JPS2006 @ Sheraton Waikiki Hotel Detector Optimization using Particle Flow Algorithm for ILC Contents 1. Introduction 2. Particle Flow Algorithm 3. Results 4. Summary DPF2006+JPS2006 @ Sheraton Waikiki Hotel Oct. 29th-Nov. 3rd, 2006 Tamaki Yoshioka ICEPP, Univ. of Tokyo On behalf of GLD Colleagues 10/31/2006 JPS2006 @ Sheraton Waikiki Hotel

JPS2006 @ Sheraton Waikiki Hotel Introduction Most of the important physics processes to be studied in the ILC experiment have multi-jets in the final state. → Jet energy resolution is the key in the ILC physics. The best energy resolution is obtained by reconstructing momenta of individual particles avoiding double counting among Trackers and Calorimeters. - Charged particles (~60%) measured by Tracker. - Photons (~30%) by electromagnetic CAL (ECAL). - Neutral hadrons (~10%) by ECAL + hadron CAL (HCAL). → Particle Flow Algorithm (PFA) In this talk, general scheme and performance of the GLD-PFA, using the GEANT4-based full simulator (Jupiter), will be presented. 10/31/2006 JPS2006 @ Sheraton Waikiki Hotel

JPS2006 @ Sheraton Waikiki Hotel GLD Detector Muon detector - One of the detector concepts for the ILC experiment. The world-wide consensus of the performance goal for the jet energy resolution is For more detail, please see the GLD Detector Outline Document (DOD) → physics/0607154 Calorimeter Coil Vertex detector Tracker GLD detector 10/31/2006 JPS2006 @ Sheraton Waikiki Hotel

JPS2006 @ Sheraton Waikiki Hotel GLD Detector Concept To get good energy resolution by PFA, separation of particles (reducing the density of charged and neutral particles at CAL surface) is important. Often quoted “Figure of Merit” B : Magnetic field R : CAL inner radius σ: CAL granularity RM : Effective Moliere length GLD concept 1. Large inner radius of ECAL to optimize the PFA. 2. Large tracker for excellent dpt/pt2 and pattern recognition. 3. Moderate B field (~3T). 10/31/2006 JPS2006 @ Sheraton Waikiki Hotel

GLD Geometry in Jupiter Solenoid TPC Hadron Calorimeter (HCAL) VTX, IT Muon Detector Electromagnetic Calorimeter (ECAL) Dodecagonal Shape As of October 06 10/31/2006 JPS2006 @ Sheraton Waikiki Hotel

Calorimeter Geometry in Jupiter Readout Line =10cm 349.4cm Barrel HCAL 229.8cm Barrel ECAL 210cm 270cm Endcap HCAL Barrel.InnerRadius=210cm Endcap ECAL Endcap.InnerRadius=40cm IP Barrel.HalfZ=280cm 419.4cm 280cm 299.8cm 10/31/2006 JPS2006 @ Sheraton Waikiki Hotel

Calorimeter Structure Active Layer Absorber Current cell size : 2x2cm Can be changed. ECAL W/Scinti./Gap 3/2/1 (mm) x 33 layers HCAL Fe/Scinti./Gap 20/5/1 (mm) x 46 layers 10/31/2006 JPS2006 @ Sheraton Waikiki Hotel

JPS2006 @ Sheraton Waikiki Hotel Z-pole Event Display End View Side View - Z → qq (uds) @ 91.2GeV, tile calorimeter, 2cm x 2cm tile size 10/31/2006 JPS2006 @ Sheraton Waikiki Hotel

Particle Flow Algorithm for GLD Flow of GLD-PFA Photon Finding Charged Hadron Finding Neutral Hadron Finding Satellite Hits Finding *Satellite hits = calorimeter hit cell which does not belong to a cluster core Note : Monte-Carlo truth information is used for muon and neutrino. 10/31/2006 JPS2006 @ Sheraton Waikiki Hotel

JPS2006 @ Sheraton Waikiki Hotel Photon Likelihood - Five variables are selected to form the photon likelihood function. Track Distance Velocity Mean Layer Photon Other Edep/Nhits chi2 Output Other Photon 10/31/2006 JPS2006 @ Sheraton Waikiki Hotel

Particle Flow Algorithm for GLD Flow of GLD-PFA Photon Finding Charged Hadron Finding Neutral Hadron Finding Satellite Hits Finding *Satellite hits = calorimeter hit cell which does not belong to a cluster core Note : Monte-Carlo truth information is used for muon and neutrino. 10/31/2006 JPS2006 @ Sheraton Waikiki Hotel

