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
10 // Module: EvtSVPCP.cc
12 // Description: Routine to decay scalar -> vectors+photon
13 // including CP violation effects
15 // Modification history:
17 // Maurizio pierini Nov 11, 2003 Module created
19 //------------------------------------------------------------------------
21 #include "EvtGenBase/EvtPatches.hh"
23 #include "EvtGenBase/EvtParticle.hh"
24 #include "EvtGenBase/EvtGenKine.hh"
25 #include "EvtGenBase/EvtPDL.hh"
26 #include "EvtGenBase/EvtVector4R.hh"
27 #include "EvtGenBase/EvtVector4C.hh"
28 #include "EvtGenBase/EvtTensor4C.hh"
29 #include "EvtGenBase/EvtTensor3C.hh"
30 #include "EvtGenBase/EvtReport.hh"
31 #include "EvtGenBase/EvtComplex.hh"
32 #include "EvtGenModels/EvtSVPCP.hh"
33 #include "EvtGenBase/EvtId.hh"
34 #include "EvtGenBase/EvtCPUtil.hh"
36 #include "EvtGenBase/EvtConst.hh"
38 EvtSVPCP::~EvtSVPCP() {}
40 std::string EvtSVPCP::getName(){
47 EvtDecayBase* EvtSVPCP::clone(){
53 void EvtSVPCP::initProbMax(){
55 setProbMax(2*(getArg(3)*getArg(3)+getArg(5)*getArg(5)));
60 void EvtSVPCP::init(){
62 // check that there are 7 arguments
66 checkSpinParent(EvtSpinType::SCALAR);
68 checkSpinDaughter(0,EvtSpinType::VECTOR);
69 checkSpinDaughter(1,EvtSpinType::PHOTON);
73 void EvtSVPCP::decay( EvtParticle *p ){
75 static EvtId B0=EvtPDL::getId("B0");
76 static EvtId B0B=EvtPDL::getId("anti-B0");
81 EvtCPUtil::getInstance()->OtherB(p,t,other_b,0.5);
83 EvtComplex G1P,G1M, G1_T_even, G1_T_odd;
85 double norm = getArg(3)*getArg(3)+getArg(5)*getArg(5);
87 G1P=EvtComplex(getArg(3)*cos(getArg(4))/norm,getArg(3)*sin(getArg(4))/norm);
88 G1M=EvtComplex(getArg(5)*cos(getArg(6))/norm,getArg(5)*sin(getArg(6))/norm);
90 G1_T_even = (G1P+G1M)/sqrt(2.0);
91 G1_T_odd = (G1P-G1M)/sqrt(2.0);
93 EvtComplex lambda_km =EvtComplex(cos(-2*getArg(0)),sin(-2*getArg(0)));
95 double cdmt=cos(getArg(1)*t/(2*EvtConst::c));
96 double sdmt=sin(getArg(1)*t/(2*EvtConst::c));
98 EvtComplex cG1_T_even,cG1_T_odd;
101 cG1_T_even = G1_T_even*(cdmt+lambda_km*EvtComplex(0.0,getArg(2)*sdmt));
102 cG1_T_odd = G1_T_odd*(cdmt-lambda_km*EvtComplex(0.0,getArg(2)*sdmt));
105 cG1_T_even = G1_T_even*(cdmt+(1.0/lambda_km)*EvtComplex(0.0,getArg(2)*sdmt));
106 cG1_T_odd =-G1_T_odd*(cdmt-(1.0/lambda_km)*EvtComplex(0.0,getArg(2)*sdmt));
109 EvtComplex hp, hm, h0;
111 // This part is adopted from EvtSVVHel and since there is
112 // a photon that can not have helicity 0 this is put in by
113 // setting the h0 amplitude to 0.
114 hm=(cG1_T_even-cG1_T_odd)/sqrt(2.0);
115 hp=(cG1_T_even+cG1_T_odd)/sqrt(2.0);
116 h0=EvtComplex(0.0,0.0);
120 p->initializePhaseSpace(getNDaug(),getDaugs());
123 EvtVector4R momv1 = v1->getP4();
124 EvtVector4R momph = ph->getP4();
128 g.setdiag(1.0,-1.0,-1.0,-1.0);
132 v=momv1/momv1.d3mag();
133 vp=(momv1+momph)/(momv1+momph).mass();
135 d=((1.0/sqrt(3.0))*(h0-(hp+hm))*(-1.0/sqrt(3.0)))*g+
136 ((1.0/sqrt(2.0))*(hp-hm)*EvtComplex(0.0,1.0)*(sqrt(1.0/2.0)))*dual(EvtGenFunctions::directProd(v,vp))+
137 (sqrt(2.0/3.0)*(h0+0.5*(hp+hm))*sqrt(3.0/2.0))*(EvtGenFunctions::directProd(v,v)+(1.0/3.0)*g);
139 EvtVector4C ep0,ep1,ep2;
141 ep0=d.cont1(v1->eps(0).conj());
142 ep1=d.cont1(v1->eps(1).conj());
143 ep2=d.cont1(v1->eps(2).conj());
145 EvtVector4C ep20,ep21,ep22;
147 ep20=ph->epsParentPhoton(0).conj();
148 ep21=ph->epsParentPhoton(1).conj();
150 vertex(0,0,ep0*ep20);
151 vertex(0,1,ep0*ep21);
153 vertex(1,0,ep1*ep20);
154 vertex(1,1,ep1*ep21);
156 vertex(2,0,ep2*ep20);
157 vertex(2,1,ep2*ep21);
164 std::string EvtSVPCP::getParamName(int i) {
171 return "finalStateCP";
185 std::string EvtSVPCP::getParamDefault(int i) {