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da0e9ce3 | 1 | //-------------------------------------------------------------------------- |
2 | // | |
3 | // Environment: | |
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. | |
7 | // | |
8 | // Copyright Information: See EvtGen/COPYRIGHT | |
9 | // Copyright (C) 1998 Caltech, UCSB | |
10 | // | |
11 | // Module: EvtSLN.cc | |
12 | // | |
13 | // Description: B ==> tau + nu | |
14 | // | |
15 | // Modification history: | |
16 | // | |
17 | // RYD/SHY April 23, 1997 Module created | |
18 | // | |
19 | //------------------------------------------------------------------------ | |
20 | // | |
21 | #include "EvtGenBase/EvtPatches.hh" | |
22 | #include <stdlib.h> | |
23 | #include <iostream> | |
24 | #include <string> | |
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" | |
32 | ||
33 | EvtSLN::~EvtSLN() {} | |
34 | ||
35 | std::string EvtSLN::getName(){ | |
36 | ||
37 | return "SLN"; | |
38 | ||
39 | } | |
40 | ||
41 | EvtDecayBase* EvtSLN::clone(){ | |
42 | ||
43 | return new EvtSLN; | |
44 | ||
45 | } | |
46 | ||
47 | ||
48 | void EvtSLN::init(){ | |
49 | ||
50 | // check that there are 0 arguments | |
51 | checkNArg(0); | |
52 | checkNDaug(2); | |
53 | ||
54 | checkSpinParent(EvtSpinType::SCALAR); | |
55 | ||
56 | checkSpinDaughter(0,EvtSpinType::DIRAC); | |
57 | checkSpinDaughter(1,EvtSpinType::NEUTRINO); | |
58 | ||
59 | } | |
60 | ||
61 | ||
62 | void EvtSLN::initProbMax(){ | |
63 | ||
64 | double M=EvtPDL::getMeanMass(getParentId()); | |
65 | double m=EvtPDL::getMeanMass(getDaug(0)); | |
66 | ||
67 | double probMax=8.0*(M*M-m*m)*m*m; | |
68 | ||
69 | setProbMax(probMax); | |
70 | ||
71 | } | |
72 | ||
73 | ||
74 | void EvtSLN::decay(EvtParticle *p){ | |
75 | ||
76 | static EvtId EM=EvtPDL::getId("e-"); | |
77 | static EvtId MUM=EvtPDL::getId("mu-"); | |
78 | static EvtId TAUM=EvtPDL::getId("tau-"); | |
79 | ||
80 | p->initializePhaseSpace(getNDaug(),getDaugs()); | |
81 | ||
82 | EvtParticle *l, *nul; | |
83 | l= p->getDaug(0); | |
84 | nul= p->getDaug(1); | |
85 | ||
86 | EvtVector4R p4_p; | |
87 | p4_p.set(p->mass(),0.0,0.0,0.0); | |
88 | ||
89 | EvtVector4C l1, l2; | |
90 | ||
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()); | |
94 | } | |
95 | else{ | |
96 | l1=EvtLeptonVACurrent(nul->spParentNeutrino(),l->spParent(0)); | |
97 | l2=EvtLeptonVACurrent(nul->spParentNeutrino(),l->spParent(1)); | |
98 | } | |
99 | ||
100 | vertex(0,p4_p*l1); | |
101 | vertex(1,p4_p*l2); | |
102 | ||
103 | return; | |
104 | ||
105 | } | |
106 | ||
107 |