Minutes of the E00-102 Meeting Thursday, August 15 2002 Fissum KF/WH/BR o Kevin showed the poster that he and Mattias developed for the Gordon Conference. There were no major objections to its content (we noted that it was not quite centered on the A0 page, and that ALT was defined in terms of d6sigma instead of d5sigma), so we have labelled it as the final version. If you would like to see it yourself, please visit the experiment homepage. There are full-size, a4, and USLET version archived there for download. o we noted that we have not a single good photo of the waterfall target which shows the water flowing. Maybe we can shake one loose for future posters and talks. o Kevin showed the draft PRC article. Nilanga has provided the cross sections and structure functions for the continuum in table form now, so these will be added. The p-shell writeup is currently being reviewed and critiqued by Jim Kelly and Jose Udias. We are waiting for a decision from Jan Ryckebusch regarding his possible involvement. o Bodo summarized in detail the substantial progress he has made with the optics work for the HRSl. Recall this was the static spectrometer at 4 GeV/c during E00102. He started with two HRSl databases, one from (probably) NDelta for something like 4 GeV/c, and one from e97111, reoptimized with e97111 optics data taken at 0.840 GeV. I'll call the former HI and the later LO. His goal was to compare the two. We are only concerned with the HI results for e00102. 1. there were alot of bugs in the databases he began with that he ironed out. 2. detector offset optimization. While the offsets did need adjusting, both HI and LO did equally well. 3. ytg reconstruction tested. Survey and reconstruction agree to within +/- 0.5 mm for HI and LO. There are some systematic trends in the results which could in principal be removed, but it is not clear that this will gain us anything. 4. angular reconstruction tested. HI is within +/- 1 mrad, LO is within +/- 3 mrad for theta. For phi, HI is within +/- 0.5 mrad, and LO is within +/- 0.75 mrad. o Bodo requested that his analysis of the survey data be independently double-checked, but if there are no errors, then the HI database (with the newly reoptimized detector offsets) is probably AOK. Note: no dp_kin or Emiss optimization has yet been attempted. However, since the reconstructions are fine, these are probably fine too. We discussed what type of "peaked" delta-scan data we might have. Kevin will check the runplan. o Bodo then presented the plan-of-attack for the HRSr. Recall we took coincidence sieve slit data for the HRSr, allowing punchthroughs. Nilanga's idea was to make a very tight cut on Emiss, which will hopefully remove most of the punchthrough mess and allow us to see the sieve slit pattern and thus proceed as was done for the HRSl. If this does not work, we do anticipate the HRSr optics to be just fine at the roughly 1 GeV/c excitation we used. Bodo will pursue this. o summary: HI (with reoptimized detector offsets) looks good for the HRSl. Probably no need for dp_kin or Emiss optimization, but we may try anyway if the data exists. Probably no need for any work for the HRSr, but Bodo will pursue the punchthrough details. WARNING: the waterfall target with all its foils and windows as well as the scattering chamber windows and the spectrometer windows needs to be built into the header file before physics analysis can begin. o Wendy has been working on tracking the spectrometer mispointing a la Rikki's work from NDelta (there is a report at the NDelta website). Her plan of attack is to: 1. perform a complete mispointing analysis for the HRSl. We have surveys for this spectrometer. Since it was static, we should not see any changes in a striplined presentation of the results. 2. ASSUMING NO CHANGES IN THE HRSL MISPOINTING, it becomes the benchmark. Then examine the mispointing of the HRSr. Start at the startup angle, where we also have a survey and determine the mispointing. Then ASSUME the LVDTs worked and push through all the data looking generating the mispointing of the HRSr. Both the HRSr and the HRSl should reconstruct the same target. If they don't, this indicates a problem with the LVDTs. Hopefully there is no problem. 3. IF A PROBLEM IS IDENTIFIED, that is OK. Because we know the HRSl is OK, we can force the reconstruction to be what the HRSl says it should be and just ignore the LVDT information. o Kevin has been in contact with Jose Udias, and it has become clear that building the experiment in software needs to be made a high priority. So he will go through the experiment database Mattias built and extract all the "as-run" parameters to create a "golden" set of MCEEP input decks. These identical decks will then be used in both the theoretical and experimental analyses. The exact cuts used in the data analysis will ultimately be built into these decks. That way we can use the exact acceptances in the theoretical acceptance averaging (as well as quantify the systematic uncertainty). o we decided we would like to have another meeting on Friday September 6th at 14.00. This choice of date and time has been influenced by firm travel schedules. Please voice any objections to this as soon as possible, because we don't have a lot of freedom to move this around.