M.N Minard Calorimeter meeting 5-2-09

Calibration with 0

Work from Vanya

Gaël Rospabé Phd

M.N Minard Calorimeter meeting 5-2-09

Cluster selection

• Select 0 reconstructed from 2 separate Ecal clusters :

– Energy range of : 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 pairs within :– Average mass +- 2

http://lappwiki01.in2p3.fr/LHCB-LAPP/index.php/Ecal_Calibration#Calibration_algorithm

100kevts, MinBias, 900GeV

900GeV

M.N Minard Calorimeter meeting 5-2-09

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

M.N Minard Calorimeter meeting 5-2-09

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

70/100evts

S/B=5.2

14TeV

S/B = 3 0.80/100evts

14TeVNo tracking

M.N Minard Calorimeter meeting 5-2-09

Fisher for -id

Profils transverses : Seed, S4Ecal et ECl

Profils longitudinaux : PS et Hcal Impacts dans le SPD

Signal

Fond

M.N Minard Calorimeter meeting 5-2-09

14 TeV no tracking

Configuration N evts Temps

14TeVtrajectographe

5,4.108 75h

14TeV sansTrajectographe

1,8.109 250h

# 0 per cell depend upon the initial calibration dispersion

Data taking at 2kHz

After Fisher selection :

HLT independent 1% intercalibration reached

14 TeV - tracking

30 /100evtsS/B = 3

Worth waiting for tracking

M.N Minard Calorimeter meeting 5-2-09

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 )