Calibration with p 0

1. Calibration with p0 Work from Vanya Gaël Rospabé Phd Calorimeter meeting 5-2-09

2. 100kevts, MinBias, 900GeV Cluster selection • Select p0 reconstructed from 2 separate Ecal clusters : • Energy range of g : up to 5-8 GeV • No charge track within the Ecal cluster • Pt g >300Mev/c • On minimum biais events signal with low background : • Associate electromagnetic cluster within 80 cm • PS >10MeV • Select g pairs within : • Average mass +- 2 s http://lappwiki01.in2p3.fr/LHCB-LAPP/index.php/Ecal_Calibration#Calibration_algorithm 900GeV Calorimeter meeting 5-2-09

3. Calibration • Estimate the miscalibration • Select cell: Ecell >60% Ecluster • Fill correction factor histogram: • C = Mrec/mpi0 • N>200 evt • Calculate average • On the same events iterate . • To estimate : • Number of events / histogram • Number of iteration Calorimeter meeting 5-2-09

4. 70/100evts S/B=5.2 Does it work in all the cases? • No tracking 900GeV • All clusters are combined • Higher background • Select low multiplicity events • #Clusters <20 • 14 TeV with tracking 900 GeV No tracking S/B = 3 0.80/100evts 14TeV 14TeV No tracking Calorimeter meeting 5-2-09

5. Fond Fisher for g-id Profils longitudinaux : PS et Hcal Impacts dans le SPD Signal Profils transverses : Seed, S4Ecal et ECl Calorimeter meeting 5-2-09

6. 14 TeV no tracking • After Fisher selection : • HLT independent • 1% intercalibration reached 14 TeV - tracking 30 /100evts S/B = 3 Worth waiting for tracking • # 0 per cell depend upon the initial calibration dispersion • Data taking at 2kHz Calorimeter meeting 5-2-09

7. Tools available • Fisher tool : place or improvement .. • In absence of tracking , HCAL info reduce the combinatorial • Recalibration tools : • Selection • Correction average • Iteration • Stop procedure to improve. • http://lappwiki01.in2p3.fr/LHCB-LAPP/index.php/Ecal_Calibration#Calibration_algorithm • Gaël can be joined ( Annecy ) Calorimeter meeting 5-2-09