Seonho looked at the sharp peak in the 0.86 Gev parallel delta cross section vs nu:

        - Seonho said that the sharpness was due to averaging 5 points together
        - Seonho's fourth order spline fit did not appear to fit the data.  The GDH
            collaboration suggested the Seonho continue with a polynomial fit

        Seonho looked at the systematic uncertainties in the beam energy
        and charge measurement:

        - The systematic error due to beam energy uncertainty can be ignored
        - For the error in the charge measurement, 100 ppm is a good upper bound
            of the relative imprecision of the charge measurement

       Karl Slifer checked the systematics of cross sections:

        - Systematic error of the cross section by comparing the total cross section Vs.
            spectometer difference, they both agree except at the 862 MeV and the first
            period of the 1717 MeV energies
        -  Runs with large charge asymmetry:

         8 runs out of 1052 have ~100,000 ppm asymmetry
         Set limit so that charge asymmetry < 2000 ppm

        - Runs with large deadtime

         For the cross section, 4 runs out of 658 have deadtime > 40%
         For the asymmetry, 16 runs out of 1052 have deadtime > 40%
         These runs will be removed from the data analysis

       - The 3 GeV the transverse delta cross sections for the hadron
           and electron arms don't agree.  Possible reasons are the difference
           in acceptance at the edge and that for Armageddon,
           the H-arm side is 20% thicker than the E-arm
      - For the long paper, the beam trips will be cut out, since when they occur the
          charge asymmetry changes

    Alexandre Deur checked systematic uncertainties:

        - A 5% cross section uncertainty is reasonable
        - 10% uncertainty on unpolarized radiative corrections
        - Nilanga will check the polarized radiative corrections
        - Alexandre pointed out that the wall thickness on Armageddon changes
            by 20%.  The H-arm is 20% thicker than the E-arm, should the error on the
            RC be increased
        - Alexandre checked the error in the sum due to the uncertainty in the pion
            threshold determination and found the uncertainty small

    Conclusions for GDH collaboration:

        - Systematic uncertainties are almost finished
        - Karl will check the scintillators and the large asymmetries
            of the anti-cerenkov events
           - Gordon will consult with Eugene for the errors on the Beam polarimetry ~ 3%
        - For interpolation for the systematic error, the average of Seonho's method and
            the previous method will be used
        - Seonho will check the asymmetry at 3.4 GeV, the lowest TT cross section spectrum, and RC
        - Seonho completed the Neutron extraction

    Discussion on the first PRL for GDH:

        After the seminar by Zein-Eddine Meziani on the final result, (November 30, 2001),
        the collaboration will submit the first PRL

    Back to Main Minutes page.