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HD Project and Future Physics ? What we can have as a strategic device ? New projects: Polarized proton and deuteron target: “HD project” 29 July 2005 M. Fujwawa@rcnp Collaboration with H. Kohri, M. Tanaka, N. Muramatsu, T. Hotta, M. Yosoi, J.P. Didelez, G. Roiulle (ORSAY)
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TOF Dipole Magnet 0.7 Tesla LH 2 Target Start Counter DC2DC3 DC1SVTX AC(n=1.03) LEPS spectrometer ray beam
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Missing mass spectrum p( ,K + ) (1116) 72,500 events p( ,K + ) 0 (1193) 48,900 events 1.5 ~ 2.4 GeV 0.6 < cos cm < 1 Photon beam asymmetry
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Asymmetr y (2) Photon beam asymmetry Vertical = [ 1 + P cos(2 ) ] Horizontal = [ 1 - P cos(2 ) ] N = F acc = P cos(2 ) N : K + photoproduction yield : K + azimuthal angle P : Polarization of photon n : Normalization factor for N v dd dvdv dd d unpol dd dd dhdh dd dd nN v - N h nN v + N h For all events
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Spin observables? Beam asymmetry Nakayama & Tsushima: Phys. Lett. B583, 269(2004) for the positive parity of the beam asymmetry is significantly positive, whereas for the negative parity of beam asymmetry is significantly negative
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Physics motivation Nucleon Spin Sum Rules Gerasimov-Drell-Hearn (GDH) Forward Spin-Polarizability ss contents in nucleon + spin-parity SPIN CRISIS !
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+ spin-parity determination Zhao and Al-Khalili PLB585(2004)91 Beam-target double polarization asymmetry 1/2 + 1/2 -
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meson photoproduction @ LEPS of SPring-8 Studying diffractive channels as a tool for non-perturbative QCD (Pomeron structure, search for glueball, f 2 ’-meson trajectories, etc ) Search for exotic processes as ss-knockout Henley et al. [94] Titov, Yang, Oh [94-98 ] Non-polarized observables are not suitable for this study
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ss contents in proton ・ -meson: ~ ss p p pomeron exchange + exchange + ss knock-out Study small amplitudes by interference double polarization asymmetry
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Reconstructed events (K + K - event) Missing mass ( ,K + K - )X (GeV) events /2.5MeV Proton(938) =10 MeV Invariant mass (K + K - ) (GeV) events /2.5MeV Invariant mass square (K + K - ) (GeV 2 ) Invariant mass square (K - p) (GeV 2 ) Selections for event (KK mode) |M(KK)-M |< 10 MeV |MM(( ,K + K - )X)- M proton |< 30 MeV
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Titov et al. PRC58(1998)2429 beam-target double spin asymmetry for p p
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Polarization observables with linearly polarized photon ( in meson rest frame) Decay Plane // natural parity exchange (-1) J (Pomeron, Glueball, scalars`) Decay Plane unnatural parity exchange -(-1) J (Pseudoscalar mesons ) K+K+ K-K- K+K+ K+K+ K-K- Decay direction // to direction of beam Spin-flip processes in Pomeron and f 2 ’…
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ss-quark content of proton and neutron |p = |uud + |uudss
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This simple picture depicts pairs of strange quarks as they pop into and out of existence alongside the permanent quark residents of the proton. Nuclear physicists have found that strange quarks, though present for just tiny fractions of a second at a time, also contribute to the proton's properties. Image: JLab SPIN CRISIS at least 10% ss content in nucleon G0 experiment at JLAB: Anapole moment Z0Z0 e e
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Double polarization asymmetry meson: pure ss -
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Beam-target asymmetry and exotic processes with unnatural parity exchange ( -knockout) ss LEPS Spring-8
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C BT = ( p - BG ) – ( A - BG ) ( p - BG ) + ( A - BG ) = p – A p + A - 2 BG BG R= p + A )/2 C BT C BT () 2 = {1-C BT (1-R)}+C BT R 2 222 2C BT (1-R) 22 p pp () 2 + R2R2 (1-R) 2 BG BG () 2 Error estimation for C BT measurement
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Polarization in thermal equilibrium | -1/2> |+1/2> E=g N B If I=1/2, proton : g p N B/2kT=0.00101 B(T)/T(K) electron: g e B B/2kT=0.67 B(T)/T(K)
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Principle of HD Longstanding effort at Syracuse, LEGS/BNL ORSAY 10-20 mK 15-17T 80% for H, 20% for D (vector) 20% 70% in D with DNP
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Thanks to H. Toki for the RCNP- ORSAY collaboration HD distillator RCNP In 2006
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Present status LEGS/BNL ( Syracuse) Future RCNP ( Spring-8) goal: 10m K, 17 T
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LEGS@BNL
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Polarized HD NMR Coils Solenoid Coil Saddle coils Liquid 3 He (0.5 K) Liquid 4 He (4.2 K) 70 K Shield Al Wires HYDILE target @Orsay
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偏極陽子・重陽子標的装置
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RCNP 低温施設 施設整備 電力ライ ン 冷却シス テム
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1220mm 170mm 70mm Mixing Chamber Nb3Sn joints & Protection Circuit NbTi joints & Switch Main Coil Correction Coil Null Coil Rough dimensions of the magnet 400mm 600mm 550mm 1K Pot 538mm
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Field profile around Magnet Center Field profile around Mixing Chamber
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R(mm) 70mm Mixing Chamber 170mm 1K Pot 538mm R(mm) Z(mm) B(T) Stray Field profile around Magnet
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Road map (5 years from 2005 fiscal year) for Studies of Hardron structures 2008200720062005 ( DR + SC magnet ) 2009After 2010Fiscal year Spin and parity determination of + particle HD gas 、 IBC 、 TRC 、 others TRC NMR DR+IBC SRC New DR Scintillator ball 、 TPC Scintillator ball Installation of new detectors Roma2, ORSAY HD at Spring-8 、 meson production, K-production, hidden strangness of nucleon New TPC design HD polarization Charged meson production Experiments with magnetic spectrometer Polarized HD SPring-8 Collaboration with Roma2 、 ORSAY 、 US Neutral particle detection with Scintillator ball total 92,507 kyen 103,000 93,000 New badget 83,505 96,000 86,000 total About 480,000 kyen IBC cryostat and new Data taking system
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Summary C BT measurements with polarized target HD at SPring-8 p 0 + p + p K + , K+ + p + p JAPAN-KOREA-CHINA Three country conference in February 2006 “Hadron and Nuclear Physics with Photons” supported by RCNP and APRC
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