"ROOT Turns 20" Users' Workshop

15-18 September 2015
Hotel Schweizerhof, Saas-Fee
Europe/Zurich timezone

Object oriented data analysis at the BGO–OD experiment

18 Sep 2015, 15:00
20m
Hotel Schweizerhof, Saas-Fee

Hotel Schweizerhof, Saas-Fee

Haltenstrasse 10 Saas-Fee
Presentation Presentations

Speaker

Oliver Freyermuth (Universitaet Bonn (DE))

Description

The BGO–OD experiment at the ELSA accelerator facility at Bonn is built for the systematic investigation of meson photoproduction in the GeV region. It uniquely combines a central, highly segmented BGO crystal calorimeter covering almost $4\pi$ in acceptance and a forward magnetic spectrometer complemented by time of flight walls. Object orientation is a requirement from the beginning to handle the diverse set of involved detectors. As a consequence, starting from the assembly of the event-based data during acquisition up to the level of physics analysis, ROOT-based datastructures are in heavy use. All analysis steps are performed with the framework ExPlORA based on ROOT which is optionally complemented by an event generator, Geant4, Geant-VMC, VGM and Genfit2 for monte carlo studies, geometry description and trackfitting. ExPlORA follows the principles of a plugin and container based data analysis. It offers both a consistent interface structure for plugin development in C++ and a versatile and performant XML-based configuration language which abstracts all steps from filtering the data up to the visualization with histograms or an event-display. The very portable analysis software can interface with several SQL databases, is subject to continuous testing and supports the developer with a large set of customized warnings facilitated by the reflection mechanisms offered by ROOT. Successive analysis and levels of data reduction are facilitated by making use of persistent references and a custom pruning procedure. The framework is complemented by a set of Qt-ROOT based applications for specialized simulations and data calibrations.

Primary author

Oliver Freyermuth (Universitaet Bonn (DE))