ni EXL Collaboration Soumya Bagchi Marine Vandebrouck Juan Carlos Zamora M. Vandebrouck et al. , Phys. Rev. Lett. 113 (2014) 032504 M. Vandebrouck et al. , Phys. Rev. C 92 (2015) 024316 S. Bagchi et al. , Phys. Lett. B 751 (2015) 371 Osaka, Japan; 16 -19 November 2015 43

Thank you for your attention Osaka, Japan; 16 -19 November 2015 44 44

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Kt = -500 +125 Me. V 100 M. Centelles et al. , Phys. Rev. Lett. 102, 122502 (2009) Osaka, Japan; 16 -19 November 2015 46

10. 9 Me. V 11. 0 Me. V 13. 9 Me. V 14. 0 Me. V M. N. Harakeh et al. , Nucl. Phys. A 327, 373 (1979) Osaka, Japan; 16 -19 November 2015 47

S. Brandenburg et al. , Nucl. Phys. A 466 (1987) 29 Osaka, Japan; 16 -19 November 2015 48

S. Brandenburg et al. , Nucl. Phys. A 466 (1987) 29 Osaka, Japan; 16 -19 November 2015 49

S. Brandenburg et al. , Nucl. Phys. A 466 (1987) 29 Osaka, Japan; 16 -19 November 2015 50

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Excitation energy of 56 Ni Data (Not efficiency corrected) Data (Efficiency corrected) Osaka, Japan; 16 -19 November 2015 54

Peak fitting method Background shape fixed manually (Background 1) Final background (Po. L 4 + C) Osaka, Japan; 16 -19 November 2015 Total fit = 9 Gaussian Func. + Po. L 4 + C 55

E* = 8. 5 Me. V, L = 1 E* = 11. 5 Me. V, L = 2 E* = 14. 5 Me. V, L = 2 E* = 17. 5 Me. V, L = 1 E* = 19. 5 Me. V, L = 0 E* = 22. 5 Me. V, L = 1 E* = 25. 5 Me. V, L = 1 E* = 28. 5 Me. V, L = 1 E* = 33. 5 Me. V, L = 1 Background 2 θCM [deg] Osaka, Japan; 16 -19 November 2015 56