BES Ⅲ 事例装配

1. BESⅢ事例装配 王亮亮 何康林

2. 物理事例模型 • EventList （Global event information ） totalTrks nChrg nNeu nVEEs (Ks, Lambda, gamma conversion ) nPi0 • DstTrkListCol DstTrkList trackID DstTofTrack DstMdcTrack DstEmcTrack DstMdcKalTrack DstMucTrack DstDedx DstExtTrack

3. 事例装配（径迹匹配） • 主要依据主漂仪室Track ID • MdcKalTrack • MdcTrack MdcDedx TofTrack • ExtTrack MucTrack • EMC • 根据外推径迹在EMC中的位置信息，寻找最近的shower，如果该最近shower的位置落在匹配窗口里，就算匹配上了。 • 目前匹配窗口是固定值，用户可通过jobOption文件修改 • 单根径迹匹配完成 • 完成该事例所有径迹匹配后，将一些统计信息填入 EventList (代码已完成，已经过初步运行测试)

4. Event : (psi->rho+pi) e.g.1 EventAssemblerAlg INFO Charged tracks:2 Ext track:2 Shower:4 Matched showers:2 EventAssemblerAlg INFO ******************** Track 0: ********************* EventAssemblerAlg INFO Mdc momentum:1.33205,-0.402469,-0.144816, EventAssemblerAlg INFO Ext Emc pos:927.287,-178.974,-101.103 EventAssemblerAlg INFO Emc rec pos:932.117,-147.996,-106.793 EventAssemblerAlg INFO ******************** Track 1: ********************* EventAssemblerAlg INFO Mdc momentum:-0.908757,-0.108897,-0.219115, EventAssemblerAlg INFO Ext Emc pos:-949.36,35.0157,-224.029 EventAssemblerAlg INFO Emc rec pos:-946.739,30.4099,-233.477 EventAssemblerAlg INFO ******************** Track 2: ********************* EventAssemblerAlg INFO Emc rec pos:-677.445,679.743,917.014 EventAssemblerAlg INFO ******************** Track 3: ********************* EventAssemblerAlg INFO Emc rec pos:-599.171,737.855,377.418

5. e.g. 2: EventAssemblerAlg INFO Charged tracks:2 Ext track:2 Shower:10 Matched shower:2 EventAssemblerAlg INFO ******************** Track 0: ********************* EventAssemblerAlg INFO Mdc momentum:1.38553,0.264665,-0.241138, EventAssemblerAlg INFO Ext Emc pos:907.677,270.601,-163.016 EventAssemblerAlg INFO Emc rec pos:899.936,288.234,-158.283 EventAssemblerAlg INFO ******************** Track 1: ********************* EventAssemblerAlg INFO Mdc momentum:-0.716237,-0.133478,-0.226759, EventAssemblerAlg INFO Ext Emc pos:-945.714,11.2047,-298.836 EventAssemblerAlg INFO Emc rec pos:-948.176,9.11283,-284.878 EventAssemblerAlg INFO ******************** Track 2: ********************* EventAssemblerAlg INFO Emc rec pos:-955.463,-97.3196,1019.57 EventAssemblerAlg INFO ******************** Track 3: ********************* EventAssemblerAlg INFO Emc rec pos:-928.328,-215.404,510.523 EventAssemblerAlg INFO ******************** Track 4: ********************* EventAssemblerAlg INFO Emc rec pos:831.404,444.927,5.24416 EventAssemblerAlg INFO ******************** Track 5: ********************* EventAssemblerAlg INFO Emc rec pos:831.935,445.229,-69.58 EventAssemblerAlg INFO ******************** Track 6: ********************* EventAssemblerAlg INFO Emc rec pos:915.038,224.73,-125.088 EventAssemblerAlg INFO ******************** Track 7: ********************* EventAssemblerAlg INFO Emc rec pos:-939.817,147.175,-411.326 EventAssemblerAlg INFO ******************** Track 8: ********************* EventAssemblerAlg INFO Emc rec pos:-944.408,129.738,-509.228 EventAssemblerAlg INFO ******************** Track 9: ********************* EventAssemblerAlg INFO Emc rec pos:625.254,-720.399,-577.885

6. psi->rho+pi • Ngood=2(|r0|<1mm,|z0|<5) • Ncharge=0 • nGama>=2 (E>0.04GeV,|deltaTheta|>20degree, |deltaPhi|>20degree) • 挑选来自pi0的两个光子： chi1=(Mgg-0.125)/0.1, chi2=(Etotal-3.0)/0.7 要求chi2=chi12+chi22最小 • |Mgg-0.125|<0.04GeV • |Etotal-3.0|<0.28GeV