Full Simulation Session SuperB General Meeting EMC Full Simulation Full Simulation Session SuperB General Meeting Isola d’Elba 03/06/2010 S. Germani - C. Cecchi INFN Perugia & Perugia University

Outline Updates on Background Studies Clustering Optimization and Energy Resolution with Background Fwd PID material effect Conclusions and Outlook 03/06/2010 EMC FullSim Studies

Clustering From Nov. 09 Frascati Meeting No Clustering: Clustering : Ecrystal > 1 MeV Same as slac meetiong Clustering : Clustering algorithm as (supposed to be) in BaBar: Start from maximum energtyCrystal Look for crystal arount ME Xtal Sum crystal energy if E > digi threshold (0.2 - 0.5 MeV) If a Crystal around the ME one has E > seed threshold (2-3 MeV) look around it too Adapted for LSO 5 x 5 - 3 x 3 Matrix Take maximum energy crystal and a matrix of crystal arount it 100 MeV  1 GeV  From Nov. 09 Frascati Meeting 03/06/2010 EMC FullSim Studies

Particles per Integration Time Number of particles enetring the EMC volume: Direction Selection Outward bound cossing Inner Surface Inward bound crossing Outer Surface Particle Selection  e : E > 20 MeV n : all 03/06/2010 EMC FullSim Studies

Cluster Mc Match (QED Emin = Eseed) Almost half clusters Seem to be associated with neutrons Integartion Time 0.02 Cluster/BC x 200 BC ~ 4 Cluster << 40 Large differnce between neutrons And gammas Bunch Crossing 03/06/2010 EMC FullSim Studies

Cluster Particle Matching EMC Volume Boundary Cluster particle match performed choosing the Track with the smaller distance from the Cluster BARREL Fwd 03/06/2010 EMC FullSim Studies

Background Cluster Example Follow the avolution of background cluster with the number of bunc crossings Cluster Energy First Seed Crystal Energy Cluster Size Distance prom original Position Particle association Most of Background Clusters come form Overlapping of small energy deposits Partcle association is not meaningful 03/06/2010 EMC FullSim Studies

Clustering News Checking again what BaBar Clustering algorithm is supposed to be I found an addictional cut : The crystal with the maximum energy in the cluster should have Emax>10 MeV 03/06/2010 EMC FullSim Studies

Signal + Background Private production of single photons with Bruno Mix with RadBhabha events from February production Sum all energy deposits in a given Time Windows Perform clustering Usually several clusters from background Assign cluster to the Signal Photon 03/06/2010 EMC FullSim Studies

Time Window Width 100 MeV 500 MeV For large windows resolution and distribution shape entirely dominated by background 1 GeV From Now On Time Window = 300 ns 03/06/2010 EMC FullSim Studies

Distribution Fit Crystal Ball Novosibirsk+Gauss Measured Energy distibution changes with Energies Some complex fit function tested Keep using Crystal Ball function 03/06/2010 EMC FullSim Studies

Clustering: Time Window Effect of Time Window Width on Energy resolution Barrel Fwd Fit to be Checkd! Fit to be Checkd! Distribution shape changes widely with time window width Need to perform less automated fit procedure 03/06/2010 EMC FullSim Studies

Clustering: Time Window 2 Effect of Time Window Width on the number of extra cluster and anglular resolutuion Number of Clusters Theta Resolution 03/06/2010 EMC FullSim Studies

Clustering: Emax Energy Resolution Number of Clusters Effect of Cut energy for crystal with amximum energy in the cluster on Energy Resolution and Number of Clusters Energy Resolution Number of Clusters 03/06/2010 EMC FullSim Studies

Clustering: Eseed Barrel Fwd Effect of Seed energy threshold on Energy resolution Barrel Fwd 03/06/2010 EMC FullSim Studies

Clustering: Eseed 2 Barrel Theta Resolution Number of Clusters Effect of Seed Threshold Energy Number of Clusters Fwd Theta Resolution 03/06/2010 EMC FullSim Studies

Clustering: Edigi Barrel Fwd Effect of Minimum Crystal Energy Threshold on Energy Resolution Barrel Fwd 03/06/2010 EMC FullSim Studies

Clustering: Edigi 2 Number of Clusters Theta Resolution (Barrel) Effect of Minimum Crystal Energy Threshold On Angular Resolution and Number of Clusters Number of Clusters Theta Resolution (Barrel) 03/06/2010 EMC FullSim Studies

Fwd PID Thickness Current default Bruno geometry has 12 mm Quartz Fwd TOF (~10% X0) Modify thickness : 0, 5, 10, 15, 25 % X0 03/06/2010 EMC FullSim Studies

PID Thickness Effect on σE 100 ns Time Window 300 ns Time Window 12 mm Quartz (Bruno default) 12 mm Quartz (Bruno default) 03/06/2010 EMC FullSim Studies

Conclusions and Outlook Background has not negligible effect on reconstructed energy distribution Clustering optimization has an impact on the resolution and on the number of clusters Emax cut affects heavily the number of clusters Fwd PID material up to 25% X0 has a small effect on Energy resolution with present background level Time window width has a dominant effect at all energies Readout chain simulation need to be more realistic Interplay between Time Window Light Yield and Performance Time resolution to exclude extra background clusters Energy deposit storage in time slices may be needed for EMC 03/06/2010 EMC FullSim Studies