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Hi all, as shown in my previous postings, we had two problems in PID: 1) the muon PID killing at Beta level seemed to be wrong. I observed large disagreements in p* distribution between data and MC. Once I re-applied the PID killing at recoilNtp level the situation was really improved. 2) the data showed large differences with respect to the old production in p* spectrum (both electrons and muons). More events at low p* were present. The same effect was present in Mx distributions (excess in data at high Mx). MC was pretty unchanged. Then I found an explanation to both the problems: 1) The problem in muons for MC is only in the vtight selector. Look at http://www.slac.stanford.edu/~daniele/testPID/m1000.eps this is the comparison between muon tight and verytight selectors for MC. As you see the vtight (histogram) has a lot of events at low momenta and this does not make sense. The vtight selector was the only selector that showed very strange behaviours. Probably this is caused by a wrong killing at Beta level and it should be investigated. BTW we used to apply tight selection for muons (no reason to use the vtight one). Then I think we can switch to tight one. 2) The differences in data-MC comparison are due to a wrong mes sideband subtraction. In the new data the purity is lower then before. The histogram based comparison (overall sideband subtraction) is not adequate. This is shown in the following table of comparison data-MC In http://www.slac.stanford.edu/BFROOT/www/Physics/Analysis/AWG/InclusiveSL/islrecoil/datagene0930_all/datagene0930_all-comp.html you can find the comparison based the overall comparison. Disagreement in pcms and mxhadfit plot is evident In http://www.slac.stanford.edu/BFROOT/www/Physics/Analysis/AWG/InclusiveSL/islrecoil/datagene0930_all_tree/datagene0930_all_tree-comp.html you see the same comparison on the same samples with the correct sideband subtraction bin by bin. All the effects are gone (except the mm2... sigh). Look in particular at the mxhadfit plot (before and after the lepton cut). The agreement is pretty good. Daniele p.s. The last QA plots (70fb-1 with muon tight selector) are in the web page usual page http://www.slac.stanford.edu/BFROOT/www/Physics/Analysis/AWG/InclusiveSL/islrecoil/QAcomparisons.html