1 //--------------------------------------------------------------------------
4 // This software is part of the EvtGen package developed jointly
5 // for the BaBar and CLEO collaborations. If you use all or part
6 // of it, please give an appropriate acknowledgement.
8 // Copyright Information: See EvtGen/COPYRIGHT
9 // Copyright (C) 1998 Caltech, UCSB
13 // Description: B ==> tau + nu
15 // Modification history:
17 // RYD/SHY April 23, 1997 Module created
19 //------------------------------------------------------------------------
21 #include "EvtGenBase/EvtPatches.hh"
25 #include "EvtGenBase/EvtParticle.hh"
26 #include "EvtGenBase/EvtPDL.hh"
27 #include "EvtGenBase/EvtGenKine.hh"
28 #include "EvtGenModels/EvtSLN.hh"
29 #include "EvtGenBase/EvtDiracSpinor.hh"
30 #include "EvtGenBase/EvtReport.hh"
31 #include "EvtGenBase/EvtVector4C.hh"
35 std::string EvtSLN::getName(){
41 EvtDecayBase* EvtSLN::clone(){
50 // check that there are 0 arguments
54 checkSpinParent(EvtSpinType::SCALAR);
56 checkSpinDaughter(0,EvtSpinType::DIRAC);
57 checkSpinDaughter(1,EvtSpinType::NEUTRINO);
62 void EvtSLN::initProbMax(){
64 double M=EvtPDL::getMeanMass(getParentId());
65 double m=EvtPDL::getMeanMass(getDaug(0));
67 double probMax=8.0*(M*M-m*m)*m*m;
74 void EvtSLN::decay(EvtParticle *p){
76 static EvtId EM=EvtPDL::getId("e-");
77 static EvtId MUM=EvtPDL::getId("mu-");
78 static EvtId TAUM=EvtPDL::getId("tau-");
80 p->initializePhaseSpace(getNDaug(),getDaugs());
87 p4_p.set(p->mass(),0.0,0.0,0.0);
91 if (getDaug(0)==TAUM || getDaug(0)==MUM || getDaug(0)==EM) {
92 l1=EvtLeptonVACurrent(l->spParent(0),nul->spParentNeutrino());
93 l2=EvtLeptonVACurrent(l->spParent(1),nul->spParentNeutrino());
96 l1=EvtLeptonVACurrent(nul->spParentNeutrino(),l->spParent(0));
97 l2=EvtLeptonVACurrent(nul->spParentNeutrino(),l->spParent(1));