From: Glen Warren (gwarren_at_anti-spam)
Date: 15-May-2003 10:23:46
GEn01 analysis meeting May 14, 2003 ==================================== attended by: Paul, Oscar at UVa Donal, Hongguo, Frank, Nikolai and Glen at JLab *** Revised version adds comments on hszbeam and gave Frank a *** new task. REPORTS *) GMn: Glen has looked received the values of Gmn/dipole from Jim Kelly from his fit (PRC 66 065203 (2002)) and compared them to the Basel fit. He concluded that the best approach was to take the number from Jim Kelly, but increase the error to include the Basel fit. The resulting numbers are Gmn/mu/Dipole = 1.018+-0.011 and 1.054+-0.018 for Q2=0.5 and 1.0 respectively. This still leaves the issue of how this impacts Gen. We agreed to ask Arenhoevel for GMn=1.054*mu*Dipole and Gen=1.1*Galster. *) Background: no progress *) 98 data: no further comments on analysis. Frank suggested that we look at the 98 data for the long paper. We should also look over the field setting codes for 98 and 01 to see if there should be momentum offsets applied to both. *) paper: no progress *) MC work: need to study pion production contributions at Q2=1 *) packing fraction: Nikolai raised the issue of recalculating the packing fraction with the momentum shift, 2) how are we going to handle the rotated stick. Nikolai first guess is that the p.f. will change by 1-2% with the shifted momentum. He can do this be rescaling the momentum in the ntuple, so it should be fairly straight forward. Nikolai also recalled that there was clear evidence that the material in stick 4 had settled. Looking at the pictures of when the stick was pulled, it was clear. Nikolai was asked to represent the evidence for settling. *) stick 3: Nikolai asked how are we going to handle the rotated stick. Nikolai will also review Glen's comments on the dilution factor for stick 3 and make further suggestions. One possibility was to look at proton asymmetries for the left and right side of the cell. *) Pass 4: We agree to remove the 0.33% offset, leave the ndet where it is passed on Glen's examination of the ratio of peak heights which suggested an angle change of only +0.1 degrees. Frank will start the 4th pass immediately. Note that not moving the ndet appears to conflict with ypos comparison of data and MC. *) hszbeam: Glen questions the wisdom of the hszbeam cut. In the past, it was argued that there was clean separation of the cell and 4K shield for Q2=1, thus allowing a 4K shield cut. Glen doesn't see a clean separation in the cut data. Frank says that the separation existed in the uncut data. TO DO Donal *) Ask Arenhoevel for GMn=1.054*Dipole, GEn=1.1*Galster table *) work on paper Glen *) look at 98 and 01 field setting codes Nikolai *) Redo packing fraction with shifted momentum *) Review Glen's comments on the ratio of d.f. for stick 3 and 4 and make suggestions are further course of action. *) Resubmit evidence for settling in stick 4. *) Look at proton asymmetry for left and right half of stick 3 as a means to study differences in d.f. for stick 3 and stick 4. Frank *) Start fourth pass *) accidentals *) Resubmit evidence for separation of 4K shield and cell. Hongguo *) Radiative corrections *) Target field angle uncertainties *) kinematic uncertainties
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