Neutron-Proton Asymmetry Dependence of Spectroscopic Factors

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1 Neutron-Proton Asymmetry Dependence of Spectroscopic Factors Jenny Lee The University of Hong Kong JCNP Symposium Nov 7-12, 2015

2 Hong Kong 惠州 Huizhou Beijing Shanghai Hong Kong Tokyo ~ 100 km HIAF University of Hong Kong First Nuclear Physics Group in 2014

3 International Workshop on Neutron-Proton Correlations & 12 th RIBF Discussion July 7-12, 2015 The University of Hong Kong

4 HKU Group Members Jenny Lee Zhengyu Xu (Postdoc) Ph.D. Univ. of Tokyo Xinxing Xu (Postdoc) Ph.D. CIAE Sylvain Leblond (Postdoc) Ph.D. Univ. of Caen External Members for Data Analysis Hongna Liu (PhD student, Peking Univ.) Yelei Sun (Research Assistant) Ph.D. Peking Univ. Jiajian Liu (PhD student) M.S. Shenzhen Univ. Taras Lokotko (PhD student) M.S. Univ. of Paris

Nuclear Experimental Programs @ HKU Correlation Effect on a Nucleon (Direct Reactions) One-nucleon knockout at 250 MeV/u (RIKEN, JL et al., paper in preparation) Knockout of 14 O at 60 MeV/u (RCNP, Y.

5 Nuclear Experimental HKU Correlation Effect on a Nucleon (Direct Reactions) One-nucleon knockout at 250 MeV/u (RIKEN, JL et al., paper in preparation) Knockout of 14 O at 60 MeV/u (RCNP, Y. Sun et al., paper in preparation) (p,d) Transfer of 34,46 Ar at 70 MeV/u (MSU, J. Manfredi, data in analysis) Neutron-Proton Correlations (Direct Reactions) Systematic np- & nn- transfer reactions on sd-shell nuclei (RCNP, Y. Ayyad et al., paper in prep Exclusive np-knockout of 12 C at 200 MeV/u (RIKEN, H. Liu et al., paper in preparation) (p,pnn) at GeV (IMP, Lanzhou, Proposal) Alpha-cluster Correlations (Direct Reactions) (p,p α) of neutron-rich Be (RIKEN, T. Lokotko PhD) Nuclear Structure (in-beam gamma spectroscopy) 30 Ne (RIKEN, H. Liu et al., paper in preparation) 53,55,56 Ca (RIKEN, J. Liu PhD) 77 Ni (RIKEN, Z. Xu et al., paper in preparation) 69,71,73 Co (RIKEN, T. Lokotko, data in analysis) 100 Sn (RIKEN, Proposal) Nuclear Structure (β-dacay spectroscopy) 173,174 Er (RIKEN, J. Liu in analysis) Detectors: DALI2 upgrade (60 NaI(Tl) detectors)

Nucleon Correlations Truncated shell model space + effective interactions Few active orbitals High Occupancy Inert Core In reality Short-range, tensor & collective correlations Inert Core Greater

6 Nucleon Correlations Truncated shell model space + effective interactions Few active orbitals High Occupancy Inert Core In reality Short-range, tensor & collective correlations Inert Core Greater distribution of nucleons to higher energy configuration Reduction in Occupancy Probing the nuclear wave function Removing nucleon from occupied orbital Cross sections (probability) depend on the single-particle occupancy & overlap of many-body wave functions

Spectroscopic Factor (SF) Cross Sections Reaction Model Spectroscopic Factors (expt) Quantify Occupancy Correlation Effects How much? What is the Isospin Dependence of nucleon correlations?

7 Spectroscopic Factor (SF) Cross Sections Reaction Model Spectroscopic Factors (expt) Quantify Occupancy Correlation Effects How much? What is the Isospin Dependence of nucleon correlations? How good the effective interaction in Shell Model can describe the correlations? SM description is accurate Some correlations missing in the interactions? (e,e p) Stable nuclei (near closed shell) Constant ~30-40% of SF reduction compared to theory Correlations missing in interactions used in SM L. Lapikas, Nucl. Phys. A553, 297c (1993) (e,e p) reactions Extend SF measurements to Exotic Nuclei!

