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STUDY of Light - Hypernuclei by Spectroscopy of Two Body Weak Decay Pions. Mesonic Decay inside Nucleus Free: p + - 2-B: A Z A (Z + 1) + -. Liguang Tang Department of Physics, Hampton University Jefferson National Laboratory (JLAB).
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STUDY of Light -Hypernucleiby Spectroscopy of Two Body Weak Decay Pions Mesonic Decay inside Nucleus Free: p + - 2-B: AZ A(Z + 1) + - • Liguang Tang • Department of Physics, Hampton University • Jefferson National Laboratory (JLAB) PR10-001 @ PAC35, January 25, 2010, JLAB
Electro-production of Hypernuclei and Hyperfragments from the Continuum e’ e e e’ * K+ * K+ Background p p A (A-1) A YA Quasi-free production(Continuum) Direct production of Hypernuclei e e e’ e’ * * K+ K+ A rich source of a variety of light hypernuclei for new findings and discoveries 2B decay pion is used as the tool N N p p Aa Y(Ab-1) A Y(A-1) (Aa-1) Ab Production of Hyperfragment (Continuum) Production of Hyperfragment (Continuum)
Decay Pion Spectroscopy for Studyof Light -Hypernuclei e’ K+ Example: Direct Production 12C Ground state doublet of 12B B and e p 12Bg.s. 2- ~150 keV 1- 0.0 - 12Cg.s. Weak mesonictwo body decay
Decay Pion Spectroscopy for Light and Exotic -Hypernuclei Fragmentation Process e’ K+ Access to variety of light and exotic hypernuclei, some of which cannot be produced or measured precisely by other means Example: 12C e p 12B* 4H - Weak mesonictwo body decay (~10-10s) Fragmentation (<10-16s) 4He
Examples from FINUDA 12C(K-stop, -)12C P 7Li(K-stop, -) 7Li 12C(p) 11B + p S 7Be spectroscopy from: 7Li 7Be +- Spin/parity: 1/2+ 11Cspectroscopy from: 11B 11C+- Spin/parity: 5/2+?
Decay Pion Spectroscopy for StudyLight -Hypernuclei • 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: 6H, 7H, and 8H • Medium modification of baryon property – B(M1) from lifetime of ground and low lying isomeric states of hypernuclei These are rich and the most fundamental but so far unobtainable information needed for building the correct models for YN and Y-Nucleus interactions
Top View of the Experimental Layout Figure 6. Schematic top view of the experimental configuration for the JLAB hypernuclear decay pion spectroscopy experiment (Hall A). To Hall Dump To a local photon dump 1.2 GeV/c K+ 22mg/cm2 HES 64mg/cm2 94 – 140 MeV/c - 2.3 GeV Hall Z-axis Ideal if HKS and HES move to Hall A
Hall A Experimental Layout Trigger II: HRS(K) – HRS(e’) - Spectroscopy Experiment HRS - Hadron K+ Septum e Lucite Č e’ - HRS - Electron Hodoscope Drift Chamber Trigger I: HRS(K) – Enge() - Decay Pion Experiment
Free of Q.F. Background Quasi-free p + - (all) Within the HES acceptances
Three-Body Decay Background Example: 4He 3He + p + - P Acceptance
Hypernuclei from a 7Li Target Two-Body decay – 6 possible hypernuclei Three-Body decay – Background
Hypernuclei from a 9Be Target Two-Body decay – 6 additional hypernuclei
Hypernuclei from a 12C Target Two-Body decay – 12 additional hypernuclei
Illustration of Decay Pion Spectroscopy Additions from 12B and its continuum (Phase III: 12C target) (c) 12B 1- 9Be 1/2+ 10Be 9B Jp=? 9He Light Hypernuclei to Be Investigated 8Be 11B 11Be 10Li Jp=? 10B 8H Jp=? Jp=? Jp=? 5/2+ Jp=? p Jp=? 3B background 8B Previously measured (b) Additions from 9Li and its continuum (Phase II: 9Be target) 6 3/2+ 1/2+ Jp=? 1- 7Li 8He Mirror pairs 9Li 8Li 5 6Li 1/2+ 7H 3B background 1-? 5/2+ 3/2+ 2- 4 Ex Ex Ex (a) 0 0 0 1 1 1 3 Ex 0 2 2-B decay from 7He and its continuum (Phase I: 7Li target) 1-? 0+ 1/2+ 3H 6He 1/2+ 2 6H 4H 7He 10B 9B 8Be 8B 9Be 3H 10Li 9Li 4H 8Li 8H 6H 7H 5H 6He 8He 9He 6Li 7Li 7He 12B 11B 1 10Be 11Be 3B background 3/2+ 5H 5/2+ A Ex HES PMax HESPMin Ex 2 6 7 11 12 8 1 5 3 4 9 10 2 0 0 2 90.0 100.0 110.0 120.0 130.0 140.0 - Momentum (MeV/c)
Proposal to JLAB PAC35 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, IstitutoNazionalediFisicaNucleare, Sezionedi 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, IstitutoNazionalediFisicaNucleare, Italy G.M. Urciuoli, IstitutoNazionalediFisicaNucleare, Sezionedi Roma1, Italy R. De Leo, L. Lagamba, S. Marrone, IstitutoNazionalediFisicaNucleare, Italy H.J.Schulze, IstitutoNazionalediFisicaNucleare, Italy J. Feng, Y. Fu, J. Zhou, S. Zhou, China Institute of Atomic Energy, ChinaY. Jiang, H. Lu, X. Yan, Y. Ye, P. Zhu, University of Science & Technology of China, China.
Summary • High quality and high intensity CW CEBAF beam at JLAB made possible for high precision hypernuclearprograms, among which the decay pion program is unique. • The decay pion spectroscopy program will provide precise and fundamental information needed to significantly improve our understanding on YN and Y-Nucleus interactions. • A test run in the 6GeV period is important for the development of this program for the 12GeV period. • Unlike the mass spectroscopy program, this program does not request precision and stability on beam energy.