21/09/2010CALICE Manqi RUAN Laboratoire Leprince-Ringuet (LLR) Ecole Polytechnique 91128, Palaiseau Status of DHCAL PFA Study

21/09/2010CALICE Outline ● Introduction ● SDHCAL Reco Soft Status ● Observation on PandoraPFA ● Preliminary studies ● Single Particle Event ● Tau jet level ● Summary and Plan

21/09/2010CALICE BKgrd ● JC Plot + Mark Plot to show leakage & confusion Vs energy

21/09/2010CALICE Reco Soft status ● DHCAL: finer granularity = less confusion ~ better performance ● PandoraPFA based reconstruction chain: ● Preliminary RPC digitization : to be upgraded with multiplicity effects → Ran's presentation ● PandoraPFA: learning phase -> optimize the parameters & orders of different modules ● DHCAL based algorithms: under development ● Kalman filter, Density & NN analysis, Hough transform... ● Dedicated clustering + Better hadronic shower energy estimator: to be developed and integrated ● Event Display: to be heavily employed to understand the performance

21/09/2010CALICE Pandora: learning phase ● Treating as black box: ● Pandora + Preliminary Digitization + Calibration constant tuning: ● Performance with uds evts: slightly Zthreshold, 360GeV PRELIMINARY

21/09/2010CALICE Step back to particle gun ● Simulated with mokka ● Pion, Klong: ● Statistic: 160k evts * (AHCAL + DHCAL) ● ( 2k * Energy (10, 20, GeV)*Polar angle (20, 30, 40,..., 90 Deg) ● Estimator: – Double counting probability (identify partial of the cluster as another PFO) – Probability of failure to link track to cluster (pion only) – Ratio of leading cluster hits number to total (digitized) hits number ● Tau event: low multiplicity jets: ● Visible energy resolution + confusion case analysis ● Chance...

21/09/2010CALICE Number of PFOs... ~ 90% of the event has only one reconstructed PFO; Barrel region seems slightly cleaner than Endcap; Evts with multiple PFO: pre interaction or cluster splitting

21/09/2010CALICE Total PFO Energy Vs Number of PFOs, 80 Deg Case with only 1 PFO: still have long tail... tracker not so reliable? 1 < Number of PFO < 5: larger estimated energy ~ double counting + pre interaction? Number of PFO > 10: pre interaction + confusion + cluster energy smearing

21/09/2010CALICE Single PFO case, 80 Deg Pion decay: 40GeV Pion ~ 12GeV neutrino + 28GeV muon... Evt 821, 40GeV Pion at MCTruth Identify as 46.6GeV PFO With 38GeV cluster Failure of track energy reconstruction?

21/09/2010CALICE Higher estimated energy at θ = 80Deg 4 PFOs, Identify as 100GeV Pion + 28GeV Neutron +... Total PFO energy = 130GeV (Evt 286) 2 PFOs, Identify as 100GeV Pion + 45GeV Neutron Total PFO energy = 145GeV Seed at deep ECAL Layer...

21/09/2010CALICE Higher estimated energy at θ = 80Deg (Evt 867) Simulation level Interaction at the TPC PFO level: 15PFOs Leading PFO with 54GeV cluster identified as 100GeV pion. Others contribute to double counted 32GeV... Tough case... interaction near the end of Tracker!

21/09/2010CALICE Even more crazy... Evt 646: Interaction Inside TPC Confused tracker: 3 LDCTrack found 6PFOs: 2 leading PFO assigned with tracks + cluster, with energy 110GeV (40GeV cluster) and 148GeV (55GeV cluster) Totally reconstructed energy: 264GeV Simulation level PFO level Flag on those kind of evts Relay more on cluster info?

21/09/2010CALICE “Lower” estimated energy at θ = 80Deg dude... you are a pion? Evt 346, Interaction at TPC entrance 18 PFOs, Total Energy 79GeV Simulation level

21/09/2010CALICE Total PFO Energy Vs Number of PFOs, 20 Deg Crazy single PFO events: pion decay + track energy resolution smearing N_PFO < 10: Linear dependence between N_PFO and total measured energy... ? Number of PFO > 10: pre interaction + confusion + cluster energy smearing, also the Calibration constant seems not optimized.

21/09/2010CALICE 20Deg polar angle Crazy track energy ~ 217GeV Cluster Energy = 87GeV 20Deg polar angle Total measured energy = 105GeV Higher estimated energy at θ = 20Deg Interaction in the Tracker

21/09/2010CALICE “Lower” estimated energy Pion decay: 42GeV neutrino + 58GeV muon... Theta = 20 deg Smearing of Track energy resolution Track energy = 91.2GeV Interaction before Calo + Cluster energy resolution uncertainty

21/09/2010CALICE DHCAL: Total PFO energy Most of the Event has nice energy resolution (from tracker) Higher estimated total PFO energy ~ Track energy resolution smearing (forward region) + double counting + interaction before Calo Lower estimated total PFO energy: Pion decay, interaction before calo, track energy smearing (forward), cluster energy smearing...

21/09/2010CALICE SDHCAL: Total Cluster Energy Resolution ~ 80%/sqrt(E) Similar behaviour in different polar angle ~1% - 2% event has very low clustered energy -> Pion Decay

21/09/2010CALICE Comparing with AHCAL: 80Deg SDHCAL, 10k evtsAHCAL, 20k evts No significant different at low polar angle.

21/09/2010CALICE 20Deg SDHCAL, 10k evtsAHCAL, 20k evts Nether at high polar angle...

21/09/2010CALICE 40Deg SDHCAL, 10k evtsAHCAL, 20k evts Nether at high polar angle...

21/09/2010CALICE Comparing with AHCAL Maybe slightly more double counting events (1 < NPFO < 5) for DHCAL... More PFOs in forward region comparing to Barrel

21/09/2010CALICE Summary on Pion case... ● SDHCAL and AHCAL have comparable performance on number of reconstructed particle for single pion event, with slightly more reconstructed PFO in DHCAL ● Significant more double counting in edge region: need better linking algorithm ● Higher estimated energy: ● For large polar angle: double counting + pre interaction and cluster energy resolution error ● For small polar angle: track energy resolution searing, double counting and pre interaction ● Lower estimated energy: ● Pion decay, pre interaction and energy resolution error. ● Interactions inside tracker region caused lots of uncertainty, our worst enemy??

21/09/2010CALICE Summary and Plans ● SDHCAL Reco software development is progressing in various directions; ● Pion, Klong conclusion ● Tau conclusion ● Looooooooooong to do list ● Identify man power ● Parameter & order optimization of PandoraPFA ● DHCAL energy estimator & clustering algorithm development ● Testing on benchmark physics processes with – Tau – ZZ, ZH – ttbar, SUSY events with multiple jet final state

21/09/2010CALICE DHCAL Pion evts Hadronic Shower is complex... Interaction before calo 100 GeV Pion, 20Deg polar angle; Total Measured PFO energy = 84.46GeV Not satisfactory but fine... Simulation level PFO level