8 SF(expt)/SF(theory) Isospin Dependence of Shell Occupancies? Q: Isospin Dependence? Knockout reactions: Yes & Strong A. Gade et al., Phys. Rev. Lett. 93, (2004) Phys. Rev. C 77, (2008) & reference therein Transfer reactions: Weak p( 34,36,46 Ar,d) at 33 A MeV J. Lee et al., Phys. Rev. Lett 104, (2010) Systematic difference between two probes! Incompatibility Incomplete understanding in underlying reaction mechanism Transfer Reaction NSCL: 34,46 Ar(p,d) at 70 A MeV - same energy as knockout reactions for direct comparison

Transfer Reactions for Correlation Studies 34, 46

Superconducting Cyclotron Laboratory Michigan

deuteron Completed in December 2014 (analyzed by

MCP θ Φ 33, 45 Ar To S800 Spectrograph P,E,Φ 1.

9 Transfer Reactions for Correlation Studies 34, 46 Ar + p d + 33, MeV/u National Superconducting Cyclotron Laboratory Michigan State University East Lansing, Michigan, USA deuteron Completed in December 2014 (analyzed by Juan Manfredi) CH 2 34,46 Ar Beam Primary Devices MCP θ Φ 33, 45 Ar To S800 Spectrograph P,E,Φ 1. High Resolution Array (HiRA) 2. S800 Spectrograph 3. Multi-Channel Plates (MCP)

10 SF(expt)/SF(theory) Isospin Dependence of Shell Occupancies? Q: Isospin Dependence? Knockout reactions: Yes & Strong A. Gade et al., Phys. Rev. Lett. 93, (2004) Phys. Rev. C 77, (2008) & reference therein Transfer reactions: Weak p( 34,36,46 Ar,d) at 33 A MeV J. Lee et al., Phys. Rev. Lett 104, (2010) Systematic difference between two probes! Incompatibility Incomplete understanding in underlying reaction mechanism Transfer Reaction NSCL 09084: 34,46 Ar(p,d) at 70 A MeV - same energy as knockout reactions for direct comparison Knockout Reaction?

SF(expt)/SF(theory) Knockout Reaction Mechanism Weakly-bound Deeply-bound Reaction Theory: Eikonal & Sudden Approximations R s =s exp /s theo Reactions ~ 70 MeV/u J. Tostevin et al., J. Phys. G, Part.

11 SF(expt)/SF(theory) Knockout Reaction Mechanism Weakly-bound Deeply-bound Reaction Theory: Eikonal & Sudden Approximations R s =s exp /s theo Reactions ~ 70 MeV/u J. Tostevin et al., J. Phys. G, Part. Phys. 25, 735 (1999) Target 9 Be or 12 C 14 O(d,t) Core Projectile (fast beam) ΔS=S n -S p (MeV) 1. Invariant with beam energy? NSCL, MSU - 14 O knockout at 60 MeV/u F. Flavigny et al., Phys. Rev. Lett. 108, (2012) Data at energies of MeV/A

One Nucleon Knockout Reaction on 30 Ne @ 230 MeV/u RIKEN H. Liu, J. Lee, P. Doornenbal, H. Scheit, S. Takeuchi, N. Aoi, K. Li, M. Matsushita1, D. Steppenbeck1, H. Wang, H. Baba, E. Ideguchi,, T.

12 One Nucleon Knockout Reaction on MeV/u RIKEN H. Liu, J. Lee, P. Doornenbal, H. Scheit, S. Takeuchi, N. Aoi, K. Li, M. Matsushita1, D. Steppenbeck1, H. Wang, H. Baba, E. Ideguchi,, T.Motobayashi, H. Sakurai, M. Takechi, Y. Togano Tokyo Tech. Y. Kondo, N. Kobayashi, T. Nakamura CNS/ Unvi. Of Tokyo S. Michimasa Theory Collaboration: RCNP/Osaka University K. Minomo, K, Ogata JAEA Y. Utsuno Hokkaido University M. Kimura Univ. of Surrey J. A. Tostevin, E.C. Simpson

1N-Knockout of nuclei with large ΔS at 230 AMeV 30 Ne: ΔS ~

1n-knockout : 30 Ne 29 Ne 1p-knockout : 30 Ne 29 F 12 C

54g/cm 2 DALI2 (γ-ray detection) 9 Be target (15mm) BigRIPS

13 1N-Knockout of nuclei with large ΔS at 230 AMeV 30 Ne: ΔS ~ 20 MeV 48 Ca beam 345MeV/u ~75pnA Beam: 30 ~ 230 A MeV 1n-knockout : 30 Ne 29 Ne 1p-knockout : 30 Ne 29 F 12 C target 2.54g/cm 2 DALI2 (γ-ray detection) 9 Be target (15mm) BigRIPS (Beam PID) 30 Ne 228MeV/u ~440 cps Purity: 63% ZDS: ZeroDegree Spectroscometer (fragment PID & momentum measurement)

