1 / 18

A Linear Collider Physics List for Geant4 Simulations

Victoria Linear Collider Workshop 28-31 July 2004 Dennis Wright (SLAC). A Linear Collider Physics List for Geant4 Simulations. Objectives. Provide a “standard” Geant4 physics list to be used in study of LC detectors Make the list easy to use and understand

gus
Télécharger la présentation

A Linear Collider Physics List for Geant4 Simulations

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Victoria Linear Collider Workshop 28-31 July 2004 Dennis Wright (SLAC) ALinear Collider Physics List for Geant4 Simulations

  2. Objectives • Provide a “standard” Geant4 physics list to be used in study of LC detectors • Make the list easy to use and understand • Keep it up-to-date as new models become available • Validate as test beam data becomes available • Include it in LC Geant4 example (Makoto Asai)

  3. Physics List Design • Forsimplicity: • Provide only one list everyone can use • Specializedlistscouldbeaddedlater • Avoid hadronic list libraries • Thesearenice,buttoogeneralandsomewhatinvolved • Write out a “long-hand” physics list • DerivedfromG4VModularPhysicsList • Everythingcontainedin12files • Easytoseewhatprocesses/modelsareusedandhowtheyareinvoked

  4. Physics List Contents (1) • Allapplicable standardEManddecayprocesses (as available in Geant4 6.2) • HadronprocessesandmodelstakenfromtheQGSP_BERThadronicphysicslist: • For incident (p, K, p, n) energies of ~20 GeV to 100 TeV: • (QGS) Quark Gluon String + PRE (Precompound) models • For all others (L, S, anti-p, ...) with energies 20 GeV to 100 TeV: • HEP (High Energy Parameterized model) • For all particles with energies between 9.5 GeV to 20 GeV: • LEP (Low Energy Parameterized model)

  5. Physics List Contents (2) • For incident p, p, n with energies < 10 GeV • Bertini cascade model • For all others (K, anti-n, ...) with energies < 10 GeV • LEP • At rest processes for p-, K- absorption, anti-p, anti-n annihilation • Neutron capture, neutron-induced fission • Elastic hadron-nucleus scattering (same model for all hadrons) • Added processes for light ions (d, t, 3He, a) • Elastic scattering • LEP model for inelastic (d, t, a)

  6. Justification of Model Choices:20 GeV and Above • Threemodelstochoosefrom: • HEP : works for all particles • QGS, FTF : work for p, K, p, n only • Use testbeam data to decide: • e/pratiofrom Atlas HEC prefers QGS, HEP • No data yet to say if QGS is better than HEP • Choose QGS because: • It is more thoroughly validated • It is based more on physics than parameterization • So use QGS for p, K, p, n, HEP for all others

  7. Fig.1 • F

  8. Fig. 2 • D

  9. Justification of Model Choices:Below 20 GeV • Between10and20GeV,onlyonemodelavailable: LEP • Below10GeV,threemodelstochoosefrom: • Low energy parameterized (LEP) : for all particles • Bertini cascade: for p, p, n only • Binary cascade: for p, p, n only • Pion production reactions clearly eliminate LEP • Bertini and Binary equally good, Bertini 8x faster • So LEP plus Bertini cascade required in list

  10. Fig. 3 • S

  11. Fig. 4 • W

  12. Plans • Add gamma- and electro-nuclear processes/models • Extend Bertini cascade to kaons • Add hadronic interactions for light ions (to replace LEP) • Validation gap: 1 – 15 GeV • Eagerly awaiting HARP publication • Looking for other test beam data in this range

  13. Maintenance and Use • Physics list will be maintained in FreeHEP CVS • Anyone can get it: • cvs -d :pserver:anonymous@cvs.freehep.org:/cvs/lcd LCPhys • Better models, bug fixes will be included as available • Questions, problems to • dwright@slac.stanford.edu

  14. Geant4 Highlights at Release 6.2 • RunManager • Now modularized, easier to embed in a framework • Event • Links between pre-assigned decay products and primary maintained • User information can be attached to event in G4VUserEventInformation (also track, vertex, particle and region) • Geometry • First steps taken to abstract navigator -> other, quite different steppers will soon be enabled • New default values for tracking in EM field -> improved accuracy • Divisions (ala Geant3) introduced

  15. Geant4 Highlights at Release 6.2 • Visualization • New HepRep XML driver for HepRep2 • New visualization commands • Remove obsolete OPACS driver • Environments • MOMO Java tools now included (geometry and physics editors) • Biasing • Importance, weight-window methods available • Co-works with scoring • EM processes • Example physics lists available

  16. Coming Highlights from Release 7.0 • “Unknown” particle class • Propagated in a field, through materials • Appears as a track/trajectory • Will decay if and only if pre-assigned decay channel is defined for that track • PDG compliance for particle numbers • Geometry • Mixing of placements and parameterized volumes • Twisted trapezoid shape • Reflection of parameterized volumes

  17. Coming Highlights from Release 7.0 • EM processes • Performanceanalysisandoptimizationofshowers • Hadronic processes • Revised physics lists based on new/updated models • NLD1 example • Demonstrates use of “unknown particle”, region user information, linking of primary particles, tracks, trajectories, hits • Includes physics list previously discussed • Currently available at http://www.slac.stanford.edu/~asai/NLD1/ • Will be extended example in release

More Related