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Hi Heiko, the error on S/P from MC enriched goes from 10-15% in the first mX bins to higher values, reaching 100% above 3.7 GeV or so. You can read these numbers from cells I4-I13 and K4-K13 of the spreadsheets in http://www.slac.stanford.edu/~bozzi/SoverP/SoverPFullRew.sxc in addition to consider the uncertainty on the double ratio on the depleted sample, we also need to correct the MC by the central value (1.328). Also, I would really like to see what happens by cutting the modes with pi0s in the garbage... Concezio. Heiko Lacker wrote: > Hi Concezio, > > indeed, S and P are anti-correlated which increases the errors. > > What puzzles me a bit is the fact that the chi^2 is too good. In > other words: At large mX the S/P value should fluctuate more than > it is observed. > > If we believe in a constant the systematics on the individual mX bin > for the double ratio would (e.g. for IP>0.2) be 0.1491/1.328: 11%. > > This should result in an interesting systematic error on DeltaBRBR > when only taking S/P from MC-enriched and by randomizing S/P by 11% > per bin. Of course, one should add still to this error also the error > on S/P from MC-enriched. > > Cheers, > Heiko > > > On Thu, 5 Oct 2006, Concezio Bozzi wrote: > > >> Heiko Lacker wrote: >> >>> * Concezio will produce (S/P)-double-ratios for depleted sample >>> (data/MC) taking into account S/P-correlations in the error >>> calculations in the data-depleted mES fit >>> >>> >> plots which include the correlations are here: >> >> http://www.slac.stanford.edu/~bozzi/SoverP/SoverP_mcdata_depl_020.eps >> http://www.slac.stanford.edu/~bozzi/SoverP/SoverP_mcdata_depl_030.eps >> http://www.slac.stanford.edu/~bozzi/SoverP/SoverP_mcdata_depl_040.eps >> http://www.slac.stanford.edu/~bozzi/SoverP/SoverP_mcdata_depl_050.eps >> >> the spreadsheet used to produce the plots is >> http://www.slac.stanford.edu/~bozzi/SoverP/SoverPFullRew.sxc >> >> Please note that the correlations are not yet taken into account for >> intpur>0.5, as I could not find the appropriate logfile. The effect of >> the correlations is in any case small. Since the S and P are >> ANTIcorrelated (as expected), the error on S/P increase. >> >> Here are the double S/P ratios (MC/data) for different intpur cuts, as >> resulting from a simple p0 fit. Chisquares are also shown. >> >> intpur cut S/P chisquare/nDOF >> 0.20 1.33 +/- 0.15 3.5/9 >> 0.30 1.41 +/- 0.16 2.9/9 >> 0.40 1.19 +/- 0.17 8.7/9 >> 0.50 1.25 +/- 0.17 8.4/9 (no correlations yet) >> >> I would say that data and MC depleted samples agree better and their >> ratio is weakly dependent on mX at higher integrated purity cuts. >> Ciao, Concezio. >> >>