Charged Hadron Finding Basic Concept : Extrapolate a charged track and calculate a distance between a calorimeter hit cell and the extrapolated track. Connect the cell that in a certain tube radius (clustering). Extrapolated Track Calculate the distance for any track/calorimeter cell combination. HCAL Tube Radius Hit Cells Tube radius for ECAL and HCAL can be changed separately. distance ECAL Calorimeter input position Charged Track 10/31/2006 JPS2006 @ Sheraton Waikiki Hotel

Particle Flow Algorithm for GLD Flow of GLD-PFA Photon Finding Charged Hadron Finding Neutral Hadron Finding Satellite Hits Finding *Satellite hits = calorimeter hit cell which does not belong to a cluster core Note : Monte-Carlo truth information is used for muon and neutrino. 10/31/2006 JPS2006 @ Sheraton Waikiki Hotel

Neutral Hadron Likelihood - Four variables are selected to form the NHD likelihood function. Output Velocity Energy Density Satellite Hits Neutral Hadron Edep/Nhits Mean Layer Neutral Hadron Satellite Hits 10/31/2006 JPS2006 @ Sheraton Waikiki Hotel

Particle Flow Algorithm for GLD Flow of GLD-PFA Photon Finding Charged Hadron Finding Neutral Hadron Finding Satellite Hits Finding *Satellite hits = calorimeter hit cell which does not belong to a cluster core Note : Monte-Carlo truth information is used for muon and neutrino. 10/31/2006 JPS2006 @ Sheraton Waikiki Hotel

JPS2006 @ Sheraton Waikiki Hotel Event Display e+ e- Yellow : Photon Red, Green : Charged Hadron Black, Blue : Neutral Hadron Z → qqbar @ 91.2GeV 10/31/2006 JPS2006 @ Sheraton Waikiki Hotel Next: 電子、陽電子衝突

JPS2006 @ Sheraton Waikiki Hotel Event Display Yellow : Photon Red, Green : Charged Hadron Black, Blue : Neutral Hadron Gamma Finding 10/31/2006 JPS2006 @ Sheraton Waikiki Hotel

JPS2006 @ Sheraton Waikiki Hotel Event Display Yellow : Photon Red, Green : Charged Hadron Black, Blue : Neutral Hadron Charged Hadron Finding 10/31/2006 JPS2006 @ Sheraton Waikiki Hotel

JPS2006 @ Sheraton Waikiki Hotel Event Display Yellow : Photon Red, Green : Charged Hadron Black, Blue : Neutral Hadron Remove Satellite Hits 10/31/2006 JPS2006 @ Sheraton Waikiki Hotel

JPS2006 @ Sheraton Waikiki Hotel Event Display Yellow : Photon Red, Green : Charged Hadron Black, Blue : Neutral Hadron Remaining : Neutral Hadron 10/31/2006 JPS2006 @ Sheraton Waikiki Hotel

Jet Energy Resolution (Z-pole) - Z → uds @ 91.2GeV, tile calorimeter, 2cm x 2cm tile size All angle Almost no angular dependence : 31%/√E for |cosq|<0.9. cf. 60 %/√E w/o the PFA (sum up the calorimeter energy) 10/31/2006 JPS2006 @ Sheraton Waikiki Hotel

JPS2006 @ Sheraton Waikiki Hotel Performance - Energy-weighted Efficiency and Purity Definition Efficiency : xxx  (total xx E in collected hits)/(true xxx total E in CAL) Purity : Pxxx  (total xxx E in a cluster)/(total E in a cluster) xxx = Photon, CHD, NHD, Satellite both  and P values are energy-weighted 10/31/2006 JPS2006 @ Sheraton Waikiki Hotel

JPS2006 @ Sheraton Waikiki Hotel Jet Energy Resolution - Energy dependence of jet energy resolution. - Jet energy resolution linearly degrades. → Need to improve. 10/31/2006 JPS2006 @ Sheraton Waikiki Hotel

JPS2006 @ Sheraton Waikiki Hotel Summary • Realistic PFA has been developed using the GEANT-4 based full simulator of the GLD detector. • Jet energy resolution is studied by using Z→qq events. ILC goal of 30% has been achieved in the barrel region of the Z-pole events. • By using the PFA, we are going to optimize the detector parameters such as the calorimeter granularity, radius etc. 10/31/2006 JPS2006 @ Sheraton Waikiki Hotel