1. Hall A collaboration meeting, June 23-24, 2005, 1 Operated by the Southeastern Universities Research Association for the U.S. Department Of Energy Thomas Jefferson National Accelerator Facility HALL-A STATUS REPORT Hall A Collaboration Meeting June 23-24, 2005 K EES DE J AGER J EFFERSON L ABORATORY

2. Hall A collaboration meeting, June 23-24, 2005, 2 Operated by the Southeastern Universities Research Association for the U.S. Department Of Energy Thomas Jefferson National Accelerator Facility GENERAL INFORMATION Significant progress on archival papers E91-010HAPPEx-I published E89-003 16 O(e,ep) published E93-027G E p -I published E99-117A 1 n published E95-001G M n circulating -Waiting on E91-026 (A and B), E94-010 (GDH) and E91-011 (N-> ) 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 With deep regret there will be no borrel this time (or any time soon) New lab policy requires an AD to be present, when alcoholic beverages are served on site, and I refuse to ask Larry/Dennis to do this

3. Hall A collaboration meeting, June 23-24, 2005, 3 Operated by the Southeastern Universities Research Association for the U.S. Department Of Energy Thomas Jefferson National Accelerator Facility Publications (incl. submissions) in 2004-II K.A. Aniol et al., Constraints on the nucleon strange form factors at Q 2 ~ 0.1 GeV 2, PRL; nucl-ex/0506011 K.A. Aniol et al., Parity-violating electron scattering from 4 He and the strange electric form factor of the nucleon, PRL; nucl-ex/0506010 K. Kramer et al., The Q 2 -dependence of the neutron spin structure function g n 2 at low Q 2, PRL; nucl-ex/0506005 J.J. Kelly et al., Recoil polarization for delta excitation in pion electroproduction, nucl-ex/0505024 D.J. Hamilton et al., Polarization transfer in proton Compton scattering at high momentum transfer, PRL; nucl- ex/0410001 Geraud Laveissiere, et al., Photon Electroproduction from Hydrogen at Backward Angles and Momentum Transfer Squared of Q 2 = 1.0 GeV 2, PRL; hep-ex/0406062 V. Punjabi et al., Proton Elastic Form Factor Ratios for Q 2 = 3.5 GeV 2 by polarization transfer, PRC 71, 055202 (2005) Zein-Eddine Meziani et al., Higher Twists and Color Polarizabilities in the Neutron, PLB 613, 148 (2005) Issam Qattan et al., Precision Rosenbluth measurement of the proton elastic form factors, PRL 94, 142301 (2005) Marat Rvachev et al., The Quasielastic 3 He(e,e'p)d Reaction at Q 2 = 1.5 GeV 2 for Recoil Momenta up to 1 GeV/c, PRL94 192302 (2005) Fatiha Benmokhtar et al., Measurement of the 3 He(e,e'p)pn reaction at high missing energies and momenta, PRL94, 082305 (2005) Charles Hyde-Wright and Kees de Jager, Electromagnetic Form Factors of the Nucleon and Compton Scattering, Annu. Rev. Nucl. Part. Sci. 54, 216 (2004) Xiaochao Zheng et al., Precision Measurement of the Neutron Spin Asymmetries and Spin-dependent Structure Functions in the Valence Quark Region, PRC 70, 065207 (2004) Kevin Fissum et al., The dynamics of the quasielastic 16 O(e,e'p) reaction at Q 2 = 0.8 GeV 2, PRC 70, 034606 (2004) Alexander Deur et al., Experimental Determination of the Evolution of the Bjorken Integral at low Q 2, Phys. Rev. Lett. 93, 212001 (2004) Moskov Amarian et al., Measurement of the Generalized Forward Spin Polarizabilities of the Neutron, Phys. Rev. Lett. 93, 152301 (2004) Geraud Laveissiere et al., Measurement of the Generalized Polarizabilities of the Proton in Virtual Compton Scattering at Q 2 = 0.92 and 1.76 GeV 2, Phys. Rev. Lett. 93, 122001 (2004)

4. Hall A collaboration meeting, June 23-24, 2005, 4 Operated by the Southeastern Universities Research Association for the U.S. Department Of Energy Thomas Jefferson National Accelerator Facility Hall A Approved Proposals PAC 4-27 32 Experiments completed Backlog ~3.5 years (annual average for Hall A is ~90 days at full funding)

5. Hall A collaboration meeting, June 23-24, 2005, 5 Operated by the Southeastern Universities Research Association for the U.S. Department Of Energy Thomas Jefferson National Accelerator Facility Proposals to be submitted to PAC28 Jeopardy E02-101Exclusive Study of Deuteron Electro- Disintegration near ThresholdK. Wang(16) PR05-102Measurement of A x and A z Asymmetries in the Quasi-Elastic 3 He Reaction (E02-108) S. Sirca15 New PR05-105Investigations of dynamical relativistic effects in the nuclear medium using the 208 Pb(e,ep) 207 Tl ReactionA. Saha9 PR05-112Constrain d-quark polarizationX. Jiang24 PR05-103Low-Energy Deuteron PhotoproductionR. Gilman14 PR05-104High-Energy Neutral Pion PhotoproductionR. Gilman22 PR05-110Coulomb Sum RuleS. Choi26 PR05-107Parity Violation in the Resonance RegionP. Bosted15 PR05-109HAPPEx-IIIK. Paschke30 Total155 Allocation(20+16+15)51

