1. Liguang Tang Department of Physics, Hampton University Jefferson National Laboratory (JLAB) Sphere/Core-to-Core meetings, September 4-6, 2010, Prague, Czech Republic

2. e e’ ** K+K+  p A (A-1) Quasi-free  production (Continuum) e e’ ** K+K+  p A Y (A-1) Production of Hyperfragment (Continuum) N e e’ ** K+K+  p AaAa (A a -1) Production of Hyperfragment (Continuum) AbAb N Y (A b -1) e e’ ** K+K+  p A YAYA Direct production of Hypernuclei Background A rich source of a variety of light hypernuclei for new findings and discoveries 2B decay pion is used as the tool

3. p e’ e 12 C K+K+  12  B g.s. 12 C g.s.  - Weak mesonic two body decay 1-1- 0.0 2-2- ~150 keV Ground state doublet of 12  B B  and  Direct Production Example:

4. p e’ e 12 C  12  B * K+K+ 4 He  - Weak mesonic two body decay (~10 -10 s) Access to variety of light and exotic hypernuclei, some of which cannot be produced or measured precisely by other means    4H4H Fragmentation (<10 -16 s) Fragmentation Process Example:

5.  High precision on ground state light hypernuclei  Resolution: ~130 keV FWHM; mass precision : < ± 30 keV  Precise  binding energy  Charge symmetry breaking  Linkage between structures of hypernuclei and nuclei  Determining ground state spin/parity  Search for Isomeric low lying states ( Isomerism )  Study the drip line limit on  -hypernuclei, such as heavy hyper-hydrogen: 6  H, 7  H, and 8  H  Medium modification of baryon property

6. e e’e’e’e’ Hodoscop e Lucite Č Drift Chamber ---- K+K+K+K+ HRS - Hadron HRS - Electron Septum Trigger I: HRS(K) – Enge(  ) - Decay Pion Experiment Trigger II: HRS(K) – HRS(e’) - Spectroscopy Experiment For the 2012 test run: Aim to the Be window of the H 2 O target

7. Quasi-free   p +  - (all) Within the HES acceptances

8. Example: 4  He  3 He + p +  - P  Acceptance

9. Breakup ModeQ value (MeV)  - Decay P  (MeV/c)Width (keV/c) FWHM 7  He- 7 Li +  - 114.61165 p + 6  H-23.503 (B  =5.1) 6 He +  - 133.47165 n + 6  He-3.409 6 Li +  - 108.39165 d + 5  H-23.011 (B  =4.1) 5 He +  - 133.42~900 * 3 H + 4  H-16.995 4 He +  - 132.95165 4 H + 3  H-26.981 3 He +  - 114.29165 Two-Body decay – 6 possible hypernuclei Breakup ModeQ value (MeV)  - Decay P  max (MeV/c) – cut off d + 5  H-23.011 (B  =4.1) 4 He + n +  - 139.27 * 2n + 5  He-3.567 4 He + p +  - 102.42 3n + 4  He-24.868 3 He + p +  - 103.15 Three-Body decay – Background

10. Breakup ModeQ value (MeV)  - Decay P  (MeV/c)Width (keV/c) FWHM 9  Li- 9 Be +  - 121.18165 p + 8  He-13.817 8 Li +  - 116.40165 n + 8  Li-3.756 8 Be +  - 124.12165 2p + 7  H-40.328 (B  =6.1) 7 He +  - 135.17~270 * d + 7  He-12.568 7 Li +  - 114.61165 § 2n + 7  Li-12.218 7 Be +  - 108.02165 3 He + 6  H-29.608 (B  =5.1) 6 He +  - 133.47165 § 3 H + 6  He-9.745 6 Li +  - 108.39165 § 3n + 6  Li-18.957 6 Be +  - 100.58~220 **  + 5  H -11.749 (B  =4.1) 5 He +  - 133.42~900 *§ n +  + 4  H -12.005 4 He +  - 132.95165 § 6 He + 3  H-18.183 3 He +  - 114.29165 § Two-Body decay – 6 additional hypernuclei

11. Breakup ModeQ value (MeV)  - Decay P  (MeV/c)Width (keV/c) FWHM 12  B- 12 C +  - 115.49165 p + 11  Be-12.280 (B  =10.5) 11 B +  - 109.66165 n + 11  B-12.765 11 C +  - 105.99165 2p + 10  Li-32.908 (B  =12.3) 10 Be +  - 119.78165 d + 10  Be-18.264 10 B +  - 104.31165 2n + 10  B-22.544 10 C +  - 95.84165 3p + 9  He-48.534 (B  =7.8) 9 Li +  - 117.83165 3 He + 9  Li-30.237 9 Be +  - 121.18165 § 3 H + 9  Be-16.072 9 B +  - 96.88165 * 3n + 9  B-41.713 9 C +  - 96.71165 4p + 8  H-68.937 (B  =7.1) 8 He +  - 137.15165 4 Li + 8  He-46.961 8 Li +  - 116.40165 §  + 8  Li -14.444 8 Be +  - 124.12165 § 4 H + 8  Be-37.659 8 B +  - 97.09165 4n + 8  B-56.317 (B  =6.7) 8 C +  - 97.21365 ** p + 4 Li + 7  H-73.473 (B  =6.1) 7 He +  - 135.17~270 *§ 5 Li + 7  He-26.436 7 Li +  - 114.61165 § 5 He + 7  Li-25.782 7 Be +  - 108.02165 § 6 Be + 6  H-48.317 (B  =5.1) 6 He +  - 133.47165 § 6 Li + 6  He-24.186 6 Li +  - 108.39165 § 6 He + 6  Li-27.663 6 Be +  - 100.58~220 **§ 7 Be + 5  H-44.499 (B  =4.1) 5 He +  - 133.42~900 *§ 2  + 4  H -22.693 4 He +  - 132.95165 § 9 Be + 3  H-27.244 3 He +  - 114.29165 § Two-Body decay – 12 additional hypernuclei

