Hi Kerstin, first I have some comments to your numbers, that you are not really comparing the correct things, but them I have some other numbers to confirm your findings. So, you can not take the numbers of events in the BSemiExcl data skim to calculate any ratios. The contain all data (well, mostly Bs but anyway). You have to run them through BbkLumi and use the luminosity or number of BB events, which is the same by a constant factor. And you are neglecting Run3, which might or might not affect the whole thing. Anyway, here are the numbers run by run: generic: 1235(all/BsemiExcl) 1237(all/BSemiExcl) total ratio 1235/1237 run1: 24246000 1667945 28762000 1814045 53008000 0.8429 run2: 119356000 8955315 120299826 7443054 239655826 0.9921 run3: 67974000 4742604 61310000 3914416 129284000 1.1087 run4: 332944433 27934200 336130399 24157489 669074832 0.9905 data: lumi B-counting AllEvents BSemiExcl run1: 19458.963 21181864 268587495 3982175 run2: 60266.741 66441247 866976254 12802202 run3: 31061.051 34076579 447426127 6688118 run4: 99762.620 110107681 1512711646 23104133 sum generic/2/data: (lumi) run1: 1.362 run2: 1.987 run3: 2.081 run4: 3.353 So, there are two things. There is a minor dependency in the ratio charged/neutrals by run period (~15%). There is a strong dependency in the ratio generic/data by run period. So, we should weight by different run period. It is possible to distinguish between run123 and run4 using the run number. I will see if this is also possible for run1, run2 and run3. How about reweighting between charged and neutral Bs? Could/will be more difficult. ;-) Cheers, Wolfgang Kerstin Tackmann wrote: > Hi, > > here are some more numbers along these lines... > > I had a closer look at the number of events in the generic MC we are > using. > > In the reduced ntuples (without any cuts, fits, ...) we have the following > numbers of entries in the TTree: > Run1+2 448821 > Run4 1196783 > > the ratio of these is 2.667 > > looking at Roberto's tcl files, I find these numbers (the numbers of > events we run over in production): > Run1-2 19880359 > Run4 52091689 > > and the ratio is 2.620. > > This looks to me as if our ratio of generic MC between SP5 and SP6 simply > does not match the ratio of luminosities in the corresponding runs in > data. I thought we are supposed to use SP5 and SP6 so that it corresponds > to the lumi ratios.... > > in data I see in the tcl files > Run1+2 16784377 > Run4 23104133 > > and the ratio is 1.377. > > > Are we not using all of the generic SP5? Or do we somehow use extra SP6? > How did this come about? Could someone (Roberto, Wolfgang, ?) please > clarify this? > > Kerstin > > > >> The interesting point is that the SP6/SP5 yield is different from >> the ratio of Run4/Run1+2 luminosities, take e.g. your Vcb 1'bin numbers: >> >> SP6/SP5 = 1327.69/482.67 = 2.75 >> Run4/Run1+2 = 100ifb/80ifb = 1.25 -- ------------------------------------------------------------------------ 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] ------------------------------------------------------------------------