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) 1999 Caltech, UCSB
11 // Module: EvtSVVCPLH.cc
13 // Description: The decay of a scalar to two vector particles are
14 // performed with CP violation and different widths for
15 // the cpe even and od states. E.g. Bs->J/psi phi.
17 // Modification history:
19 // RYD November 5, 1999 Module created
21 //------------------------------------------------------------------------
23 #include "EvtGenBase/EvtPatches.hh"
25 #include "EvtGenBase/EvtParticle.hh"
26 #include "EvtGenBase/EvtGenKine.hh"
27 #include "EvtGenBase/EvtCPUtil.hh"
28 #include "EvtGenBase/EvtPDL.hh"
29 #include "EvtGenModels/EvtSVVHelAmp.hh"
30 #include "EvtGenBase/EvtReport.hh"
31 #include "EvtGenModels/EvtSVVCPLH.hh"
32 #include "EvtGenBase/EvtId.hh"
34 #include "EvtGenBase/EvtConst.hh"
37 EvtSVVCPLH::~EvtSVVCPLH() {}
39 std::string EvtSVVCPLH::getName(){
46 EvtDecayBase* EvtSVVCPLH::clone(){
48 return new EvtSVVCPLH;
52 void EvtSVVCPLH::init(){
54 // check that there are 9 arguments
58 checkSpinParent(EvtSpinType::SCALAR);
60 checkSpinDaughter(0,EvtSpinType::VECTOR);
61 checkSpinDaughter(1,EvtSpinType::VECTOR);
65 void EvtSVVCPLH::initProbMax(){
67 //This is probably not quite right, but it should do as a start...
70 setProbMax(2*(getArg(3)*getArg(3)+getArg(5)*getArg(5)+getArg(7)*getArg(7)));
74 void EvtSVVCPLH::decay( EvtParticle *p){
76 //added by Lange Jan4,2000
77 static EvtId BS0=EvtPDL::getId("B_s0");
78 static EvtId BSB=EvtPDL::getId("anti-B_s0");
83 EvtCPUtil::OtherB(p,t,other_b);
85 EvtComplex G0P,G1P,G1M;
87 G1P=EvtComplex(getArg(3)*cos(getArg(4)),getArg(3)*sin(getArg(4)));
88 G0P=EvtComplex(getArg(5)*cos(getArg(6)),getArg(5)*sin(getArg(6)));
89 G1M=EvtComplex(getArg(7)*cos(getArg(8)),getArg(7)*sin(getArg(8)));
91 EvtComplex lambda_km=EvtComplex(cos(2*getArg(0)),sin(2*getArg(0)));
93 double cdmt=cos(getArg(1)*t/(2*EvtConst::c));
94 double sdmt=sin(getArg(1)*t/(2*EvtConst::c));
96 EvtComplex cG0P,cG1P,cG1M;
98 static double ctauL=EvtPDL::getctau(EvtPDL::getId("B_s0L"));
99 static double ctauH=EvtPDL::getctau(EvtPDL::getId("B_s0H"));
101 //I'm not sure if the fabs() is right when t can be
102 //negative as in the case of Bs produced coherently.
104 double mt=exp(-fabs(t*(ctauL-ctauH)/(ctauL*ctauH)));
107 cG0P=pt*G0P*(cdmt+lambda_km*EvtComplex(0.0,getArg(2)*sdmt));
108 cG1P=pt*G1P*(cdmt+lambda_km*EvtComplex(0.0,getArg(2)*sdmt));
109 cG1M=mt*G1M*(cdmt-lambda_km*EvtComplex(0.0,getArg(2)*sdmt));
111 else if (other_b==BS0){
112 cG0P=pt*G0P*(cdmt+(1.0/lambda_km)*EvtComplex(0.0,getArg(2)*sdmt));
113 cG1P=pt*G1P*(cdmt+(1.0/lambda_km)*EvtComplex(0.0,getArg(2)*sdmt));
114 cG1M=-mt*G1M*(cdmt-(1.0/lambda_km)*EvtComplex(0.0,getArg(2)*sdmt));
117 report(ERROR,"EvtGen") << "other_b was not BSB or BS0!"<<endl;
124 AP=(cG1P+cG1M)/sqrt(2.0);
125 AM=(cG1P-cG1M)/sqrt(2.0);
127 EvtSVVHelAmp::SVVHel(p,_amp2,getDaug(0),getDaug(1),AP,A0,AM);