HALL-A STATUS REPORT

1
HALL-A STATUS REPORT

• Hall A Collaboration Meeting
• December 5-6, 2005
• KEES DE JAGER
• JEFFERSON LABORATORY

Mauro Iodice has kindly agreed to host a wine-and
cheese gathering Monday evening in the Residence
Facility, starting at 530 pm Eric Voutier has
hand-carried a selection of French cheeses If you
attend (most of you, I hope) please pay Heather
the standard 9 contribution
2
Septum Magnets

• Left septum can run at 60-65 µA
• Right septum quenched at 30 µA
• A sweep magnet was constructed for HAPPEx which
  was predicted to reduce heat deposition by factor
  2-4
• HAPPEx-He showed only a very modest increase in
  the max. tolerable current to 35 µA
• However, HAPPEx-II with the hydrogen target could
  run at 58 µA
• In agreement with Eugenes simulation
• Clearly, the neutron production from the helium
  target dumps a significant amount of heat into
  the septa

3
Hall A Approved Proposals PAC 4-27

• 36 Experiments completed
• Backlog 4 years (annual average for Hall A is
  80 days at full funding)

4
Proposals to be submitted to PAC29

• Jeopardy
• E03-003 Polarization Transfer in Wide-Angle
  Compton Scattering B. Wojtsekhowski 17
• E03-004 Measurement of the Single Target-Spin
  Asymmetry
• in Semi-Inclusive Pion Electron Production on
• a Transversely Polarized 3He Target X.
  Jiang 24
• E03-011 Clean Measurement of the Neutron Skin of
  208Pb
• through Parity-Violating Electron Scattering R.
  Michaels 30
• New
• PR06-00 Measurement of the neutron d2 B.
  Sawatsky 13
• PR06-00 PV electron scattering in the resonance
  region P. Bosted 14
• PR06-00 IA Limitations to the (e,ep) Reaction on
  208Pb A. Saha 10
• PR06-00 Strange form factor of the proton at 2
  GeV2 B. Wojtsekhowski 35
• PR06-00 Transversity in p production X. Jiang
  24
• PR06-00 Single Target-Spin Asymmetry in Inclusive
  Scattering T. Holmstrom 1
• Total 158
• Allocation (1372430) 74

5
Publications (incl. submissions) in 2005

• P. Ulmer et al., Polarization Transfer in the
  d(e,ep)n Reaction up to Q2 1.61 (GeV/c)2, PRL.
• J. Kelly et al., Recoil Polarization Measurement
  for Neutral Pion Electroproduction at Q2 1
  (GeV/c)2 near the Delta Resonance, PRC,
  nucl-ex/0509004.
• K.A. Aniol et al., Constraints on the nucleon
  strange form factors at Q2 0.1 GeV2, PLB
  nucl-ex/0506011.
• K.A. Aniol et al., Parity-violating electron
  scattering from 4He and the strange electric form
  factor of the nucleon, PRL nucl-ex/0506010.
• Geraud Laveissiere, et al., Photon
  Electroproduction from Hydrogen at Backward
  Angles and Momentum Transfer Squared of Q2 1.0
  GeV2, PRL hep-ex/0406062.
• S. Escoffier et al., Accurate measurement of the
  electron beam polarization in Jlab Hall A using
  Compton polarimetry, NIM A551, 563 (2005).
• K. Kramer et al., The Q2-dependence of the
  neutron spin structure function gn2 at low Q2,
  PRL 95, 142002 (2005).
• J.J. Kelly et al., Recoil polarization for delta
  excitation in pion electroproduction, PRL 95,
  102001 (2005).
• V. Punjabi et al., Proton Elastic Form Factor
  Ratios for Q2 3.5 GeV2 by polarization
  transfer, PRC 71, 055202 (2005).
• L.Y. Zhu et al., Cross Section Measurements of
  Charged Pion Photoproduction in Hydrogen and
  Deuterium from 1.1 to 5.5 GeV, PRC 71, 044603
  (2005).
• Zein-Eddine Meziani et al., Higher Twists and
  Color Polarizabilities in the Neutron, PLB 613,
  148 (2005)
• D.J. Hamilton et al., Polarization transfer in
  proton Compton scattering at high momentum
  transfer, PRL 94, 242001 (2005).
• Marat Rvachev et al., The Quasielastic
  3He(e,e'p)d Reaction at Q2 1.5 GeV2 for Recoil
  Momenta up to 1 GeV/c, PRL94 192302 (2005).
• Issam Qattan et al., Precision Rosenbluth
  measurement of the proton elastic form factors,
  PRL 94, 142301 (2005).
• Fatiha Benmokhtar et al., Measurement of the
  3He(e,e'p)pn reaction at high missing energies
  and momenta, PRL94, 082305 (2005).
• Total number of Hall A publications PRLPLB
  262, PRC 132, NIM 12.

6
PUBLICATIONS

• Archival papers to be completed in the next year
• E89-044 3He(e,ep)
• E91-026 deuteron A and B
• E93-050 VCS
• E94-010 GDH
• E99-007 GEp-II
• E99-114 WACS
• Achievements to date
• E89-003 16O(e,ep) published
• E91-010 HAPPEx-I published
• E91-011 N-gt? submitted
• E93-027 GEp-I published
• E94-012 H(???)po published
• E94-104 ?n -gt p-p published
• E95-001 GMn circulating
• E99-117 A1n published
• Central repository of figures and publications on
  Hall A webpage
• Please submit figures of all publications to Rob
  Feuerbach
• Please send copy of all publications to Heather
  simultaneous to submission

7
Scheduled Experiments in Hall A

• Exp Title Spokespersons
• Dec-Feb Installation of polarized 3He target and
  Big Bite
• Mar-May E02-013 Measurement of GEn at High Q2 G.
  Cates, B. Reitz,
• B. Wojtsekhowski
• Jun Back to standard configuration
• In summer Hall A runs only if in parallel to G0
  backward at low energy
• E05-103 Low-Energy deuteron photodisintegration R
  . Gilman
• E05-004 A(Q) at low Q R. Gilman
• Sep-Oct E03-105 Polarization transfer in
  4He(e,ep) S. Strauch
• Dec-Mar E04-018 Elastic scattering off 3,4He M.
  Petratos
• plus possibly one more standard configuration
  experiment (E03-101, E04-107, E04-002)
• FY07 run mainly BigBite plus polarized 3He
  experiments
• FY08 HAPPEx-III, Lead Parity, Pentaquark search
• Budget consequences not yet clear.

8
Hall A Schedule (Tentative!)
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Budget and Long-Term Outlook

• Lehman Review (July 12-14) was very successful
• However, CD-1 still not approved
• FY06 budget does mention support for PED
• Kovar has expressed strong support for 12 GeV
  upgrade even after FY06 budget was decided on
• New improved design for the MAD spectrometer in
  Hall A
• After spectrometer review Larry Cardman stated
  that a new review of all upgrade instrumentation
  should happen in early 2006