+++ /dev/null
-//--------------------------------------------------------------------------
-//
-// Environment:
-// This software is part of the EvtGen package developed jointly
-// for the BaBar and CLEO collaborations. If you use all or part
-// of it, please give an appropriate acknowledgement.
-//
-// Copyright Information: See EvtGen/COPYRIGHT
-// Copyright (C) 1998 Caltech, UCSB
-//
-// Module: EvtSSSCPpng.cc
-//
-// Description: Routine to decay B -> 2 scalars taking into account penguin
-// contributions (assuming single quark dominance for penguins)
-//
-// Modification history:
-//
-// RYD/NK December 3, 1997 Module created
-//
-//------------------------------------------------------------------------
-//
-#include "EvtGenBase/EvtPatches.hh"
-#include <stdlib.h>
-#include "EvtGenBase/EvtParticle.hh"
-#include "EvtGenBase/EvtRandom.hh"
-#include "EvtGenBase/EvtGenKine.hh"
-#include "EvtGenBase/EvtCPUtil.hh"
-#include "EvtGenBase/EvtPDL.hh"
-#include "EvtGenBase/EvtReport.hh"
-#include "EvtGenModels/EvtSSSCPpng.hh"
-#include "EvtGenBase/EvtId.hh"
-#include <string>
-#include "EvtGenBase/EvtConst.hh"
-
-EvtSSSCPpng::~EvtSSSCPpng() {}
-
-std::string EvtSSSCPpng::getName(){
-
- return "SSS_CP_PNG";
-
-}
-
-
-EvtDecayBase* EvtSSSCPpng::clone(){
-
- return new EvtSSSCPpng;
-
-}
-
-void EvtSSSCPpng::init(){
-
- // check that there are 7 arguments
- checkNArg(7);
- checkNDaug(2);
-
- checkSpinParent(EvtSpinType::SCALAR);
-
- checkSpinDaughter(0,EvtSpinType::SCALAR);
- checkSpinDaughter(1,EvtSpinType::SCALAR);
-
-}
-
-void EvtSSSCPpng::initProbMax(){
-
- setProbMax(getArg(5)*getArg(5)*(1 + getArg(6)*getArg(6)));
-
-}
-
-void EvtSSSCPpng::decay( EvtParticle *p ){
-
- //added by Lange Jan4,2000
- static EvtId B0=EvtPDL::getId("B0");
- static EvtId B0B=EvtPDL::getId("anti-B0");
-
- double t;
- EvtId other_b;
-
- p->initializePhaseSpace(getNDaug(),getDaugs());
-
- EvtComplex amp;
-
- EvtComplex A,Abar;
- //EvtComplex ACC, AbarCC;
-
-// assume single (top) quark dominance for the penguin.
-
-// old: a0=alpha, a1=dm, a2=1, a3=1, a4=0, a5=1, a6=0
-// new: a0=beta, a1=gamma, a2=delta, a3=dm, a4=1, a5=1=A_{T}, a6=A_{P}/A_{T}
-
-// e.g., for B -> pi pi
-// A_{T} = |V_{ub} V_{ud}| T
-// A_{P} = |V_{tb} V_{td}| P
-// P and T are purely hadronic matrix elements
-// P/T = 0.055, A_{P}/A_{T} = 0.2 (see Marrocchesi and Paver, hep-ph/9702353)
-
-// A = A_{T}( exp(i(beta+gamma)) + (A_{P}/A_{T}) exp(i(delta))
-// A_bar = same, except for the sign of the weak phases
-// here, delta = delta_{p}-delta_{t} (rel. strong phase)
-
- A=getArg(5)*(EvtComplex(cos(-getArg(0)-getArg(1)),sin(-getArg(0)-getArg(1)))+getArg(6)*EvtComplex(cos(getArg(2)),sin(getArg(2))));
-
- Abar=getArg(5)*(EvtComplex(cos(getArg(0)+getArg(1)),sin(getArg(0)+getArg(1)))+getArg(6)*EvtComplex(cos(getArg(2)),sin(getArg(2))));
-
-// get fraction of B0 tags with these amplitudes
-
- //double xd = 0.65;
- double ratio = 1/(1 + 0.65*0.65);
-
- EvtComplex rf, rbarf;
-
- rf = EvtComplex(cos(2.0*getArg(0)),sin(2.0*getArg(0)))*Abar/A;
- rbarf = EvtComplex(1.0)/rf;
-
- double A2 = real(A)*real(A) + imag(A)*imag(A);
- double Abar2 = real(Abar)*real(Abar) + imag(Abar)*imag(Abar);
-
- double rf2 = real(rf)*real(rf) + imag(rf)*imag(rf);
- double rbarf2 = real(rbarf)*real(rbarf) + imag(rbarf)*imag(rbarf);
-
- //fraction of B0 _tags_
- double fract =(Abar2*(1+ rbarf2 + (1 - rbarf2)*ratio))/(Abar2*(1+ rbarf2 + (1 - rbarf2)*ratio) + A2*(1+ rf2 + (1 - rf2)*ratio));
-
- EvtCPUtil::getInstance()->OtherB(p,t,other_b,fract);
-
-//this method works just as well -- NK
-//randomly generate the tag (B0 or B0B)
-
-// double tag = EvtRandom::Flat(0.0,1.0);
-// if (tag < 0.5) {
-//
-// EvtCPUtil::OtherB(p,t,other_b,1.0);
-// other_b = B0;
-// }
-// else {
-//
-// EvtCPUtil::OtherB(p,t,other_b,0.0);
-// other_b = B0B;
-// }
-
-//mixing angle = -beta
-
- if (other_b==B0B){
- amp=A*cos(getArg(3)*t/(2*EvtConst::c))+
- EvtComplex(cos(2.0*getArg(0)),sin(2.0*getArg(0)))*
- getArg(4)*EvtComplex(0.0,1.0)*Abar*sin(getArg(3)*t/(2*EvtConst::c));
- }
- if (other_b==B0){
- amp=A*EvtComplex(cos(-2.0*getArg(0)),sin(-2.0*getArg(0)))*
- EvtComplex(0.0,1.0)*sin(getArg(3)*t/(2*EvtConst::c))+
- getArg(4)*Abar*cos(getArg(3)*t/(2*EvtConst::c));
- }
-
- vertex(amp);
-
- return ;
-}
-
-