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Israeli Participation in Heavy Ions and Fixed Target Experiments (HE and Nuclear Physics)

Israeli Participation in Heavy Ions and Fixed Target Experiments (HE and Nuclear Physics). Restricted ECFA meeting. Israeli Academy of Science, Jerusalem. Friday, 21 May 2005. E. Piasetzky. School of Physics and Astronomy. Tel Aviv University. Outline:.

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Israeli Participation in Heavy Ions and Fixed Target Experiments (HE and Nuclear Physics)

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  1. Israeli Participation in Heavy Ions and Fixed Target Experiments (HE and Nuclear Physics) Restricted ECFA meeting Israeli Academy of Science, Jerusalem Friday, 21 May 2005 E. Piasetzky School of Physics and Astronomy Tel Aviv University

  2. Outline: • Scientific program andphysics highlights. Hardware Contributions. Experimental groups in Israel: People, group size, and activities. Period: 1990-2005 Summary and overview. More information can be found in slides 37-80 which do not have time to present.

  3. Scientific program measurement of the pion valence – quark momentum distribution. Experiments at Fermilab: Observation of Color-Transparency in Diffractive Dissociation of pions. E 665 E 781 (SELEX) E 791 Search for particles made of 5 and 6 quarks. Polarization Measurement of the Lambda produced in Deep inelastic muon scattering. Double Charm Baryon Spectroscopy. NA-47 (SMC) at CERN Spin structure of the nucleon. COMPASS at CERN Determination of the gluon polarization. Π Polarisabilities via Primakof reaction. Relativistic heavy Ion: 1999- NOW PHENIX / RHIC at BNL 1990-1999 NA45 / CERES at CERN Fixed Target particle physics experiments: 500-50 GeV

  4. EVA at Brookhaven National Lab. Scientific program TRIUMF: Measurements of pion integral cross sections for low and the 3,3 resonance energy regions. PSI : Precision measurement of elastic scattering of low energy π+ ,π- on nuclei. Total π- p SCX cross sections between 40-240 MeV. Experiments at Jefferson Lab. E02-013, E93-0026 Measurement of the neutron charge FF: GEn E01-015 E03-101 Measurement of short range correlation in nuclei. Hard photo-disintegration of a pp pair. E850 / EVA Study of hard proton induced reactions. Measurement of short range correlation in nuclei. Measurement of the π+ polarizabilities. Mainz Microtron MAMI A2 collaboration 1-20 GeV 20-300 MeV

  5. Scientific program TRIUMF Radioactive beam and Neutral Magneto-Optical atom Trap Symmetry Tests in β Decay. Radioactive nuclear beams ISOLDE / CERN Measurements of ground-state magnetic moments of short-lived Mirror Nuclei. Precision measurement of the 7Be(p,gamma)8B cross section. Parity non-conservation in 180mHf. ( An experiment to be run in 2005). SARAF (Soreq Applied Research Accelerator Facility) Study of nuclear astrophysics reactions using ion beams. 0-2 MeV

  6. physics highlights Main CERES Result: strong enhancement of low-mass dileptons hinting at Chiral Symmetry Restoration • Strong enhancement of low-mass e+e- pairs in A-A collisions • (w.r.t. to expected yield from known sources) • No enhancement in p-Be and p-Au • Quantitative explanation requires: • thermal radiation from high-density • with in-medium modification of the • intermediate  meson hinting at • chiral symmetry restoration HG+-    *  e+e- Spectral shape broadening dropping  meson mass free  meson hadron cocktail

  7. Main PHENIX Results 0 yield w.r.t. to pp collisions d-Au Au-Au physics highlights • discovery of jet quenching (suppression of high pT particles). • very high energy density state (30-100 times dense than normal nuclear matter). • rapid equilibration. • strongly interacting • system exhibiting • collective behavior. • suggestion of a perfect • primordial fluid (almost • zero viscosity), behaving • more like a liquid, not as • a gas. The first PHENIX paper (PRL 86, 3500 (2001)) is based on an analysis of the WI group.

