Gabriele Cosmo
81 lines
3.0 KiB
Plaintext
81 lines
3.0 KiB
Plaintext
$Id: README,v 1.6 2006/11/08 16:43:57 gunter Exp $
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-------------------------------------------------------------------
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=========================================================
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Geant4 - an Object-Oriented Toolkit for Simulation in HEP
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=========================================================
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ExampleN04
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----------
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ExampleN04 has a simplified collider detector geometry. This example
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demonstrates the following features.
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1. PYTHIA primary events.
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ExN04PrimaryGeneratorAction has G4HEPEvtInterface as the generator.
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G4HEPEvtInterface accesses to "pythia_event.data", which contains three
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events of Higgs generation produced by PYTHIA. "pythia_main.f" is an
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example FORTRAN code of PYTHIA for generating this event sample.
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2. Readout geometry
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ExN04DetectorConstruction defines a simplified collider detecor
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geometry, tracker made of cylindrical tubes, calorimeter made of
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cylindrical tubes, and muon trackers made of planes.
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Cylindrical calorimeter is made of tubes of lead and scintirator
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without cut in phi nor z direction. Energy deposition in scintirator
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is accumurated by ExN04CalorimeterSD sensitive detector, which has
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a readout geometry to find the phi-z cell.
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3. Physics processes
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The example uses the QGSP 'Educated guess physics list', which
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includes electro-magnetic and hadronic interactions.
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3.1 Compilation of the Hadronic Physics lists
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The compilation of the example N04 requires the previous compilation of
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the hadronic physics lists, they ARE automatically compiled together with
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the standard Geant4 libraries; you may disable building the physics lists
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by setting G4LIB_BUILD_LISTS to NO.
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If you try to compile the example without the lists, you might probably
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get an error message during the linking phase, similar to the following:
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"Linking exampleN04 ...
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/usr/bin/ld: cannot find -lQGSP"
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If they are not compiled, then you (or your Geant4 administrator)
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can do it with the following steps:
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a. Make sure the Geant4 environment variables G4LIB_BUILD_lists is NOT defined
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b. cd $G4INSTALL/source/physics_lists
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c. gmake
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4. Event filtering by the stacking mechanism.
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Higgs events in "pythia_event.data" have two lepton pairs produced
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by the Higgs decay via Z0. At the first stage of each event, only the
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primary muons are tracked without tracking secondaries. then the number
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of hits on the muon trackers are examined. At the next stage, only
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the primary charged particles are tracked only inside the barrel
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tracking area and the isolation of the primary muons are examined.
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At the third stage, all particles in the RoI (Region of Interest) along
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the isolated muons are tracked. All these examinations are applied in
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ExN04StackingAction.
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5. How to start
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- compile and link to generate an executable
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% cd N04
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% gmake
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- execute N04 in 'batch' mode from macro files
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% exampleN04 exampleN04.in
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- execute N04 in 'interactive mode' with visualization
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% exampleN04
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....
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Idle> type your commands. For instance:
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Idle> /run/beamOn 3
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....
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Idle> exit
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