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
11 // Module: EvtTauScalarnu.cc
13 // Description: The leptonic decay of the tau meson.
14 // E.g., tau- -> e- nueb nut
16 // Modification history:
18 // RYD January 17, 1997 Module created
20 //------------------------------------------------------------------------
22 #include "EvtGenBase/EvtPatches.hh"
26 #include "EvtGenBase/EvtParticle.hh"
27 #include "EvtGenBase/EvtPDL.hh"
28 #include "EvtGenBase/EvtGenKine.hh"
29 #include "EvtGenModels/EvtTauScalarnu.hh"
30 #include "EvtGenBase/EvtDiracSpinor.hh"
31 #include "EvtGenBase/EvtReport.hh"
32 #include "EvtGenBase/EvtVector4C.hh"
34 EvtTauScalarnu::~EvtTauScalarnu() {}
36 std::string EvtTauScalarnu::getName(){
43 EvtDecayBase* EvtTauScalarnu::clone(){
45 return new EvtTauScalarnu;
49 void EvtTauScalarnu::init(){
51 // check that there are 0 arguments
55 checkSpinParent(EvtSpinType::DIRAC);
57 checkSpinDaughter(0,EvtSpinType::SCALAR);
58 checkSpinDaughter(1,EvtSpinType::NEUTRINO);
62 void EvtTauScalarnu::initProbMax(){
68 void EvtTauScalarnu::decay(EvtParticle *p){
70 static EvtId TAUM=EvtPDL::getId("tau-");
71 p->initializePhaseSpace(getNDaug(),getDaugs());
75 EvtVector4R momscalar = p->getDaug(0)->getP4();
77 EvtVector4C tau1, tau2;
79 if (p->getId()==TAUM) {
80 tau1=EvtLeptonVACurrent(nut->spParentNeutrino(),p->sp(0));
81 tau2=EvtLeptonVACurrent(nut->spParentNeutrino(),p->sp(1));
84 tau1=EvtLeptonVACurrent(p->sp(0),nut->spParentNeutrino());
85 tau2=EvtLeptonVACurrent(p->sp(1),nut->spParentNeutrino());
88 vertex(0,tau1*momscalar);
89 vertex(1,tau2*momscalar);