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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