  8. physics highlights The light-cone asymptotic wave function describes the data well for Q2>10 (GeV/c)2. Q2~8 (GeV/C)2 Q2~16(GeV/C)2 E 791 / FNAL : Direct measurement of the pion valence – quark momentum distribution The pion wave function can be expanded in terms of Fock states: The valence (first) state with the minimal gluon content, very small size, large mass, is about 25% of the light cone wave function. Diffractive dissociation of 500 GeV/c π- into di-jets from a platinum target at FNAL exp 791 allows to measure the internal momentum distribution of the valence quarks in this state.

  9. SELEX, the charm hadro-production experiment (E781) at Fermilab opened a new horizon for charm baryon spectroscopy. physics highlights SELEX 4 double charm states .

  10. SELEX : physics highlights First observation of the Doubly Charmed Baryon PRL 89 (2002) 112001 Confirmation via another decay mode: Analysis done at TAU Submitted to PRL ( hep-ex / 0406033) The two decay modes give consistent mass. The averaged mass is 3518±3 MeV/c2. The relative branching ratio: is

  11. physics highlights ΔG/G = 0.06 ± 0.31stat. ± 0.06syst. cc How ΔG/G is measured Photon-Gluon Fusion (PGF) N ΔG/G from high pt hadron pair, Q2 > 1 Open charm At this point only raw asymmetry is available. Preliminary result based on 2002-2003 data.

  12. p p e HRS HRS n e n-array Experimental setup: BigBite physics highlights Measurement of short range correlations in nuclei. E 01 - 015 The goal: To study nucleon pairs at close proximity and their contribution to the large momentum tail of nucleons in nuclei. “Redefined” the problem in momentum space The method: A pair with “large” relative momentum between the nucleons and small CM momentum.

  13. physics highlights The extra repulsion observed in pionic atoms data was confirmed by the scattering data. In medium modified pion decay constant reconcile the π-nucleus and πN interactions. This is consistent with a recent suggestion by Weise et al. using chiral restoration model. Precision measurement of elastic scattering of 21.5 MeV π+, π- on Si, Ca, Ni, and Zr. The Goal: Testing the “anomalous” s-wave repulsion as observed in pionic atoms. Method: using the πE3 channel of PSI and the low energy pion spectrometer (LEPS). Results: PRL 93 (2004) 122302.

  14. Hardware Contributions:

  15. All the gas detectors for CERES were designed, constructed and operated by the WI group. CERES Spectrometer: 1992 Double RICH spectrometer – no real tracking Readout chambers of the two RICH detectors CERES Spectrometer: 1995 Add tracking with a doublet of SiDC before, and a pad chamber after the double RICH spectrometer Add Pad Chamber CERES Spectrometer: 1999 Improve tracking and mass resolution with a radial TPC • Readout chambers of the TPC PHENIX Hardware Contributions

  16. Hardware Contributions: Pad Chambers Essential components of the PHENIX particle tracking system. Composed of three layers of pixel detectors PC1, PC2 and PC3. PC1 (design, construction, installation…) is the responsibility of WI group. A sector of PC1 mounted on the drift chamber and ready to be installed on the PHENIX central arm (photo taken in 9/99).

  17. Hardware Contributions: Design construction and operation of HBD Hadron Blind Detector for PHENIX HBD concept ♣ windowless Cherenkov detector (L=50cm) ♣ CF4 as radiator and detector gas ♣ CsI reflective photocathode ♣ Proximity focus: detect blob not ring ♣ Triple GEM with pad readout Final HBD design

  18. Hardware Contributions: Detectors built by the experimental group at Tel Aviv University are moved to be installed in the experimental Hall A of the Jefferson Lab. Scintillator hodoscopes for the BigBite spectrometer Dec. 2004 The n-array

  19. Measurements of ground-state magnetic moments of short-lived Mirror Nuclei Hardware Contributions: Atomic polarization ISOLDE + Tilted-foil polarization + HV Platform + β NMR Static magnetic field + perturbing rf field 60 KeV BEAM 250 kV IN THE FUTURE: REX-ISOLDE

