// $Id: PndLLbarpol.C,v 1.3 2004/11/02 17:25:20 alex Exp $ // // M.Destefanis Jan 2004 // // Macro for the PANDA event generator. It samples the reaction // pbar(4.0 GeV/c) + p --> L Lbar // // modified by A.Galoyan { // load shared libraries gROOT->Reset(); gSystem->Load("libPhysics.so"); gSystem->Load("libEG.so"); gSystem->Load("lib/libPndJRGen.so"); gRandom.SetSeed(123456); //Lambda if (!(TDatabasePDG::Instance())->GetParticle(997)) (TDatabasePDG::Instance())->AddParticle("L -> p pi-","Title",1.115684,0,0.197/78900/1e9,0,"Unknown",997); Int_t array1[2]={2212,-211}; ((TDatabasePDG::Instance())->GetParticle(997))-> AddDecayChannel(1, 1.0, 2, array1); //Lambda bar if (!(TDatabasePDG::Instance())->GetParticle(998)) (TDatabasePDG::Instance())->AddParticle("L -> pbar pi+","Title",1.115684,0,0.197/78900/1e9,0,"Unknown",998); Int_t array2[2]={-2212,211}; ((TDatabasePDG::Instance())->GetParticle(998))-> AddDecayChannel(1, 1.0, 2, array2); if (!(TDatabasePDG::Instance())->GetParticle(999)) (TDatabasePDG::Instance())->AddParticle("BeamTarget","Title",4.0,0,4.0,0,"Unknown",999); Int_t array[2]={997,998}; ((TDatabasePDG::Instance())->GetParticle(999))-> AddDecayChannel(1, 1.0, 2, array); TLorentzVector Vertex, Beam, Target, s; Beam. SetXYZM(0.,0.,4.,((TDatabasePDG::Instance()) -> GetParticle(-2212)) -> Mass()); Target.SetXYZM(0.,0.,0.,((TDatabasePDG::Instance()) -> GetParticle( 2212)) -> Mass()); s = Beam+Target; cout << s.M() << endl; // mean location of the target //Vertex.SetXYZT(0,0,0,0); // zero by default // smearing of the primary vertex (Gauss with the above mean, and this sigma) //TVector3 VtxRes(.1,.1,.2); // what target smearing do you want??? TVector3 VtxRes(0,0,0); // what target smearing do you want??? TParticle BeamTarget(999,1,0,0,0,0,s,Vertex); PndReaction reaction( BeamTarget, VtxRes, "Gen_LLbarpol.root" ); reaction.SetDecayAsymmetry(997,1,1); reaction.SetPolarization(997,1,1); reaction.SetDecayAsymmetry(998,1,-1); reaction.SetPolarization(998,1,1); reaction.Loop(10005); }