11/21/2002

Spin Duality preparation:

• Vince:

     - Wall thickness on Exodus,
     - with Kevin, worked on field mapping.

• Seonho:

     - left arm cerenkov: PMT #9 has to be changed,
     - right arm cerenkov: all PMT have to be changed.

• Patricia:

     - will test new PMTs,
     - preshower-shower check in the right arm:
             looking for missing blocks,
             mapping the shower detector.

g2n analysis:(Kevin)

      1) windows false asymmetry with react_z cut only and then with PID cuts.

      2) fit g1 and g2:
              - Put data points in bins,
              - constrained g1 to go to 0 at 0,
              - include GDH data in his fit.
              - Jian-Ping suggested to use MAID.

GDH analysis:(Karl)

      Cross section analysis:

         1) tried to estimate the systematic errors on radiation length: some looks to optimistic (Jian-Ping).

         2) showed the comparison for 2 different cells in Q.E. region: after R.C. they agree well.

         3) showed comparison between hadron arm and electron arm:
                 - for 2 GeV cross sections agree better than 5% after R.C,
                 - for 1.7GeV and 3.3GeV the agreement is worse --> suspect incorrect thickness for hadron,
                 - Jian-Ping suggested to use these spectra to determine the thickness.

11/14/2002

Spin Duality preparation:

     - installation will start on Tuesday.
     - need to rotate at 19deg the target system (like for E94-010) --> cannot run at 15deg
     - Survey on Thursday
     - we will have 1 or 2 days of optics commissioning
     - Laser alignment and water calibration: after Christmas.
     - need Nitrogen and Empty target run for each kinematics.

Target lab status:

     - testing the new Ice-cone cell from W&M: Veronica

Target/g2n analysis:(Kevin)

      g2n:
          - 2 studies: windows false asymetry with react_z cut only and then with PID cuts.
          - Looked at ³He parity violation with his data
          - fit on g2: need more work
          - RC

GDH analysis:(Karl)

     1) study of the error on the unpolarized ³He cross-section before RC:

         error on elastic tail:

              - Nitrogen-14 (form factors from Dally et al. PRC2, 2057 (1970)): for Q²<0.12GeV² --> relative error < 5%; for higher Q² --> rel. error jump to 20%
              - ³He (form factors from McCarthy(1970) and Amroun(1994)): relative error < 5%; at E=3.4GeV: huge error at nu <0.9GeV but then less than 5%

         Q² dependance of QFS model:

              - at QE peak: huge variation of (QFS/data) for Q²<0.1GeV²
              - at delta peak: constant

         Estimate of error on Nitrogen cross section RC:

              - closed to the tail: 20% and elsewhere <5%

         Summary of the error study:

              - statistical: 2-3% on the total measured cross section --> multiplied by 0.9 to get statistical on unpolarized ³He cross section
              - systematic:
                   --> 3.9-4.9% on the total measured cross section
                   --> 5% from comparison of Amroun and McCarthy FF on ³He elastic tail
                   --> 7-52% from comparison of QFS QE peak to carbon data on Nitrogen cross section calculated from QFS
                   --> 10% on radiative correction of Nitrogen cross section
                   --> 20% from error on Dally FF on Nitrogen elastic tail.

         Systemactic error on cross section before RC: <8% at E=2581MeV; about 10% at E=862MeV

     2) RC systematic: at E=2581MeV --> from RC <2%, from raw cross section about 5%, and the total systematic on "clean" cross section 5-10% (15% at lowest energy and 5% all others)

     Plan:
         - working on smoothing/interpolating cross section and propagating error through RC.
         - expect to have cross section completely done including short note by weekend.