Mark Dorman UCL/RAL MINOS Collaboration Meeting Fermilab, Oct. 05 Data/MC Comparisons and Estimating the ND Flux with QE Events Update on QE event selection Data/MC comparisons for LE-10 beam Flux estimation methodology Preliminary results for ND flux Mark Dorman UCL/RAL MINOS Collaboration Meeting Fermilab, Oct. 05 Update on QE Event Selection I have switched to grouping my background PDFs (RES,DIS,NC) into a single PDF in each variable and bin of energy so as to have larger numbers of events and avoid any complicated normalizations. The PDFs now look as in the following examples: 2.0 2.5 GeV Mark Dorman UCL/RAL MINOS Collaboration Meeting Fermilab, Oct. 05 Update on QE Event Selection I have switched to grouping my background PDFs (RES,DIS,NC) into a single PDF in each variable and bin of energy so as to have larger numbers of events and avoid any complicated normalizations. The PDFs now look as in the following examples: 6.0 7.0 GeV Mark Dorman UCL/RAL MINOS Collaboration Meeting Fermilab, Oct. 05 Update on QE Event Selection I have switched to grouping my background PDFs (RES,DIS,NC) into a single PDF in each variable and bin of energy so as to have larger numbers of events and avoid any complicated normalizations. The PDFs now look as in the following examples: 10 12 GeV Mark Dorman UCL/RAL MINOS Collaboration Meeting Fermilab, Oct. 05 Update on QE Event Selection I have switched to grouping my background PDFs (RES,DIS,NC) into a single PDF in each variable and bin of energy so as to have larger numbers of events and avoid any complicated normalizations. The PDFs now look as in the following examples: 14 17 GeV Mark Dorman UCL/RAL MINOS Collaboration Meeting Fermilab, Oct. 05 Data and MC Files Used I have been working with R1.18 processed data and MC for the LE-10 beam and R1.18 processed 1/E flux MC. PDFs for the analysis were trained on a subset of the 1/E flux MC and the cuts to select QE-like events for each bin of energy were determined from a different subset of the 1/E flux MC. The data/MC comparisons and flux estimation have been performed using a large fraction of the LE-10 MC files available and LE-10 data (excluded runs where the beam config. variable was 0). Using standard beam quality cuts the POTs for data and MC were: Just under 15 times as much data as MC. All data/MC comparison plots have been normalized to the POTs of the MC. MC snarls x 2.4e13 POTs/snarl ~ 2.4e18 POTs Data (used TORTGT) ~ 3.4e19 POTs Mark Dorman UCL/RAL MINOS Collaboration Meeting Fermilab, Oct. 05 Efficiencies and Purities of QE-like Sample Selection removes: ~60% QE events ~91% RES events ~97% DIS events ~98% NC events Mark Dorman UCL/RAL MINOS Collaboration Meeting Fermilab, Oct. 05 Data/MC Comparisons Neutrino Energy Spectra MC is shifted to the right relative to data. Agreement good though. Mark Dorman UCL/RAL MINOS Collaboration Meeting Fermilab, Oct. 05 Data/MC Comparisons Other Energy Spectra Shift still visible in muon and shower energies. Mark Dorman UCL/RAL MINOS Collaboration Meeting Fermilab, Oct. 05 Data/MC Comparisons Assumed QE Events Black histogram is data events with energy reconstructed assuming the event is QE. Black points are data events with energies reconstructed as usual. Likewise for red MC histogram and points. Data and MC agree fairly well and also the neutrino energy spectra reconstructed with the assumption of a QE event agree well with the regularly reconstructed energies in both data and MC. This is what would be expected of a reasonably pure QE-like sample. Mark Dorman UCL/RAL MINOS Collaboration Meeting Fermilab, Oct. 05 Data/MC Comparisons q^2 Distributions Agree well. Mark Dorman UCL/RAL MINOS Collaboration Meeting Fermilab, Oct. 05 Data/MC Comparisons Low q^2 Suppression? MC is higher in the MeV region but the effect is not pronounced. I tried using a different QE selection that increased the QE purity in the few GeV region. I see a more pronounced effect in this sample. Mark Dorman UCL/RAL MINOS Collaboration Meeting Fermilab, Oct. 05 Data/MC Comparisons y Distributions Again the agreement is fairly good. Slight excess of y=0 events in MC. Mark Dorman UCL/RAL MINOS Collaboration Meeting Fermilab, Oct. 05 Flux Estimation Methodology For a given energy bin i: number of QE-like events = flux * ( QE xsec*QE efficiency + BG xsec*BG efficiency) From Neugen: = RES xsec*RES efficiency + DIS xsec*DIS efficiency + NC xsec*NC efficiency Get efficiencies from MC. Can't use NC xsec so use MC to estimate number of NC background events and subtract off. Mark Dorman UCL/RAL MINOS Collaboration Meeting Fermilab, Oct. 05 Flux Estimate The following is then an estimate of the shape of the flux: Next want to normalize to a MC flux based on the total cross section in the GeV region to put an absolute scale on this plot. Mark Dorman UCL/RAL MINOS Collaboration Meeting Fermilab, Oct. 05 Further Work There are some issues that need to be resolved... Am going to normalize my flux to a Gnumi flux that was produced using true neutrino energies and so must take account of events moving into different reconstructed neutrino energy bins (energy resolution for my events ~20%). Cannot completely decouple the NC background subtraction from the flux itself and this causes problems in the low energy bins where the NC events occupy a larger fraction of the total events in the sample. Need to redo the analysis with a harder cut to get the QE purity up and the background contributions down. Need more LE-10 MC to reduce the errors that come from estimating my QE, RES and DIS efficiencies/inefficiencies. Mark Dorman UCL/RAL MINOS Collaboration Meeting Fermilab, Oct. 05 Backup Slides Mark Dorman UCL/RAL MINOS Collaboration Meeting Fermilab, Oct. 05 Data/MC Comparisons q^2 Against Neutrino Energy