VICOMTECH VISIT AT CERN CERN 2013, October 3 rd & 4 th O.COUET CERN/PH/SFT DATA VISUALIZATION IN HIGH ENERGY PHYSICS THE ROOT SYSTEM

HEP Software and Visualization Software in HEP can be divided in two main categories: –The “on-line” software dealing with the data acquisition and experiments monitoring in real time while the experiment is running. –The “off-line” software working on the simulated or real data stored on long term storage systems. Both are using visualization but in different ways. This presentation focuses mainly on the off-line software for which the most advanced visualization tools are required.

HEP software

Offline Software One can identify three main software activities in HEP “off-line” visualization computing: –Simulation –Events display –Data analysis and data presentation

Simulation Simulation packages (like GEANT4), describe the passage of elementary particles through matter.

Events display The primary goals of events display programs are the visual investigation and the understanding of the physics of complete events.

Data analysis and data presentation Statistical analysis, Data mining, Histograming

ROOT core software The ROOT framework provides the common ground software tools needed by the HEP experiments to store, analyze and visualize physics data. It is used by all the various kinds of software we have previously presented. Its main application field is data analysis and data presentation. ROOT is flexible enough to be used and adapted to any kind of data analysis task. For this, a programming/scripting interactive interface is essential (C++ interpreter).

Data Visualization in ROOT (1)

Data Visualization in ROOT (2)

Data Visualization in ROOT (3)

Event Display in ROOT: TEve package 3D is useful for a global aspect of event, but 2D projections give a more accurate view.