Geant4 User's Guide for Application Developers - Geant4 - CERN

Tracking and PhysicsThis method returns the result of a check to see if the process is possible for a given particle.Example of how to use a hadron at rest processIncluding a ``hadron at rest'' process for a particle, a pi- for example, into the Geant4 system is straightforwardand can be done in the following way:• create a process:theProcess = new G4PionMinusAbsorptionAtRest();• register the process with the particle's process manager:theParticleDef = G4PionMinus::PionMinus();G4ProcessManager* pman = theParticleDef->GetProcessManager();pman->AddRestProcess( theProcess );5.2.2.3. Hadrons in FlightWhat processes do you need?For hadrons in motion, there are four physics process classes. Table 5.1 shows each process and the particles forwhich it is relevant.G4HadronElasticProcessG4HadronInelasticProcessG4HadronFissionProcessG4CaptureProcesspi+, pi-, K + , K 0 S, K 0 L, K - , p, p-bar, n, n-bar, lambda,lambda-bar, Sigma + , Sigma - , Sigma + -bar, Sigma - -bar,Xi 0 , Xi - , Xi 0 -bar, Xi - -barpi+, pi-, K + , K 0 S, K 0 L, K - , p, p-bar, n, n-bar, lambda,lambda-bar, Sigma + , Sigma - , Sigma + -bar, Sigma - -bar,Xi 0 , Xi - , Xi 0 -bar, Xi - -baralln, n-barTable 5.1. Hadronic processes and relevant particles.How to register ModelsTo register an inelastic process model for a particle, a proton for example, first get the pointer to the particle'sprocess manager:G4ParticleDefinition *theProton = G4Proton::ProtonDefinition();G4ProcessManager *theProtonProcMan = theProton->GetProcessManager();Create an instance of the particle's inelastic process:G4ProtonInelasticProcess *theProtonIEProc = new G4ProtonInelasticProcess();Create an instance of the model which determines the secondaries produced in the interaction, and calculates themomenta of the particles:G4LEProtonInelastic *theProtonIE = new G4LEProtonInelastic();Register the model with the particle's inelastic process:theProtonIEProc->RegisterMe( theProtonIE );Finally, add the particle's inelastic process to the list of discrete processes:161