6. Hall A collaboration meeting, June 23-24, 2005, 6 Operated by the Southeastern Universities Research Association for the U.S. Department Of Energy Thomas Jefferson National Accelerator Facility Septum Magnets Left septum can run at 60-65 µA Right septum quenched at 30 µA After opening up the upper half, paper tissue and tape was found (and removed) in the helium lines However, cooling it down in February did not show big improvement A sweep magnet has been constructed for HAPPEx which is expected to reduce heat deposition by factor 2-4 Next test: can septa run with 100 µA on 20 cm LH2 (for HAPPEx)?

7. Hall A collaboration meeting, June 23-24, 2005, 7 Operated by the Southeastern Universities Research Association for the U.S. Department Of Energy Thomas Jefferson National Accelerator Facility Scheduled Experiments in Hall A ExpTitleSpokespersons MayInstallation of septa Jun E94-107High-Resolution 1p-Shell Hypernuclear Spectroscopy S. Frullani, F. Garibaldi Jul-NovE99-115Constraining the Nuclear Strangeness Radius in PVESK. Kumar, D. Lhuillier E00-114Parity Violation from 4 He at Low Q 2 : D. Armstrong, R. Michaels A Clean Measurement of Rho Dec-FebInstallation of polarized 3 He target and Big Bite Mar-MayE02-013Measurement of G E n at High Q 2 G. Cates, K. McCormick, B. Reitz, B. Wojtsekhowski JunBack to standard configuration E02-004A(Q) at low Q (possibly in parallel to G 0 backward at low energy) E04-018Elastic scattering off 3, 4 He E03-105Polarization transfer in 4 He(e,ep) plus at least one more standard configuration experiment (E03-101, E04-107, E04-002) FY07run mainly BigBite plus polarized 3 He experiments FY08Lead Parity, Pentaquark search and if possible DIS-Parity

8. Hall A collaboration meeting, June 23-24, 2005, 8 Operated by the Southeastern Universities Research Association for the U.S. Department Of Energy Thomas Jefferson National Accelerator Facility Hall A Schedule (Tentative!)

9. Hall A collaboration meeting, June 23-24, 2005, 9 Operated by the Southeastern Universities Research Association for the U.S. Department Of Energy Thomas Jefferson National Accelerator Facility 12 GeV Upgrade Spectrometer Mini-Review (January 4-5) At this time, the option that has the best combination of figure of merit and the least risk that covers most of the physics appears to be the HMS+SHMS configuration NSAC charge on Implementation of 2002 LRP Highest priority to 12 GeV Upgrade House and Senate markups (to 408 and 420 M$) make disaster scenarios highly unlikely DOE Science Review (April 6-8) Science was deemed outstanding Major discovery potential in Hybrid Meson Search and Parity Violation Dry run for Lehman Review Went very well Lehman Review (July 12-14) If successful, CD-1 by late September (no PED funds in FY06)

10. Hall A collaboration meeting, June 23-24, 2005, 10 Operated by the Southeastern Universities Research Association for the U.S. Department Of Energy Thomas Jefferson National Accelerator Facility Preliminary Conclusions from Roy Holt The MAD is a bold new advance in spectrometer design that is very promising as a way to reduce the required beam time by at least a factor of two compared to the other configurations for most experiments. Nevertheless, it appears that there is a risk at this time in pursuing this option. Specific concerns which should be addressed before this option is pursued are: Reliability of and effort involved in detector movement and re- calibration after movement, especially in combination with a septum. Effects of relatively large background rates on the performance. At this time, the option that has the best combination of figure of merit and the least risk that covers most of the physics appears to be the HMS+SHMS configuration. If time permits, we advise that the feasibility of the MAD option should be studied thoroughly. In a further evaluation of the spectrometer configurations, a difficult single arm experiment such as x>1 should be included.

11. Hall A collaboration meeting, June 23-24, 2005, 11 Operated by the Southeastern Universities Research Association for the U.S. Department Of Energy Thomas Jefferson National Accelerator Facility Hall A Activities MAD (instrumentation review expected before summer of 2006) Structural integrity: UMd engineer is performing simulations Background: taskforce headed by Jian-Ping Chen is developing detailed simulations for five characteristic experiments Dedicated set-up(s) for parity-violating program Moving future HKS program to Hall A (talk by Hashimoto) Cheap spectrometer using Q2 and Q3 for less than 1 M$ Talk by John LeRose Needs expressions of interest Continuation of 6 GeV program Hall A Collaboration is invited to provide feedback and dedicated support in developing these future activities

12. Hall A collaboration meeting, June 23-24, 2005, 12 Operated by the Southeastern Universities Research Association for the U.S. Department Of Energy Thomas Jefferson National Accelerator Facility Summary Hall A research program vibrant Many exciting new results Good progress on archival publications Septum magnets are (finally!) operational Scheduling for next five years will be difficult 12 GeV project is gaining momentum and broad recognition ¤Keep up the good work!