14 γ detection Array - DALI2 S. Takeuchi et al., NIMA. 763, 596 (2014) Reaction Product Beam γ-ray Target 186 NaI(Tl) detectors θ coverage 11 to 165 E/E 11 % at 250 MeV/u 20 % FEP efficiency at 1MeV

15 Gamma Spectrum of 29 F & Cross Sections ZDS P. Doornenbel et al., paper in preparation SM: sd-pf model space with the SDPF-M effective interaction (Y. Utsuno) AMD: Antisymmetrized molecular dynamics with Gogny D1S interaction (M. Kimura) γ-energy threshold: 200 kev Inclusive σ: 5.8 (3) mb Ground-state σ: 5.2 (3) mb

Exponential background *Difference between fitting results with &

16 Gamma Spectrum of 29 Ne 12 C( 30 Ne, 29 Ne + γ) X ZDS C excitation 622(4) Counts/ 10keV Fit function: Response functions(geant4) + Exponential background *Difference between fitting results with & without C excitation Systematic error 232(6) NSCL Published in NNDC 931(8) 35 15

17 Gamma Spectrum & Cross Sections E level (kev) σ (mb) Inc. 62(2) < (4) (2) (2) (0.4)* * Lower limit γ-γ coincidence analysis: direct transition to g.s. γ-energy threshold: 200 kev H. Liu, JL et al., paper in preparation

51 (SM) and 0.36 (AMD) Assuming g.s. 3/2 - Rs = 0.59 (SM) and 0.39 (AMD) 29 F: g.s. σ: 5.2 (3) mb Rs=0.31 (SM) and 0.54 (AMD) M.

18 Comparison to Theoretical Cross Sections ERT: Eikonal reaction theory with an extension of the continuumdiscretized coupled-channels method (CDCC) K. Minomo, K. Ogata 29 Ne: σ (<200 kev) : 25 (4) mb P// 3/2 + : 14 mb, 3/2 - : 11 mb Assuming g.s. 3/2 + R s =σ exp /σ theo Rs = 0.51 (SM) and 0.36 (AMD) Assuming g.s. 3/2 - Rs = 0.59 (SM) and 0.39 (AMD) 29 F: g.s. σ: 5.2 (3) mb Rs=0.31 (SM) and 0.54 (AMD) M. Yahiro et al., Prog. Theor. Phys. 126, (2011), Prog. Theor. Exp. Phys. 2012, 01A206 (2012). K. Minomo et al., Phys. Rev. C 90, (2014)

19 30 Ne: ΔS ~ 20 MeV 12 C( 30 Ne, 29 Ne)X ~230 AMeV Weakly-bound Deeply-bound R s =s exp /s theo Assuming g.s. 3/ C( 30 Ne, 29 F)X ~230 AMeV Both SM & AMD over-predict g.s. SFs interactions need to be improved Large Reduction as data <90 AMeV Discrepancy not due to invalidity of reaction model at low-energy

Intranuclear Cascade Model (INC) ΔS=S n -S p (MeV) NSCL, MSU - 14 O knockout at 60 MeV/A F. Flavigny et al., Phys. Rev.

20 SF(expt)/SF(theory) Knockout Reaction Mechanism Weakly-bound Deeply-bound 2. Inert-core? R s =s exp /s theo Reactions ~ 70 MeV/u Direct KO Multiple scattering/ Evaporation Core excitation 14 O(d,t) Intranuclear Cascade Model (INC) ΔS=S n -S p (MeV) NSCL, MSU - 14 O knockout at 60 MeV/A F. Flavigny et al., Phys. Rev. Lett. 108, (2012) INC: Significant core-excitation process depletes the one-neutron removal channel Understanding the knockout reaction mechanism needed!

21 Studies of Single-Nucleon Correlations using Knockout Reactions Experiment at RCNP, Osaka University (Japan) RIKEN J. Lee, H. Liu, G. Lorusso, S. Nishimura, S. Takeuchi, J. Wu, Z. Xu Peking University Y. Ye, J. Chen, Y. Ge, Z. Li, J. Lou, R. Qiao, Y. Sun RCNP N. Aoi, Y. Ayyad, T. Hashimoto, E. Ideguchi, H.J. Ong, J. Tanaka, M. Tanaka, T. Trong, H. Suzuki, T. Yamamoto Y. Sun, J. Chen (PKU) Support (local + travel expense) by RCNP Young- Researcher Program + Supervision during 8-month / 3-month stay at RCNP

C 13 N + p 13 O + n 12 N + p 11 C + 2p Hodoscope K400 Ring Cyclotron pol p 400 MeV 3 He 140

