Design of the Jet Performance Software for the ATLAS Experiment at LHC

This paper describes the design and implementation of the JetFramework, a software tool developed for the data analysis of the ATLAS experi- ment at CERN. JetFramework is based on Athena, an object oriented framework for data processing. The JetFramework Athena package im- plements a configurable data-flow graph (DFG) to represent an analysis. Each node of the graph can perform some computation on one or more particle collections in input. A standard set of nodes to retrieve, filter, sort and plot collections are provided. Users can also implement their own computation units inheriting from a generic interface. The analysis graph can be declared and configured in an Athena options file. To provide the requested flexibility to configure nodes from a configuration file, a sim- ple expression language permits to specify selection and plotting criterias. Viewing an analysis as an explicit DFG permits end-users to avoid writing code for repetitive tasks and to reuse user-defined computation units in other analysis.