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High Precision Hypernuclear Spectroscopy at JLab

High Precision Hypernuclear Spectroscopy at JLab. Liguang Tang Hampton University Content What we learned What we will do next. Lanzhou University and SNP2013, December, 2013. Introduction – Baryonic interactions.

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High Precision Hypernuclear Spectroscopy at JLab

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  1. High Precision Hypernuclear Spectroscopy at JLab Liguang Tang Hampton University Content What we learned What we will do next Lanzhou University and SNP2013, December, 2013

  2. Introduction – Baryonic interactions Understanding B-Binteractions is one of the essential tasks in Nuclear Physics: How the “world was built” H (1p) C(3 ) Astronomical Scale - Neutron Stars - He ( - 2p, 2n) • Hypernuclei: Study YN and YY interactions • A gateway to B-B interactions beyond YN and YY

  3. Introduction – Hypernuclei • A novel feature of -hypernuclei • Short range interactions •  coupling, NN 3-B forces • Change of core structures • Drip line limit • No Pauli blocking to  • Probe the nuclear interior • Baryonic property change or single particle nature of  in heavy baryonic system • Two-body effective -Nucleus potential for p-shell hypernuclei: VΛN(r) = Vc(r) + Vs(r) SΛSN + VΛ(r) LNSΛ + VN(r) LΛSN + VT(r) S12 The radial integral of Vi forms a unique set of parameters with which the N interactions can be fitted using a set of experimental results. • G-Matrix: Realistic N interactions LN

  4. Hypernuclear Experiments at JlabUsing ElectroproductionMechanisum +  - e e’  K- K+ K+  p n n   The (e, e’K+) Reaction ZA ZA ZA Z-1A ZA ZA The (K-, -) Reaction The (+, K+) Reaction • High momentum transfer (~300-400MeV/c) • Deeply bound, highest possible spin, both unnatural and natural parity states • Small production cross section but compensated by high beam intensity • Neutron rich hypernuclei and high iso-spin states (important to study - coupling) • Capable for high precision that is important for hypernuclear spectroscopy • Complimentary to spectroscopy produced by other mechanisms

  5. Hall C Program During CEBAF 6GeV Period PHASE I : (12B) Proved feasibility with 0.8 MeV resolution PHASE III (7He*, 10Be, 12B, 52V) Extend further in medium heavy mass region (~0.6 MeV FWHM) PHASE II: (7He, 12B, 28Al) High yield and better resolution (~0.6 MeV FWHM)  Lifetime of Heavy Hypernuclei

  6. 6 GeV Program (HKS) High Lights p(e, e’K+) and  using CH2 target Precise calibration of the kinematics coordinates and space Also involved in optimization of the reconstruction optics 2009, HKS-HES Jlab Hall C  M= 0.030.014 MeV/c2 M(-) = 76.9650.031 MeV/c2 

  7. Example: High Precision Spectroscopy of 12B 8 peaks identified; Energy resolution: 543 keV FWHM; Statistical significance(5) > 4.5 (smallest peak a) HKS 2009 R(1- :2-) 1:2.7 #1 c 624 20keV FWHM d b e #2 #3 a HKS: B(#1, g.s.) = 11.38 0.02(Stat.)  0.148(Sys.) MeV Emulsion: B(g.s.) = 11.37 0.06(Stat.)  0.04(Sys.) MeV

  8. 12Cvs12B: s Coupled to Low-Lying 11C or 11B Core States E(sys) =  0.09 13- #3 13- 6.050 6.0200.055 4th Doublet 23- 23- 3- 3- Low cross sections 3/2- 22- 3/2- 5.020 22- 5/2- 4.804 5/2- 4.445 4 4.319 6.266 12- 3.0830.050 12- 2.833 2.958 #2 0- 2nd Doublet 0- 1/2- 1/2- 2.125 2.000 3 2 1 3/2- 3/2- 0.1700.017 21- 21- 0.162 #1 1st Doublet 0 0 0 11- 0 11- 11B 12B [MeV] 12C [MeV] [MeV] 11C [MeV] Mass Spectroscopy by HKS  Spectroscopy by KEK-E566 JLab Hall C E05-115(2009) K. Hosomi et al. / Nuclear Physics A 914 (2013) 184–188 4th doublet separation: E(13- - 23-)  0.246  0.06(stat)  0.10(sys.) MeV Theory prediction: E(13- - 23-) = 0.107 (Millener)

  9. 12B: Spectroscopy in P-Shell States Theory (D.J. Millener) HKS Experiments Ex (MeV) State (Structure; J) Ex (MeV) Peak SD shell 11B Core S a 9.0090.077 11B(3/2-; gs)  P3/2; 2+ 10.48 b 10.2880.059 (40keV) 11B(3/2-; gs)  P; 1+ 10.52 11B(3/2-; gs)  P1/2; 2+ 10.98 (70keV) c 10.9840.030 11B(3/2-; gs)  P3/2; 3+ 11.05 d 11.7310.043 SD shell 11B Core S 11B(1/2-; 2.125)  P3/2; 2+ 12.95 e 12.5550.080 (100keV) 11B(1/2-; 2.125)  P; 1+ 13.05 SD shell 11B shell structure: S4P6(SD) Such unpredicted structures appear to be common in previously measured 12C and 12B spectrum

  10. Program High Lights – cont. (7He) - First observation of the 7He spectroscopy - • S. N. Nakamura et al., Phys. Rev. Lett. 110, 012502, (2013) A=7 isospin triplet (T=1) hypernuclei 7He g.s. (1/2+) #1 #2 #3 HKS 2009 JLab E05-115 4 times more statistics 2+ #3 #2 #1 E. Hiyama, et al., PRC53 2078 (1996)

