EvtSSDCP Class Reference

#include <EvtSSDCP.hh>

Inheritance diagram for EvtSSDCP:

Public Member Functions
	EvtSSDCP ()
virtual	~EvtSSDCP ()
void	getName (std::string &name)
EvtDecayBase *	clone ()
void	initProbMax ()
void	init ()
void	decay (EvtParticle *p)
Public Member Functions inherited from EvtDecayAmp
void	makeDecay (EvtParticle *p)
void	setWeight (double weight)
void	vertex (const EvtComplex &amp)
void	vertex (int i1, const EvtComplex &amp)
void	vertex (int i1, int i2, const EvtComplex &amp)
void	vertex (int i1, int i2, int i3, const EvtComplex &amp)
void	vertex (int *i1, const EvtComplex &amp)
virtual	~EvtDecayAmp ()
Public Member Functions inherited from EvtDecayBase
virtual std::string	commandName ()
virtual void	command (std::string cmd)
double	getProbMax (double prob)
double	resetProbMax (double prob)
	EvtDecayBase ()
virtual	~EvtDecayBase ()
virtual bool	matchingDecay (const EvtDecayBase &other) const
EvtId	getParentId ()
double	getBranchingFraction ()
void	disableCheckQ ()
void	checkQ ()
int	getNDaug ()
EvtId *	getDaugs ()
EvtId	getDaug (int i)
int	getNArg ()
int	getPHOTOS ()
void	setPHOTOS ()
void	setVerbose ()
void	setSummary ()
double *	getArgs ()
std::string *	getArgsStr ()
double	getArg (int j)
std::string	getArgStr (int j)
std::string	getModelName ()
int	getDSum ()
int	summary ()
int	verbose ()
void	saveDecayInfo (EvtId ipar, int ndaug, EvtId *daug, int narg, std::vector< std::string > &args, std::string name, double brfr)
void	printSummary ()
void	setProbMax (double prbmx)
void	noProbMax ()
void	checkNArg (int a1, int a2=-1, int a3=-1, int a4=-1)
void	checkNDaug (int d1, int d2=-1)
void	checkSpinParent (EvtSpinType::spintype sp)
void	checkSpinDaughter (int d1, EvtSpinType::spintype sp)
virtual int	nRealDaughters ()

Additional Inherited Members
Static Public Member Functions inherited from EvtDecayBase
static void	findMasses (EvtParticle *p, int ndaugs, EvtId daugs[10], double masses[10])
static void	findMass (EvtParticle *p)
static double	findMaxMass (EvtParticle *p)
Protected Member Functions inherited from EvtDecayBase
bool	daugsDecayedByParentModel ()
Protected Attributes inherited from EvtDecayAmp
EvtAmp	_amp2
Protected Attributes inherited from EvtDecayBase
bool	_daugsDecayedByParentModel

Detailed Description

Definition at line 30 of file EvtSSDCP.hh.

Constructor & Destructor Documentation

EvtSSDCP()

EvtSSDCP::EvtSSDCP ( )

inline

Definition at line 34 of file EvtSSDCP.hh.

{}

Referenced by clone().

~EvtSSDCP()

EvtSSDCP::~EvtSSDCP ( )

virtual

Definition at line 36 of file EvtSSDCP.cc.

{}

Member Function Documentation

clone()

EvtDecayBase * EvtSSDCP::clone ( )

virtual

Implements EvtDecayBase.

Definition at line 45 of file EvtSSDCP.cc.

                             {
 
  return new EvtSSDCP;
 
}

decay()

void EvtSSDCP::decay ( EvtParticle * p )

virtual

Implements EvtDecayBase.

Definition at line 168 of file EvtSSDCP.cc.

                                   {
 
  static EvtId B0=EvtPDL::getId("B0");
  static EvtId B0B=EvtPDL::getId("anti-B0");
  
  double t;
  EvtId other_b;
  EvtId daugs[2];
 
  int flip=0;
  if (!_eigenstate){
    if (EvtRandom::Flat(0.0,1.0)<0.5) flip=1;
  }
 
  if (!flip) {
    daugs[0]=getDaug(0);
    daugs[1]=getDaug(1);
  }
  else{
    daugs[0]=EvtPDL::chargeConj(getDaug(0));
    daugs[1]=EvtPDL::chargeConj(getDaug(1));
  }
 
  EvtParticle *d;
  p->initializePhaseSpace(2, daugs);
 
  EvtComplex amp;
 
 
  EvtCPUtil::OtherB(p,t,other_b,0.5); // t is c*Dt (mm)
 
  //if (flip) t=-t;
 
  //FS We assume DGamma=GammaLow-GammaHeavy and Dm=mHeavy-mLow
  EvtComplex expL=exp(-EvtComplex(-0.25*_dgamma*t,0.5*_dm*t));
  EvtComplex expH=exp(EvtComplex(-0.25*_dgamma*t,0.5*_dm*t));
  //FS Definition of gp and gm
  EvtComplex gp=0.5*(expL+expH);
  EvtComplex gm=0.5*(expL-expH);
  //FS Calculation os sqrt(1-z^2) 
  EvtComplex sqz=sqrt(abs(1-_z*_z))*exp(EvtComplex(0,arg(1-_z*_z)/2));
  
