Elton: The attachment contains the files with correct spectra. E_gamma = 60 MeV; theta = 90 deg: File e60t90-1st_layer-log.ps contains Npe spectra for downstream (left panels) and upstream readouts (right panels) for 45 pe/MeV (top panels), 23 pe/MeV (middle panels) and 6.2 pe/MeV (bottom) conversion factors. (Viz., the middle panels correspond to the Fig.9 of gluex-doc-1300, and the bottom panels correspond to Fig.11 if you forget about very small correction factors you applied for 20-cm shift). Note huge counts in the zero-photoelectrons channel. File e60t90-1st_layer-lin.ps is the same but with linear Y-axis (zero-spike is cutted-off to make the spectrum visible). E_gamma = 2000 MeV; theta = 20 deg: Files e2000t20shift-1st_layer-log.ps and e2000t20shift-1st_layer-lin.ps As you can see, the mean values and the shapes of the spectra differ dramatically from that you put in the gluex-doc-1300 note. Andrei > Elton: > > What did you plot in the figure 9 of the gluex-doc-1300 note? > > The caption says that it's "maximum number of photoelectrons detected in > the first layer". What's that? > > If you meant the sum of photoelectrons in the four cells of the first > layer, the spectra you show looks strange: with your 23 pe/MeV conversion > factor, the means of your downstream and upstream spectra are 34.25 and > 95.19 (respectively) that is significantly bigger values than we have in > our report for 45 pe/MeV conversion for the sum of four cells of the first > layer (24.56 and 55.81 respectively, see Figs.27 and 23 of gluex-doc-1301 > or the attachment to this e-mail). Because you used the ntuple that were > produced by Irina, your numbers must be SMALLER than ours by the factor > (23/45). > > Most probably, you used wrong variables from the ntuples. I did not check > it, but you might have the same problem with your figures 10,11,12 also. > > Another issue is that for photoelectrons you can not just scale the > spectra is you use another MeV-to-pe conversion factor. Irina will prepare > the correct figures for you tomorrow. > > Sorry, > Andrei > > > > >> >> Dear collaborators, >> >> I have uploaded a new version of the cover document, including a >> summary. >> Please send me any feedback by noon JLab time, so I can place final >> documents on the web site for reviewers. >> >> Thanks, Elton. >> >> Elton Smith >> Jefferson Lab MS 12H5 >> 12000 Jefferson Ave >> Suite # 16 >> Newport News, VA 23606 >> elton@jlab.org >> (757) 269-7625 >> (757) 269-6331 fax >> >
e2000t20shift-1st_layer-log.ps
e2000t20shift-1st_layer-lin.ps