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Coordinators:
Rudi Frühwirth,
HEPHY Vienna |
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The track will introduce the fundamental concepts of Physics Computing and
will then address the central aspects of simulation and visualization,
including the simulation
of the experimental setup to optimize detectors, to test and improve
the reconstruction software, and to gain a detailed understanding of
the data. The first series of lectures gives an overview of the software and hardware components required for the processing of the experimental data, from the source - the detector - to the physics analysis. The emphasis is on the concepts, but some implementation details are discussed as well. The key concept is data reduction, both in terms of rate and in terms of information density. The various algorithms used for data reduction, both online and offline, are described. The flow of the real data is the main topic, but the need for and the production of simulated data is discussed as well. The second series of lectures
gives an introduction to the domain of simulating high energy physics
experiments with practical examples taken from the CERN/LHC based CMS
experiment. The lectures focus on event simulation based on the GEANT4
toolkit. GEANT4 is a toolkit for simulating the passage of particles
through matter. It includes a complete range of functionality including
tracking, geometry, physics models, and hits. The physics processes
offered cover a comprehensive range, including electromagnetic, hadronic
and optical processes, a large set of long-lived particles, materials
and elements, over a wide energy range starting, in some cases, from 250
eV and extending in others to the TeV energy range. It has been designed
and constructed to expose the physics models utilised, to handle complex
geometries, and to enable its easy adaptation for optimal use in
different sets of applications. These lectures will cover data analysis of simulated data using GEANT4, JAS3 and WIRED4 with an emphasis on rapidly developing simulations of prototype detectors. We will explain how to set up GEANT4 geometries using GDML (an XML markup developed specifically for GEANT4) how to visualize the resulting detectors and events using HepRep and WIRED4, and how to analyse the resulting data using JAS3. |
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Type |
Series |
Lecture |
Description |
Lecturer |
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Lectures |
General Introduction to Physics Computing |
Series |
General Introduction to Physics Computing The two lectures give an overview of the software and hardware components required for the processing of the experimental data, from the source - the detector - to the physics analysis. The emphasis is on the concepts, but some implementation details are discussed as well. The key concept is data reduction, both in terms of rate and in terms of information density. The various algorithms used for data reduction, both online and offline, are described. The flow of the real data is the main topic, but the need for and the production of simulated data is discussed as well. |
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Lecture 1 |
Lecture 1: Event filtering The first lecture deals with the multi-level event filters (triggers) that are used to select the physically interesting events and to bring down the event rate to an acceptable figure. Some examples of the hardware and software that is deployed by the LHC experiments are presented. |
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Lecture 2 |
Reconstruction and simulation The second lecture describes the various stages of event reconstruction, including calibration and alignment. The emphasis is on algorithms and data structures. The need for large amounts of simulated data is explained. The lecture concludes with a brief resume of the principles of physics analysis and the tools that are currently employed. |
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Lectures |
Introduction to Experiment simulation |
Lecture 1 |
Introduction to Experiment simulation This series of lectures gives an introduction to the domain of simulating high energy physics experiments with practical examples taken from the CERN/LHC based CMS experiment. The lectures focus on event simulation based on the GEANT4 toolkit. GEANT4 is a toolkit for simulating the passage of particles through matter. It includes a complete range of functionality including tracking, geometry, physics models, and hits. The physics processes offered cover a comprehensive range, including electromagnetic, hadronic and optical processes, a large set of long-lived particles, materials and elements, over a wide energy range starting, in some cases, from 250 eV and extending in others to the TeV energy range. It has been designed and constructed to expose the physics models utilised, to handle complex geometries, and to enable its easy adaptation for optimal use in different sets of applications. Basic simulation requirements are explained, such as experimental setup in terms of geometry, materials, and external electromagnetic fields, principles of physics processes, selection and configuration of physics processes, run and event concepts, and extraction of hit information. It is shown how this requirements are met by applying GEANT4. The programming language used throughout the lecture series is C++. |
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Exercises |
Introduction to Experiment simulation |
Exercise 1 |
Combined exercises on Experiment simulation and Data Analysis and Visualization Depending on their study backgrounds and personal interests, students will have the possibility to work on various exercises split into two topic sets aligned to the two lecture series:
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Lectures |
Data Analysis and Visualization using GEANT4, JAS3, and WIRED4 |
Lecture 1 |
Data Analysis and Visualization using GEANT4, JAS3, and WIRED4 These lectures will cover data analysis of simulated data using GEANT4, JAS3 and WIRED4 with an emphasis on rapidly developing simulations of prototype detectors. We will explain how to set up GEANT4 geometries using GDML (an XML markup developed specifically for GEANT4) how to visualize the resulting detectors and events using HepRep and WIRED4, and how to analyse the resulting data using JAS3. The lectures will introduce WIRED4 and JAS3. JAS3 is an experiment independent analysis toolkit which can be used to analyse data in a wide variety of different formats. We will demonstrate how to use JAS3 and AIDA, the underlying data analysis toolkit, for a variety of tasks including analysis of data produced by GEANT4. We will describe the structure of JAS3 and explain how developers can extend it by writing Java plugins. WIRED4 is a general purpose event display implemented as a plugin to JAS3. We will explain the major features such as user interactivity, special projections, data selection and cuts. We will cover how to generate events in the HepRep format used by WIRED from GEANT4 or other sources, and describe how users can extend the functionality of WIRED by writing their own plugins. Some familiarity with Java and XML will be useful but not required for understanding the lectures. |
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Exercises |
Experiment simulation and visualization (part 2) |
Exercise 1 |
Combined exercises on Experiment simulation and Data Analysis and Visualization Depending on their study backgrounds and personal interests, students will have the possibility to work on various exercises split into two topic sets aligned to the two lecture series:
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