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EM scale using h ’s. Vishnu V. Zutshi BNL. Preamble. gg decays Important for absolute calibration Non-linearity and offsets Maybe possible with little or no trigger Maybe possible with little or no tracking Affords the possibility of refinement Testing ground for Monte Carlo.
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EM scale using h’s Vishnu V. Zutshi BNL
Preamble • gg decays • Important for absolute calibration • Non-linearity and offsets • Maybe possible with little or no trigger • Maybe possible with little or no tracking • Affords the possibility of refinement • Testing ground for Monte Carlo
Schematic • 2 peaks and a valley • EM3 is your best chance here • Neighbourhood definition • You may or may not want to extend the EM3 clustering to other floors • CellNN does extend it to other floors
CellNN • Each local maxima starts a floor cluster • An EM cell is defined to have 4 neighbours • Log weighting for position determination • Sharing based on a transverse parameterization of the shower • Angular matching between floor clusters • Position measurement is key
5 GeV h’s Asym=abs(e1-e2)/(e1+e2)
5 GeV h’s uncorrected corrected
5 GeV h’s + E corr. + Asym. cut
Lower Fcluster threshold 5 GeV h’s
Lower Fcluster threshold 5 GeV h’s
10 GeV h’s Energy matching E/Egen
10 GeV h’s uncorrected corrected E/Egen
10 GeV h’s deltaR=sqrt(df2+dh2)
Lower Fcluster threshold 5 GeV h’s
10 GeV h’s Position determined from ly3 if emfr>0.2
10 GeV h’s Ly3frac>0.2 and new W0’s
Ongoing… • W0’s for Fclustering • Energy corrections • Fthreshold • Neighbourhood • Sharing • Symmetric mass