  20. SARAF (Soreq Applied Research Accelerator Facility) Phase II 2009 Phase I 2006 Accelerator Layout Soreq Nuclear Research Center Yavne, Israel 2nd – 6th cryostats 40 SC HWR 176 MHz b0=0.15 1st cryostat 6 SC HWR 176 MHz b0=0.09 176 MHz RFQ 1.5 MeV/u M/q ≤ 2 Accelerator purchased from Accel GmbH, Bergisch-Gladbach, Germany ECR Ion Source 20 keV/u

  21. Accelerator Basic Characteristics A RF Superconducting Linear Accelerator

  22. Experimental groups in Israel: People, group size, and activities.

  23. Weizmann Institute of Science • 3 academic staff • 1-3 post-docs • 2-4 students • Present total staff: 8 people • 9 PhD theses: in the period 1993-2006 The Heavy Ion Group: Itzhak Tserruya Zeev Fraenkel Group leader: Itzhak Tserruya Ilia Ravinovich  More information in slides 37 - 46.

  24. Weizmann Institute of Science 3 scientists 4 post docs 3 students Gvirol Goldring Michael Hass  1-2 technician -years The WI group started its activity at ISOLDE IN 1990. The group is not a member of the ISOLDE collaboration and carried the experiments on an ad-hoc basis. More information in slides 47 - 50.

  25. 2 scientists 4 students • 5 PhD (7 M. Sc.) theses: in the period 1990-2006 Eliahu Friedman Michael Paul More information in slide 51.

  26. 6 scientists 4 students 1 technician Danny Ashery Jonas Alster Avivi Yavin Present active staff : 9 people • 12 Ph.D (14 M. Sc.) thesesin the period 1990-2006 More information in slides 55 - 80. Murray Moinester Jechiel Lichtenstadt Eli Piasetzky

  27. Last but not least: The experimental program was carried in intensive collaboration with the theoreticians here in Israel: Weizmann Institute: Zvi Lipkin Igal Talmi Shmuel Gurvitz  Michael W. Kirson Avraham Rinat Hebrew University: Avraham Gal Ami Leviatan Barnea Nir Victor Mandelzweig Tel Aviv University: Shmuel Nussinov Marek Karliner Naftali Auerbach Benjamin Svetitsky Evgeny Levin Leonid Frankfurt The late: Judah Eisenberg

  28. Summary and overview.

  29. The fixed target and heavy ion program carried by Israeli groups during 1990-2005 was rich and widespread: 0 yield d-Au Au-Au Physics interest: QGP, hadron structure, strong interaction, symmetry tests, nuclear structure and reaction. Energies: RHI: - Fixed target: 0-500 GeV. Accelerators laboratories: CERN ,Mainz, PSI, Fermi., Brookhaven, Jefferson, TRIUMF

  30. Israeli participation

  31. The program has been carried by experimental groups in Weizmann Inst., Hebrew University , and Tel Aviv University. Faculty - 14 The current total number of people doing research in this field (faculty, postDocs., students, technicians): ~ 30. 30 Ph.D. theses in the period 1990-2005. Israeli participation

  32. Funding: I.S.F., B.S.F., G.I.F. ~400,000 €/year FNAL-SPS-RHIC (HE: E>50GeV): ~75% Others: ~25%

  33. Heavy Ion Group of the Weizmann Institute 1990-1999 NA45 / CERES at CERN 1999- NOW PHENIX / RHIC at BNL

  34. Hardware Contributions • CERES: all gas detectors designed, constructed and operated by the WI group: • 1990-92: Readout chambers of the two RICH detectors • 1995: Pad Chamber • 1999: Readout chambers of the TPC • PHENIX • 1999: Design, construction and operation of Pad Chambers • 2003-4: R&D of an Hadron Blind Detector for PHENIX • 2005-6: Design construction and operation of HBD