  //EvtComplex BB=0.5*(expL+expH);                  // <B0|B0(t)>
  //EvtComplex barBB=_qoverp*0.5*(expL-expH);       // <B0bar|B0(t)>
  //EvtComplex BbarB=_poverq*0.5*(expL-expH);       // <B0|B0bar(t)>
  //EvtComplex barBbarB=BB;                         // <B0bar|B0bar(t)>
  //  FS redefinition of these guys... (See BAD #188 eq.35 for ref.)
  //  q/p is taken as in the BaBar Phys. Book (opposite sign wrt ref.)
  EvtComplex BB=gp+_z*gm;                 // <B0|B0(t)>
  EvtComplex barBB=sqz*_qoverp*gm;       // <B0bar|B0(t)>
  EvtComplex BbarB=sqz*_poverq*gm;       // <B0|B0bar(t)>
  EvtComplex barBbarB=gp-_z*gm;           // <B0bar|B0bar(t)>
 
  if (!flip){
    if (other_b==B0B){
      //at t=0 we have a B0
      //report(INFO,"EvtGen") << "B0B"<<endl;
      amp=BB*_A_f+BbarB*_Abar_f;
      //std::cout << "noflip B0B tag:"<<amp<<std::endl;
      //amp=0.0;
    }
    if (other_b==B0){
      //report(INFO,"EvtGen") << "B0"<<endl;
      amp=barBB*_A_f+barBbarB*_Abar_f;
    }
  }else{
    if (other_b==B0){
      amp=barBB*_A_fbar+barBbarB*_Abar_fbar;
      //std::cout << "flip B0 tag:"<<amp<<std::endl;
      //amp=0.0;
    }
    if (other_b==B0B){
      amp=BB*_A_fbar+BbarB*_Abar_fbar;
    }
  }
 
 
  EvtVector4R p4_parent=p->getP4Restframe();
  double m_parent=p4_parent.mass();
 
  EvtSpinType::spintype d2type=EvtPDL::getSpinType(getDaug(1));
 
  EvtVector4R momv;
  EvtVector4R moms;
 
  if (d2type==EvtSpinType::SCALAR){
    d2type=EvtPDL::getSpinType(getDaug(0));
    d= p->getDaug(0);
    momv = d->getP4();
    moms = p->getDaug(1)->getP4();
  }
  else{
    d= p->getDaug(1);
    momv = d->getP4();
    moms = p->getDaug(0)->getP4();
  }
 
 
 
  if (d2type==EvtSpinType::SCALAR) {
    vertex(amp);
  }
  
  if (d2type==EvtSpinType::VECTOR) {
    
    double norm=momv.mass()/(momv.d3mag()*p->mass());
    
    vertex(0,amp*norm*p4_parent*(d->epsParent(0)));
    vertex(1,amp*norm*p4_parent*(d->epsParent(1)));
    vertex(2,amp*norm*p4_parent*(d->epsParent(2)));
  
  }
 
  if (d2type==EvtSpinType::TENSOR) {
 
    double norm=d->mass()*d->mass()/(m_parent*d->getP4().d3mag()*d->getP4().d3mag());
 
   
   vertex(0,amp*norm*d->epsTensorParent(0).cont1(p4_parent)*p4_parent);
   vertex(1,amp*norm*d->epsTensorParent(1).cont1(p4_parent)*p4_parent);
   vertex(2,amp*norm*d->epsTensorParent(2).cont1(p4_parent)*p4_parent);
   vertex(3,amp*norm*d->epsTensorParent(3).cont1(p4_parent)*p4_parent);
   vertex(4,amp*norm*d->epsTensorParent(4).cont1(p4_parent)*p4_parent);
  
  }
 
 
  return ;
}

getName()

void EvtSSDCP::getName ( std::string & name )

virtual

Implements EvtDecayBase.

Definition at line 38 of file EvtSSDCP.cc.

                                           {
 
  model_name="SSD_CP";     
 
}

init()

void EvtSSDCP::init ( )

virtual

Reimplemented from EvtDecayBase.

Definition at line 51 of file EvtSSDCP.cc.

