Event Reconstruction and Simulation in PandaRoot for the P̄ANDA Experiment

Abstract

The P̄ANDA experiment, which is currently under construction at the Facility for Antiproton and Ion Research (FAIR) in Darmstadt, Germany, will address fundamental questions in hadron and nuclear physics via interactions of antiprotons with nuclei. It will be installed at the High Energy Storage Ring (HESR), which will provide an antiproton beam with a momentum range of 1.5 - 15 GeV/c and a high average interaction rate on the fixed target of 2 × 107 events/s. The P̄ANDA experiment will adopt a continuous data acquisition and the expected data rate transmitted to a high-bandwidth computing network will be in the order of 200 GB/s. However, in order to be able to select many different and rare physics processes, an indiscriminate hardware trigger would not suffice. Instead, an online software-based data selection system will be used to select only relevant data and thereby reduce the data rate by a factor of up to 1000. Due to the high interaction rate a highly advanced online analysis must be developed to deal also with overlapping events. Scalability and parallelization of the reconstruction algorithms are therefore a particular focus in the development process. A simulation framework called PandaRoot is used to further optimize the detector performance and develop and evaluate different reconstruction algorithms for event building, tracking and particle identification. An overview about PandaRoot and the requirements on the event reconstruction algorithms is presented and algorithms for the event time reconstruction currently under development are discussed.