  35. CERES Spectrometer: 1992 TMAE 2 PPAC + MWPC Pad readout Radiator gas CH4 (γth = 28) Si drift chambers CaF2 window Carbon fiber mirror • First use of RICH detector in HI physics • First use of Si radial drift chambers in an experiment • Double RICH spectrometer – no real tracking • Unique features to cope with the high multiplicities: • High gamma threshold  tiny fraction of charged hadrons emit Cherenkov light • UV detectors upstream of target  not traversed by huge flux of forward particles • Field free region in RICH1 for effective recognition of 0 Dalitz and γconversions

  36. CERES Spectrometer: 1995 Add tracking with a doublet of SiDC before, and a pad chamber after the double RICH spectrometer

  37. CERES Spectrometer: 1999 Improve tracking and mass resolution with a radial TPC

  38. Pad Chambers Essential components of the PHENIX particle tracking system. Composed of three layers of pixel detectors PC1, PC2 and PC3. PC1 (design, construction, installation…) is the responsibility of WI group.

  39. HBD concept ♣ windowless Cherenkov detector (L=50cm) ♣ CF4 as radiator and detector gas ♣ CsI reflective photocathode ♣ Proximity focus: detect blob not ring ♣ Triple GEM with pad readout Very attractive features: • Unprecedented N0 Bandwidth 6 - 11.5 eV  N0 ≈ 800 cm-1  ~35 pe in a 50 cm radiator • Reflective photocathode  no photon feedback • Pad size comparable to blob size (~10 cm2) hadrons: single pad hit, electrons: more than one pad hit • Low granularity:~3000 pads to cover central arm acceptance • Low gain primary charge of at least 10 e/pad  gain of 5 103 is enough

  40. Final HBD design • Acceptance • || ≤0.45 • =135o • pad size • a = 15.6 mm • Number of channels • 2304 • Number of detector modules • 24 • GEM size • 23 x 27 cm2

  41. Management Positions • 1989-91 Initiators of the CERES experiment together with the Heidelberg University group. • 1993-1998: Spokesman of CERES • 2001-4: Member of PHENIX Executive Council • 2004- present: Subsystem manager of the PHENIX HBD upgrade project (I. Tserruya)

  42. Group activities • 60 papers published in the refereed literature • 21 from CERES • 39 from PHENIX • 26 of them published in PRL or PL a) • 9 of them are top cite 100+ in SPIRES-HEP • Over 100 papers published in Conference Proceedings. • Major impact of the WI group • in the dielectron analyses of CERES • in at least 9 papers from PHENIX • 49 invited talks • delivered by members of the WI Heavy-Ion Group at International Conferences or Workshops during the period 1995-2005 • 12 of them on behalf of CERES or PHENIX. • a) First PHENIX paper (PRL 86, 3505 (2001)) based on an analysis of the WI group. Cited 164 times.

  43. The Radioactive nuclear beams Group of the Weizmann Institute ISOLDE / CERN Measurements of ground-state magnetic moments of short-lived Mirror Nuclei. Precision measurement of the 7Be(p,gamma)8B cross section. Parity non-conservation in 180mHf. ( An experiment to be run in 2005).

  44. 23Na (11p + 12n) stable 17Ne (7 p + 10n ) T1/2=4.2 sec Measurements of ground-state magnetic moments of short-lived Mirror Nuclei 23Mg (12 p + 11n ) T1/2=11.3 sec 17Ne (10 p +7n ) T1/2=109 msec FUTURE: 55Ni -- 55Co, 59Zn -- 59Cu …...

  45. Precision measurement of the 7Be(p,gamma)8B cross section 8B is the major source of high-energy solar neutrinos. The discrepancies between measurements of the 8B production cross section before this work were up to 20%, reflecting the systematic problems in these measurements. The new technique: The spallation product ,7Be, produced in a PSI graphite production target were directly implanted, using the 60 keV beam at ISOLDE (CERN) on a copper substrate. The measurements were done using the WI 3 MeV Van De Graaff accelerator. Measurements at a few incident proton energies (with a precision of about 2% ) allow extrapolation to zero energy –as required for the astrophysical studies. PRL 90 (2003) 022501-1

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