MUC simulation and reconstruction Zhengyun YOU School of Physics , Peking University Jan 10th, 2006

Outline μ/π Identification; Muon Chamber structure; Muc Simulation; Muc Reconstruction; μ/π Identification; Summary;

Muon Chamber Structure Barrel + EndCap; RPC as μ detector; Barrel : 9 layers EndCap: 8 layers One dimension read-out strips;

Muc Simulation -- Geometry All muc detector info stored in gdml file, structure, geometry, materials… Muc gdml file GEANT4 Schema Converted to Geant4 represented geometry automatically by GDML Geant4 Schema; Detailed to each strip;

Muc Simulation -- Geometry All muc detector info stored in gdml file, structure, geometry, materials… Converted to Geant4 represented geometry automatically by GDML Geant4 Schema; Detailed to each strip;

Muc Simulation -- Digitization RPC Gas Chamber as sensitive detector and strips as readout; Project hits to nearby strips and set strips as fired; No TDC and ADC info, only the strip fired or not;

Muc Reconstruction -- Geometry GDML file (same as Simu) Muc geometry Initialization MucGeoGeneral MucGeoGap MucGeoStrip IMucGeomSvc ROOT Geometry Construct GDML-ROOT Schema MUC ROOT Volume Ptr Gap ROOT Strip ROOT :: Connect

Muc Reconstruction -- Algorithm Use Ext Track from Mdc as seed; Ext track Fired strips Window Searching hits gap by gap; Searching on Barrel first, then EndCap; Also Searching on neighboring segments; Line Fit with hits on track; Compare with Mc truth; Barrel End Cap

Muc Reconstruction -- Efficiency mu- cosθ(-0.9~0.9) 10,000 single mu- input event, In comparison with MC truth, Reconstruction efficiency is P (GeV/c) 0.5 0.75 1.0 Muc Reco Efficiency > 93.33% 98.43% 98.93% Num hits ~2 ~7 ~9

μ μ μ/π Identifcation π π 1.0GeV/c Input variables : 1. Depth of track in Iron ; 2. Max hits a layer contains; Algorithm ： Fisher (Linear); μ μ π π 1.0GeV/c

before entering Muc, limit Simple μ/π Identification Efficiency use Muc Info only % 91.2 90.3 μefficiency 87.6 18.9 12.6 15.0 π fake rate 6.24 Design Goal 9.0 12.0 6.0 9.0 5.5 GeV/c Ratio of π decay to μ before entering Muc, limit

Summary Muc simulation runs well in Boss5.0, Next stage will focus on digitization; Muc reconstruction also runs well, needs further study, especially on low momentum and combination of barrel and end cap. μ/π identification is just a simple model, much to do next.

Thank you!