210 likes | 291 Vues
E05-115: Third Generation Hypernuclear Experiment. E05-115 : Spectroscopic investigation of L hypernuclei in the wide mass region using the (e,e’K + ) reaction. Hall C User Meeting January 18th, 2008 (Fri) Yu Fujii Tohoku Univ. JLab E05–115 collaborators in proposal
E N D
E05-115: Third Generation Hypernuclear Experiment E05-115 : Spectroscopic investigation of L hypernuclei in the wide mass region using the (e,e’K+) reaction Hall C User Meeting January 18th, 2008 (Fri) Yu Fujii Tohoku Univ.
JLab E05–115 collaborators in proposal ~ 87 researchers from 19 institiutes Dept. of Phys. Tohoku Univ. Y. Fujii, O. Hashimoto, H. Kanda, M. Kaneta, D. Kawama, K. Maeda, N. Maruyama, A. Matsumura, S.N. Nakamura, K. Nonaka, Y. Okayasu, M. Sumihama, H. Tamura, K. Tsukada, Y. Miyagi Dept. of Phys. Hampton Univ. O.K. Baker, L. Cole, M. Christy, P. Gueye, C. Jayalath, C. Keppel, S. Malace, E.K. Segbefia, L. Tang, V. Tvaskis, L. Yuan Dept. of Phys. Florida International Univ. A.Acha, W. Boeglin, L. Kramer, P. Markowitz, N. Perez, B. Raue, J. Reinhold, R. Rivera Dept. of Phys. Yamagata Univ. S. Kato Institute of Particle and Nuclear Physics (KEK) H. Noumi, Y. Sato, T. Takahashi Laboratory of Phys, Osaka Electro-Comm. Univ. T. Motoba Dept. of Phys. Univ. of Houston Ed. V. Hungerford, K.J. Lan, Y. Li, N. Elhayari, S. Randeniya, N. Klantrains Thomas Jefferson National Accelerator Facility P. Bosted, R. Carlini, V. Dharmawardane, R. Ent, H. Fenker, D. Gaskell, M. Jones, D. Mack, J. Roche, G. Smith, W. Vulcan, S. Wood, C. Yan Yerevan Physics Institute R. Asaturyan, H. Mkrtchyan, A. Margaryan, S. Stepanyan, V. Tadevosyan Nuclear Physics InstituteLanzhou Univ. X. Chen, B. Hu, S. Hu, Y. Song, W. Luo, B. Wang Dept. of Physics / Applied Phys. Univ. of Zagreb D. Androic, M. Furic, T. Petkovic, M. Planinic, T. Seva Dept. of Phys. North Carolina A&T State Univ. A. Ahmidouch, S. Danagoulian, A. Gasparian Dept. of Phys. Louisiana Tech Univ. N. Simicevic, S. Wells Dept. of Phys. James Madison Univ. G. Niculescu, M.-I. Niculescu Dept. of Phys. Univ. of North Carolina at Wilmington L. Gan Dept. of Phys. Duke Univ. M.W. Ahmed Dept. of Phys. Univ. of Maryland F. Benmokhtar, T. Horn Dept. of Phys. Southern Univ. at New Orleans M. Elaasar Phys. and Astro. Dept. California State Univ. Ed F. Gibson
Introduction E05-115 : Λ Hypernuclear Spectroscopy in the wide mass region • p-shell nuclei :6,7Li, 10,11B, 12C, (H2O for calibration) • ~ Fine structure ; core excited states etc. • Baryon-baryon interaction in SU(3), • charge symmetry breaking, • LS coupling in large isospin hypernuclei • cluster structure etc. • fp-shell nuclei : 40Ca(PR08-002), 51V, 52Cr • Beyond fp-shell :89Y • ~Single-particle potential • Distinguishability of a L hyperon • U0(r), mL*(r), .. 3
Setup of the 3rd generation experiment Newly constructed
Comparison of available beam energy between HKS+ENGE andHKS+HES (3rd gen.) (2nd gen.) ENGE HES Acceptable Central Energy (GeV) 0.3 0.4 0.6 0.8 1 Ee’ (GeV) 1.8 1.9 2.0 2.2 2.4 2.5 2.1 Ee at Hall-C (GeV) Etop2pass (GeV) 4.4 4.55 5.0 6.0 Etop1pass (GeV) 9.45 10.3 10.8 12.0
How to avoid background electrons ~Tilt Method~ Backgrounds on e’ arm : e’ from Bremss. & Moeller →Tilt Method e’ Signal e’ associates With virtual photon Background y’ Moeller ring 2.5GeVElectron Beam Energy e’ from Bremss. x’
HES acceptance Acceptance of HES Virtual Photon Energy1.5 GeV 3rd gen. (E05-115) HES1.0 GeV/c Beam Energy2.5 GeV 2nd gen. (E01-011) Enge0.3 GeV/c Beam Energy1.8 GeV ×10 Enge acceptance y’ y’ Moller x’ Brems x’ 10 times virtual photon tagging efficiency
HES detectors Position Detectors EDC1(Honeycomb type) + EDC2(Planer type) Trigger Counters EHODO1+EHODO2 EHODO1,2 ED e’ EDC1 EDC2
Upgrade of HKS Detector package LC Add • Renew boxes of Water Cherenkov (Tohoku U.) • Improved light collection efficiency • Add Lucite Cherenkov (Hampton U.) • Additional information on PID and TOF measurements • Add bucking coil for Aerogel Cherenkov (Florida Int’l U.) • Cancel stray field of HKS dipole (~ 5 gauss) to recover gain of PMT Q-Q-D Bucking Coil Renew
Yield Estimation about 5 times
Simulated spectrum of 51V(e,e’K+)51LTi HKS (8msr ) + HES ⊿E = 300 keV [FWHM] Beam I = 30 [μA] V 100 [mg/cm2] S/N=5 Expected Counts /100KeV/144h SIMULATION - BΛ ( MeV )
Pictures @ TOKIN (Sendai, Japan) HES HKS 1.0GeV/c e’ Splitter 1.2GeV/c K+ CEBAF 2.5GeV Electron Beam
Splitter Magnet 1.72 m
EQ2 Q-Q-D Magnet EQ1 EQ2 EQ1 1.25 m ED
Q-Q-D Magnet Tilt Version
Schedule • Dec 2007 HES departed from Japan • Feb 2008 HES arrives at Norfolk • Mar 2008 Test experiment of detectors at Tohoku Univ. (LNS) • Apr 2008 Tohoku group begins stay at JLab By the end of 2008 Ready to install HES in Hall C
Summary • HES magnets are on the way to JLab • HES detectors are under construction • Part of HKS detectors, WC and AC will be upgraded and LC will be added • Yield is5 times larger than the 2nd generation exp. • Will be ready to install HES by the end of 2008
Various targets E01-011 First Generation E94-107 Hall A Experiment E01-011 Second Generation E05-115 Third Generation PR08-002 Third Generation
HES-HKS momentum acceptance HES 51LTi g.s L S HKS