Update of an Object Oriented Track Reconstruction Model for LHC Experiments

摘要

In this update report about an Object Oriented (OO) track reconstruction model,which was presented at CHEP'97,CHEP'98,and CHEP'2000,we shall describe subsequent new developments since the beginning of year 2000.The OO model for the Kalman filtering method has been designed for high energy physics experiments at high luminosity hadron colliders.It has been coded in the C++ programming language originally for the CMS experiment at the future Large Hadron Collider (LHC) at CERN,and later has been successfully implemented into three different OO computing environments(including the level-2 trigger and offline software systems)of the ATLAS(another major experiment at LHC).For the level-2 trigger software environment.we shall selectively present some latest performance results(e.g.the B-physics event selection for ATLAS level-2 trigger,the robustness study result,ets.).For the offline environment,we shall present a new 3-D space point package which provides the essential offline input.A major development after CHEP'2000 is the implementation of the OO model into the new OO software frameworkAthena"of ATLAS experiment.The new modularization of this OO package enables the model to be more flexible and to be more easily implemented into different software environments.Also it provides the potential to handle the more comlpicated realistic situation(e.g.to include the calibration correction and the alignment correction,etc.) Some general interface issues(e.g.design of the common track class)of the algorithms to different framework environments have been investigated by using this OO package.