12. (a) 2-B decay from 7  He and its continuum (Phase I: 7 Li target) 1/2 + HES P Max HES P Min 0 2 ExEx ExEx 0 2 4H4H 0+0+ 7  He 1/2 + 3/2 + 5/2 + 3H3H 6  He 1- ?1- ? 6H6H 5H5H 90.010 0.0 11 0.0 12 0.0 13 0.0 14 0.0  - Momentum (MeV/c) 3B background (b) 3B background 2 0 ExEx 1 0 ExEx 1 0 ExEx 1 0 ExEx 2-2- 3/2 + 5/2 + 1/2 + 9  Li 8  He J p =? 1-1- 8  Li 7H7H 1/2 + 3/2 + 7  Li 1- ?1- ? 6  Li Additions from 9  Li and its continuum (Phase II: 9 Be target) (c) Additions from 12  B and its continuum (Phase III: 12 C target) 12  B 1-1- 11  Be 11  B 10  Li 10  Be 5/2 + J p =? 10  B J p =? 9  He J p =? 9  Be 1/2 + 9  B J p =? 8H8H 8  Be 8B8B 3B background J p =? Illustration of Decay Pion Spectroscopy A p 1 2 34 5 678 910 1112 1 2 3 4 5 6 3H3H 4H4H 5H5H 6H6H 7H7H 8H8H 6  He 7  He 8  He 9  He 6  Li 7  Li 8  Li 9  Li 10  Li 11  Be 9  Be 10  Be 8  Be 11  B 9B9B 10  B 8B8B 12  B Light Hypernuclei to Be Investigated Previously measured Mirror pairs

13. Study of Light Hypernuclei by Pionic Decay at JLab M. Christy, C. Keppel, M. Kohl, Liguang Tang ( spokesperson ), L. Yuan ( spokesperson ), L. Zhu, Hampton University, USA N. Grigoryan, S. Knyazyan, A. Margaryan ( spokesperson ), L. Parlakyan, S. Zhamkochyan, H. Vardanyan, Yerevan Physics Institute, Armenia O. Hashimoto, S.N. Nakamura ( spokesperson ), Tohoku University, Japan P. Baturin, W. Boeglin, P. Markowitz, J. Reinhold ( spokesperson ), Florida International University, USA P. Bosted, K. de Jager, R. Ent, H. Fenker, D. Gaskell, T. Horn, M. Jones, J. LeRose ( spokesperson ), G. Smith, W. Vulcan, S.A. Wood, JLAB, USA E. Cisbani, F. Cusanno, S. Frullani, F. Garibaldi ( spokesperson ), M.L. Magliozzi, Istituto Nazionale di Fisica Nucleare, Sezione di Roma, Italy Ed.V. Hungerford, Department of Physics, University of Houston, USA L. Majling, Nuclear Physics Institute, Academy of Sciences of the Czech Republic, Czech Republic B. Gibson, Los Alamos National Laboratory, USA T. Motoba, Laboratory of Physics, Osaka Electro-Comm. University, Japan B. Hu, J. Shen, W. Wang, X. Zhang, Y. Zhang, Nuclear Physics Institute, Lanzhou University, China D. Androic, M. Furic, T. Petkovic, T. Seva, University of Zagreb, Croatia A. Ahmidouch, S. Danagoulian, A. Gasparian, North Carolina A&T State University, USA G. Niculescu, I. Niculescu, James Madison University, USA M. Iodice, Istituto Nazionale di Fisica Nucleare, Italy G.M. Urciuoli, Istituto Nazionale di Fisica Nucleare, Sezione di Roma1, Italy R. De Leo, L. Lagamba, S. Marrone, Istituto Nazionale di Fisica Nucleare, Italy H.J.Schulze, Istituto Nazionale di Fisica Nucleare, Italy J. Feng, Y. Fu, J. Zhou, S. Zhou, China Institute of Atomic Energy, China Y. Jiang, H. Lu, X. Yan, Y. Ye, P. Zhu, University of Science & Technology of China, China. Current Status: - PAC35 approved it as we requested - Tentative schedule – Spring 2012

14.  High quality and high intensity CW CEBAF beam at JLAB made high precision hypernuclear programs possible  Electroproduced hypernuclei are neutron rich and have complementary features to those produced by mesonic beams. Together with J-PARC’s new programs, as well as those at other facilities around world, the hypernuclear physics will have great achievement in the next couple of decades  The mass spectroscopy program will continue beyond JLAB 12 GeV upgrade  The new decay pion spectroscopy program will start a new frontier

15. Figure 6. Schematic top view of the experimental configuration for the JLAB hypernuclear decay pion spectroscopy experiment (Hall A). Hall Z-axis To Hall Dump K+K+ -- 22mg/cm 2 64mg/cm 2 To a local photon dump HES 94 – 140 MeV/c 2.3 GeV 1.2 GeV/c Ideal if HKS and HES move to Hall A