# Presentation: 801914

##      Detector Design & Physics Simulation

- Data Analysis

- A high energy collision like the one shown above, observed by the DZERO detector at the Tevatron-Fermilab, involves the detection of thousands of tracks and energy depositions which need to be simulated from basic physics processes to tune the reconstruction programs and distinguish interesting events from background during data analysis.

- BaBar
- BOGUS
- (event display)

-      Detector Design & Physics Simulation

- Geant4 EM/Hadron shower
- (accessible by audience)

- Simulation programs play a fundamental role in optimizing the design of  detectors used in particle physics experiments. The election of the right materials, dimensions, and configurations with the aid of simulations is critical to optimize the detector performance and reduce costs. Simulation tools also help us to tune the programs used to identify and reconstruct particles from the information provided by the detector, typically voltages and electric charge. In the data analysis process, they teach us how to distinguish interesting physics collisions from background, by modeling the effects of the detector on the outgoing particles

- Taking into account the requirements of new HEP experiments with high complexity, a computer program named GEANT4 is developed by a world wide collaboration of more than 100 physicists and computer scientists associated with particle physics utilizing the most modern software engineering technologies. This software toolkit was designed to simulate particle interactions with matter. It allows to model in detail the geometry and materials of complex particle detectors, and propagate simulated particles in the presence of magnetic and electric fields.
- The GEANT4 users community have recently been expanded incorporating scientists from the space and medical application fields. GEANT4 is used in space research projects at ESA (European Space Agency) and NASA for estimating radiation doses of astronaut and semiconductor devices in ISS (International Space Station) and other space crafts. In the medical area, GEANT4 is helping to optimize  and redesign cancer treatments ranging from conventional photon-beam radiotherapy to brachytherapy, hadron therapy and boron capture therapy. Together with the World Wide Web, GEANT4 is one of the most successful examples of technology transfer from particle physics to the rest of society.

- Simulation tools: GEANT4

- The complexity of the detectors and the size of the data samples poses a challenge on the computer systems and simulation tools needed by modern experiments. For example, the BaBar experiment at SLAC PEP-II had already generated more than 500 million events and this number is continuously growing.
- At LHC (Large Hadron Collider) at CERN, the amount of simulated raw data needed by the CMS and ATLAS detectors is estimated to be the order of tens of Peta (1015) bytes. The large dimensions of the detector, the variety of materials utilized, the complexity of the physics processes involved, and the huge number of electronic channels of its read out system (millions) push the current computing and simulation tools to the limit and encourage new developments.

- Detector Simulation

- BOGUS (BaBar Object-oriented Geant4-based Unified Simulator) is simulating B0-B0bar events.

- Try to see how elementary particles interact with matter

- This interactive shower simulator is made of Geant4. You can specify  type and energy of primary particle and type of the material.