 |
 |
Hi, I post the link where the fit results related to this study can be found: http://www.slac.stanford.edu/~menges/Vub/scra/intpur What we learn already from these results is that the result is stable above say a Integrated Purity cut of 0.4-0.5 and that the statistical error on BRBR would of order 12% which is good. Heiko On Tue, 5 Sep 2006, Wolfgang Menges wrote: > Hi all, > > here are a few numbers from my study of an integrated purity cut. I > have the following cuts: 0.0, 0.1, 0.2 0.3, 0.4, 0.5, 0.6, 0.7, 0.8. The > numbers are from VVFs result.dat file. > > Number of semileptonic events before background subtraction. To get an > impression of what we loose: > > Nsl = 105686 > Nsl = 105686 > Nsl = 105686 > Nsl = 90040.9 > Nsl = 70120.1 > Nsl = 59346.9 > Nsl = 43481.7 > Nsl = 29999.7 > Nsl = 14712.2 > > Background subtracted ratio (looks quite stable): > > (Nsl - BG)/Nsl (vub corrected) = 0.929849 > (Nsl - BG)/Nsl (vub corrected) = 0.929849 > (Nsl - BG)/Nsl (vub corrected) = 0.929849 > (Nsl - BG)/Nsl (vub corrected) = 0.929883 > (Nsl - BG)/Nsl (vub corrected) = 0.929295 > (Nsl - BG)/Nsl (vub corrected) = 0.929081 > (Nsl - BG)/Nsl (vub corrected) = 0.928474 > (Nsl - BG)/Nsl (vub corrected) = 0.928204 > (Nsl - BG)/Nsl (vub corrected) = 0.927771 > > The pstarfactor: > > pstarfact 1.05571 +- 0.0161501 > pstarfact 1.05571 +- 0.0161501 > pstarfact 1.05571 +- 0.0161501 > pstarfact 1.04933 +- 0.0171875 > pstarfact 1.04953 +- 0.0194575 > pstarfact 1.04083 +- 0.0207942 > pstarfact 1.03212 +- 0.0231472 > pstarfact 1.01948 +- 0.0269841 > pstarfact 1.00562 +- 0.0377533 > > And finally the partial BRBR: > > PartialBRBR = 0.0139225 +- 0.00116947(stat) +- 0.000404075(MC stat) > PartialBRBR = 0.0139225 +- 0.00116947(stat) +- 0.000404075(MC stat) > PartialBRBR = 0.0139225 +- 0.00116947(stat) +- 0.000404075(MC stat) > PartialBRBR = 0.0126852 +- 0.00123447(stat) +- 0.000405462(MC stat) > PartialBRBR = 0.0119573 +- 0.00133944(stat) +- 0.000484691(MC stat) > PartialBRBR = 0.0110474 +- 0.00137170(stat) +- 0.000501760(MC stat) > PartialBRBR = 0.0112305 +- 0.00147592(stat) +- 0.000553075(MC stat) > PartialBRBR = 0.0100832 +- 0.00184243(stat) +- 0.000674057(MC stat) > PartialBRBR = 0.0121519 +- 0.00238772(stat) +- 0.000883651(MC stat) > > I would drop the last number and then the trend is lower partial BRBR > for purer samples. Both error sources increase with purer sample as > expected. So, what is the final figure of merit to choose a cut? Needs > to be discussed today. > > Cheers, > > Wolfgang > -- > ------------------------------------------------------------------------ > Wolfgang Menges > Queen Mary, University of London SLAC, MS 35 > Mile End Road 2575 Sand Hill Road > London, E1 4NS, UK Menlo Park, CA 94025, USA > +44 20 7882 3753 ++1 650 926 8503 > [log in to unmask] > ------------------------------------------------------------------------ >