  11. Program High Lights – cont. (10Be) Charge Symmetry Breaking Λ Λ n p α α α α 10Be 10B Λ Λ

  12. Program High Lights – cont. (10Be) 5 Doublets - Parity States (0ħ only) pΛ 3-/4- 4th 11.23 2-/3- 1st 2.53 3-/4- 3rd 6.48 1-/2-g.s. 0.0 0-/1- 2nd 3.22 Calculated by D.J. Millener

  13. Program High Lights – cont. (10Be) pΛ 3-/4- 4th 11.23 2-/3- 1st 2.53 3-/4- 3rd 6.48 1-/2-g.s. 0.0 0-/1- 2nd 3.22 • SD shell configuration mxing • Full 1ħ calculation needed • Positive parity core states

  14. KEK E140a SKS Program High Lights – cont. (28Al) JLab E01-011 28Si(e, e’K+)28Al (dΛ) HKS 2005 pΛ SΛ 28Si(p+,K+)28Si

  15. Program High Lights – cont. (28Al) JLab E01-011 28Si(e, e’K+)28Al (dΛ) HKS 2005 pΛ SΛ

  16. Importance of The Jlab Experiments • High precision spectroscopy of hypernuclear structure needed to improve understanding of the N interactions • Wide range of spectroscopy helping to investigate the property of the N interactions Goal of The Future Experiments • High precision • High yield • Wide range (elementary to the heaviest possible hypernuclei (A200) • Clean from background (at least below medium heavy) • Addition of new physics program – decay  spectrscopy

  17. Future Project: Super Hypernuclear Physics Experiment at JLab Enge () Unified collaboration from the previous Hall A and C collaborations HRS (e’) Septum Hampton is leading the collaboration in designing the future experiments HKS (K) HES () Septum HRS – HKS: (e, e’K+) experiments for mass spectroscopy HKS – Enge or HKS – HES: New decay -spectroscopy experiment

  18. Hypernuclei in wide mass range E89-009, E01-011, E05-115(Hall C) E94-107(Hall A) 1 20 50 200 1057 A Future mass spectroscopy (new proposal) H, 7Li, 9Be, 10B, 12C, 16O, 28Si, 52Cr Elementary Process Strangeness electro-production Neutron/Hyperonstar, Strangeness matter Hyperonization Softening of EOS ? Light Hypernuclei (s,p shell) Fine structure Baryon-baryon interaction in SU(3) LS coupling in large isospinhypernuclei Cluster structure Medium/heavyHypernuclei Single particle potential Distinguish ability of a  hyperon Uo(r), m*(r), VNN, …

  19. Study of Light Hypernuclei by Pionic Decay at JlabIllustration on the Main Features Comparison of Spectroscopic and Background - Production SPECTROSCOPY Light Hypernuclei to Be Investigated e e p * - K+ p  A1Z1 stop (b) Additions from 9Li and its continuum (Phase II: 9Be target) 6 3/2+ AZ 1/2+ Jp=? VS 1- A2Z2 7Li A(Z-1) A1(Z1+1) 8He 9Li 8Li 5 (Z-1) = Z1+Z2; A=A1+A2 6Li 1/2+ 7H 3B background 1-? 5/2+ 3/2+ 2- 4 BACKGROUND e Previously measured e Ex Ex Ex 0 0 0 1 1 1 * 3 Mirror pairs K+ Ex 0 2 - p(n) ,(-) N 2 AZ (A-1)Z’ 8Be 8B 9Li 8H 7He 6He 9B 8He 3H 6Li 10Be 10Li 10B 12B 9He 7Li 9Be 5H 4H 6H 8Li 7H 11Be 11B 1 A 2 6 7 11 12 8 1 5 3 4 9 10

  20. Illustration of Decay Pion Spectroscopy Additions from 12B and its continuum (Phase III: 12C target) (c) 1- 12B 9Be 10Be 8Be 9B 11B 10Li 9He 11Be 8H Jp=? 10B 5/2+ 3B background 8B (b) Additions from 9Li and its continuum (Phase II: 9Be target) 3/2+ 1/2+ 1- 7Li 8He 9Li 8Li 6Li 1/2+ 7H 3B background 1-? 5/2+ 3/2+ 2- Ex Ex Ex (a) 0 0 0 1 1 1 2-B decay from 7He and its continuum (Phase I: 7Li target) Ex 0 2 1-? 0+ 1/2+ 3H 6He 1/2+ 4H 7He 6H 3B background 3/2+ 5H 5/2+ Ex PMax PMin Ex 2 0 0 2 90.0 100.0 110.0 120.0 130.0 140.0 - Momentum (MeV/c)

  21. Physics Goal of Decay Pion Spectroscopy • Precise B (20keV) and high resolution (160keV FWHM) , spin-parity determination of g.s., charge symmetry breaking (CSB) from mirror pairs • Neutron rich light hypernuclei (- coupling) and neutron drip line limit (6H and 8H) • Formation of quasi free continuum and fragmentation mechanism This part of experiment is pending on our feasibility test result from MAMI-C. Two quick tests were in 2011 and 2012. New test will be done in Spring of 2014.

  22. Summary • JLabhypernuclear physics program is unique in the global Strange Nuclear Physics research • Existing results need to be published soon • It needs to continue in the 12 GeV period and new program needs to be solidly established with the best optimization

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