22 Study of Reaction Mechanism Fully Exclusive Measurements of reaction products 大阪大学核物理研究中心 Osaka University Research Center for Nuclear Physics EN-Course Beam line Si Array 14 O + 12 C 13 N + p 13 O + n 12 N + p 11 C + 2p Hodoscope K400 Ring Cyclotron pol p 400 MeV 3 He 140 AMeV Light heavy ion 100 AMeV p RIKEN: Hodoscope K140 AVF Cyclotron Peking University: Si Array

23 Completed in Oct 2013 p RIKEN: Hodoscope Peking University: Si Array

24 Silicon Detection Array 32-strip double-sided silicon detector 1024 pixels 2 mm strip width excellent position resolution 4 CsI(Tl) crystals for total energy measurement Electronics (~500 Channels) PKU-made Preamplifier by Dr. Yucheng Ge RIKEN-made Preamplifier

25 Hodoscope and Tube Chamber T. Motobayashi & Rikkyo University group 42 Scintillators (1-meter long) 3 layers (active area of 1x1 m 2 ) E : 5 mm thick (13 bars) E1, E2: 60 mm thick Between Target to Hodoscope: 3.6 meters in vacuum Position & Energy resolution Hodoscope Acceptance: 0-7 Y. Sun, Ph.D Thesis 2015, paper in preparation

E-TOF S n = 23.2 MeV >1.5MeV 1 S n > 23.2 MeV >2.1MeV >2.

26 Knockout of 14 O on C target at 60 MeV/u Core-excitation Strength: σ( 14 O 13 O* to p-decay) Particle Identification in Hodoscope by ΔE-TOF and E-TOF S n = 23.2 MeV >1.5MeV 1 S n > 23.2 MeV >2.1MeV >2.5MeV 2 3 breakup in uniform phase space Coincidence Measurement of Residues and Decayed Protons

27 Invariant mass spectrum ( 13 O*) p + 12 N 13 O* 13 O* p+ 12 N g.s. σ< 2.0 (14) mb

28 Invariant mass spectrum ( 13 O*) 13 O* 11 C+p+p σ < 2.6(14) mb p + p+ 11 C 13 O* p + 11 C 12 N* p+p+ 11 C Triple-coincidence events p C 12 N* p C 12 N*

29 Knockout of 14 O on C target at 60 MeV/u 13 O* p+ 12 N g.s. σ< 2.0 (14) mb 13 O* 12 N* 11 C+p+p σ < 2.6(14) mb 11 C inclusive σ = 60(9) mb 14 O 13 O*, σ < 4.6(20) mb INC Calculation: σ 13 O (gs): 15.8 mb (while Eikonal model: 57.6 mb) σ 11 C: 66 mb, mainly from Core-excitation channels of 13 O Data: σ 13 O (gs): 13 mb σ 11 C: 60 (9) mb, but only 4.6 (20) mb from Core-excitation Y. Sun, JL et al., paper in preparation

30 Knockout of 14 O on C target at 60 MeV/u Large Asymmetry in Parallel Momentum Distribution 13 O NSCL, MSU - 14 O knockout at 60 MeV/u F. Flavigny et al., Phys. Rev. Lett. 108, (2012)

14 O(p,pN) at 100 MeV/u K. Ogata et al., Phys. Rev. C 92, 034616 (2015) Parallel Momentum Distribution DWIA Solid Hydrogen target Proposed by Y.

31 14 O(p,pN) at 100 MeV/u K. Ogata et al., Phys. Rev. C 92, (2015) Parallel Momentum Distribution DWIA Solid Hydrogen target Proposed by Y. Sun to RIKEN PAC-16 Investigate reaction mechanism Probe origin of reduction in SF & asymmetric P// Reaction model for reliable structure information 13 O, 13 N

32 Summary : Neutron-Proton Asymmetry Dependence of Spectroscopic Factors Single-nucleon Knockout of 30 Ne at 230 MeV/u (RIKEN) H. Liu et al., papers in preparation Large discrepancy not due to reaction energy being too low for Eikonal model description Knockout of 14 O on C target at 60 MeV/u (RCNP, Osaka University) Y. Sun et al. paper in preparation Reaction mechanism described by INC model is studied (p,pn) of 14 O at 100 MeV/u (RIKEN), DWIA Model Proposed by Y. Sun Weakly-bound Reactions ~ 70 MeV/u Deeply-bound 30 Ne

Study of Neutron-Proton Correlation & 3N-Force in 12 C

Study of Neutron-Proton Correlation & 3N-Force in C Outline: 1. Interesting physics on np-correlations in C 2. Probe: Two-nucleon knockout reaction Partial cross section and P // measurements 3. Experimental