[807] | 1 | $Id: README,v 1.6 2006/11/08 16:43:57 gunter Exp $ |
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| 2 | ------------------------------------------------------------------- |
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| 3 | |
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| 4 | ========================================================= |
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| 5 | Geant4 - an Object-Oriented Toolkit for Simulation in HEP |
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| 6 | ========================================================= |
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| 7 | |
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| 8 | ExampleN04 |
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| 9 | ---------- |
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| 10 | |
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| 11 | ExampleN04 has a simplified collider detector geometry. This example |
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| 12 | demonstrates the following features. |
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| 13 | |
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| 14 | 1. PYTHIA primary events. |
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| 15 | |
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| 16 | ExN04PrimaryGeneratorAction has G4HEPEvtInterface as the generator. |
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| 17 | G4HEPEvtInterface accesses to "pythia_event.data", which contains three |
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| 18 | events of Higgs generation produced by PYTHIA. "pythia_main.f" is an |
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| 19 | example FORTRAN code of PYTHIA for generating this event sample. |
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| 20 | |
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| 21 | 2. Readout geometry |
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| 22 | |
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| 23 | ExN04DetectorConstruction defines a simplified collider detecor |
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| 24 | geometry, tracker made of cylindrical tubes, calorimeter made of |
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| 25 | cylindrical tubes, and muon trackers made of planes. |
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| 26 | Cylindrical calorimeter is made of tubes of lead and scintirator |
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| 27 | without cut in phi nor z direction. Energy deposition in scintirator |
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| 28 | is accumurated by ExN04CalorimeterSD sensitive detector, which has |
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| 29 | a readout geometry to find the phi-z cell. |
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| 30 | |
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| 31 | 3. Physics processes |
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| 32 | |
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| 33 | The example uses the QGSP 'Educated guess physics list', which |
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| 34 | includes electro-magnetic and hadronic interactions. |
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| 35 | |
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| 36 | 3.1 Compilation of the Hadronic Physics lists |
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| 37 | |
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| 38 | The compilation of the example N04 requires the previous compilation of |
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| 39 | the hadronic physics lists, they ARE automatically compiled together with |
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| 40 | the standard Geant4 libraries; you may disable building the physics lists |
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| 41 | by setting G4LIB_BUILD_LISTS to NO. |
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| 42 | If you try to compile the example without the lists, you might probably |
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| 43 | get an error message during the linking phase, similar to the following: |
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| 44 | "Linking exampleN04 ... |
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| 45 | /usr/bin/ld: cannot find -lQGSP" |
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| 46 | |
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| 47 | If they are not compiled, then you (or your Geant4 administrator) |
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| 48 | can do it with the following steps: |
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| 49 | a. Make sure the Geant4 environment variables G4LIB_BUILD_lists is NOT defined |
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| 50 | b. cd $G4INSTALL/source/physics_lists |
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| 51 | c. gmake |
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| 52 | |
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| 53 | 4. Event filtering by the stacking mechanism. |
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| 54 | |
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| 55 | Higgs events in "pythia_event.data" have two lepton pairs produced |
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| 56 | by the Higgs decay via Z0. At the first stage of each event, only the |
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| 57 | primary muons are tracked without tracking secondaries. then the number |
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| 58 | of hits on the muon trackers are examined. At the next stage, only |
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| 59 | the primary charged particles are tracked only inside the barrel |
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| 60 | tracking area and the isolation of the primary muons are examined. |
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| 61 | At the third stage, all particles in the RoI (Region of Interest) along |
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| 62 | the isolated muons are tracked. All these examinations are applied in |
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| 63 | ExN04StackingAction. |
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| 64 | |
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| 65 | 5. How to start |
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| 66 | |
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| 67 | - compile and link to generate an executable |
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| 68 | % cd N04 |
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| 69 | % gmake |
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| 70 | |
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| 71 | - execute N04 in 'batch' mode from macro files |
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| 72 | % exampleN04 exampleN04.in |
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| 73 | |
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| 74 | - execute N04 in 'interactive mode' with visualization |
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| 75 | % exampleN04 |
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| 76 | .... |
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| 77 | Idle> type your commands. For instance: |
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| 78 | Idle> /run/beamOn 3 |
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| 79 | .... |
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| 80 | Idle> exit |
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