                   {
 
  // check that there are 8 or 12 or 14 arguments
 
  checkNArg(14,12,8);
  checkNDaug(2);
 
  EvtSpinType::spintype d1type=EvtPDL::getSpinType(getDaug(0));
  EvtSpinType::spintype d2type=EvtPDL::getSpinType(getDaug(1));
 
  // FS commented this check to include alias of B0
  //  if ( !((getParentId() == EvtPDL::getId("B0"))||(getParentId() == EvtPDL::getId("B0B"))) ) {
  //    report(ERROR, "EvtGen") << "EvtSSDCP cannot decay "
  //            << EvtPDL::name(getParentId()) 
  //            << ". Must be specified to decay"
  //            << " only B0 or a B0B ." << endl;
  //  report(ERROR,"EvtGen") << "Will terminate execution!"<<endl;
  //  ::abort();
  //}
 
  if ( (!(d1type == EvtSpinType::SCALAR || d2type == EvtSpinType::SCALAR))||
       (!((d2type==EvtSpinType::SCALAR)||(d2type==EvtSpinType::VECTOR)||(d2type==EvtSpinType::TENSOR)))||
       (!((d1type==EvtSpinType::SCALAR)||(d1type==EvtSpinType::VECTOR)||(d1type==EvtSpinType::TENSOR)))
       ) {
    report(ERROR,"EvtGen") << "EvtSSDCP generator expected "
                           << "one of the daugters to be a scalar, the other either scalar, vector, or tensor, found:"
               << EvtPDL::name(getDaug(0)).c_str()<<" and "<<EvtPDL::name(getDaug(1)).c_str()<<endl;
    report(ERROR,"EvtGen") << "Will terminate execution!"<<endl;
    ::abort();
  }
 
  _dm=getArg(0)/EvtConst::c; //units of 1/mm
 
  _dgog=getArg(1);
 
  
  _qoverp=getArg(2)*EvtComplex(cos(getArg(3)),sin(getArg(3)));
  _poverq=1.0/_qoverp;
 
  _A_f=getArg(4)*EvtComplex(cos(getArg(5)),sin(getArg(5)));
 
  _Abar_f=getArg(6)*EvtComplex(cos(getArg(7)),sin(getArg(7)));
  
  if (getNArg()>=12){
    _eigenstate=false;
    _A_fbar=getArg(8)*EvtComplex(cos(getArg(9)),sin(getArg(9)));
    _Abar_fbar=getArg(10)*EvtComplex(cos(getArg(11)),sin(getArg(11)));
  }
  else{
    //I'm somewhat confused about this. For a CP eigenstate set the
    //amplitudes to the same. For a non CP eigenstate CPT invariance
    //is enforced. (ryd)
    if (
    (getDaug(0)==EvtPDL::chargeConj(getDaug(0))&&
     getDaug(1)==EvtPDL::chargeConj(getDaug(1)))||
    (getDaug(0)==EvtPDL::chargeConj(getDaug(1))&&
     getDaug(1)==EvtPDL::chargeConj(getDaug(0)))){
      _eigenstate=true;
    }else{
      _eigenstate=false;
      _A_fbar=conj(_Abar_f);
      _Abar_fbar=conj(_A_f);
    }
  }
 
  //FS: new check for z 
  if (getNArg()==14){ //FS Set _z parameter if provided else set it 0
    _z=EvtComplex(getArg(12),getArg(13));
  }
  else{
    _z=EvtComplex(0.0,0.0);
  }
 
  // FS substituted next 2 lines...
 
 
  //
  //  _gamma=EvtPDL::getctau(EvtPDL::getId("B0"));  //units of 1/mm
  //_dgamma=_gamma*0.5*_dgog;
  //
  // ...with:
 
  _gamma=1/EvtPDL::getctau(EvtPDL::getId("B0")); //gamma/c (1/mm)
  _dgamma=_gamma*_dgog;  //dgamma/c (1/mm) 
 
  if (verbose()){
    report(INFO,"EvtGen") << "SSD_CP will generate CP/CPT violation:"
              << endl << endl
              << "    " << EvtPDL::name(getParentId()).c_str() << " --> "
              << EvtPDL::name(getDaug(0)).c_str() << " + "
              << EvtPDL::name(getDaug(1)).c_str() << endl << endl
              << "using parameters:" << endl << endl
              << "  delta(m)  = " << _dm << " hbar/ps" << endl
              << "dGamma      = "  << _dgamma <<" ps-1" <<endl
              << "       q/p  = " << _qoverp << endl  
              << "        z  = " << _z << endl  
              << "       tau  = " << 1./_gamma << " ps" << endl;
  }
 
}

initProbMax()

void EvtSSDCP::initProbMax ( )

virtual

Reimplemented from EvtDecayBase.

Definition at line 152 of file EvtSSDCP.cc.

                           {
  double theProbMax = 
    abs(_A_f) * abs(_A_f) +
    abs(_Abar_f) * abs(_Abar_f) +
    abs(_A_fbar) * abs(_A_fbar) +
    abs(_Abar_fbar) * abs(_Abar_fbar);
 
  if (_eigenstate) theProbMax*=2;
 
  EvtSpinType::spintype d2type=EvtPDL::getSpinType(getDaug(1));
  EvtSpinType::spintype d1type=EvtPDL::getSpinType(getDaug(0));
  if (d1type==EvtSpinType::TENSOR||d2type==EvtSpinType::TENSOR) theProbMax*=10;
 
  setProbMax(theProbMax);
}

---

The documentation for this class was generated from the following files:

• EvtSSDCP.hh
• EvtSSDCP.cc