EvtVPHOtoVISR Class Reference

#include <EvtVPHOtoVISR.hh>

Inheritance diagram for EvtVPHOtoVISR:

Public Member Functions
	EvtVPHOtoVISR ()
virtual	~EvtVPHOtoVISR ()
void	getName (std::string &name)
EvtDecayBase *	clone ()
void	decay (EvtParticle *p)
void	init ()
void	initProbMax ()
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 28 of file EvtVPHOtoVISR.hh.

Constructor & Destructor Documentation

EvtVPHOtoVISR()

EvtVPHOtoVISR::EvtVPHOtoVISR ( )

inline

Definition at line 32 of file EvtVPHOtoVISR.hh.

{}

Referenced by clone().

~EvtVPHOtoVISR()

EvtVPHOtoVISR::~EvtVPHOtoVISR ( )

virtual

Definition at line 32 of file EvtVPHOtoVISR.cc.

{}

Member Function Documentation

clone()

EvtDecayBase * EvtVPHOtoVISR::clone ( )

virtual

Implements EvtDecayBase.

Definition at line 41 of file EvtVPHOtoVISR.cc.

                                  {
 
  return new EvtVPHOtoVISR;
 
}

decay()

void EvtVPHOtoVISR::decay ( EvtParticle * p )

virtual

Implements EvtDecayBase.

Definition at line 67 of file EvtVPHOtoVISR.cc.

                                        {
 
  //take photon along z-axis, either forward or backward.
  //Implement this as generating the photon momentum along 
  //the z-axis uniformly 
 
  double w=p->mass();
  double s=w*w;
 
  double L=2.0*log(w/0.000511);
  double alpha=1/137.0;
  double beta=(L-1)*2.0*alpha/EvtConst::pi;
 
  //This uses the fact that there is a daughter of the 
  //psi(3770)
  assert(p->getDaug(0)->getDaug(0)!=0);
  double md=EvtPDL::getMeanMass(p->getDaug(0)->getDaug(0)->getId());
 
  static double mD0=EvtPDL::getMeanMass(EvtPDL::getId("D0"));
  static double mDp=EvtPDL::getMeanMass(EvtPDL::getId("D+"));
 
  double pgmax=(s-4.0*md*md)/(2.0*w);
 
  assert(pgmax>0.0);
 
  double pgz=0.99*pgmax*exp(log(EvtRandom::Flat(1.0))/beta);
 
  if (EvtRandom::Flat(1.0)<0.5) pgz=-pgz;
 
  double k=fabs(pgz);
 
  EvtVector4R p4g(k,0.0,0.0,pgz);
 
  EvtVector4R p4res=p->getP4Restframe()-p4g;
 
  double mres=p4res.mass();
 
  double ed=mres/2.0;
 
  assert(ed>md);
 
  double pd=sqrt(ed*ed-md*md);
 
 
  //std::cout << "k, mres, w, md, ed, pd:"<<k<<" "<<mres<<" "<<w<<" "<<md<<" "<<ed<<" "<<pd<<std::endl;
 
  p->getDaug(0)->init(getDaug(0),p4res);
  p->getDaug(1)->init(getDaug(1),p4g);
 
 
  double sigma=beta*pow(2/w,beta)*(1+alpha*(1.5*L-2.0+EvtConst::pi*EvtConst::pi/3.0)/EvtConst::pi);
 
  double m=EvtPDL::getMeanMass(p->getDaug(0)->getId());
  double Gamma=EvtPDL::getWidth(p->getDaug(0)->getId());
 
  //mres is the energy of the psi(3770)
 
  double p0=0.0;
  if (ed>mD0) p0=sqrt(ed*ed-mD0*mD0);
  double pp=0.0;
  if (ed>mDp) pp=sqrt(ed*ed-mDp*mDp);
 
  double p0norm=sqrt(0.25*m*m-mD0*mD0);
  double ppnorm=sqrt(0.25*m*m-mDp*mDp);
 
  double r0=12.7;
  double rp=12.7;
 
  if (getNArg()==2){
    r0=getArg(0);
    rp=getArg(1);
  }
 
  double GammaTot=Gamma*(pp*pp*pp/(1+pp*pp*rp*rp)+p0*p0*p0/(1+p0*p0*r0*r0))/
    (ppnorm*ppnorm*ppnorm/(1+ppnorm*ppnorm*rp*rp)+
     p0norm*p0norm*p0norm/(1+p0norm*p0norm*r0*r0));
  
 
  sigma*=pd*pd*pd/((mres-m)*(mres-m)+0.25*GammaTot*GammaTot);
 
  assert(sigma>0.0);
 
  static double sigmax=sigma;
 
  if (sigma>sigmax){
    sigmax=sigma;
  }
 
 
 
  static int count=0;
 
  count++;
 
  //if (count%10000==0){
  //  std::cout << "sigma :"<<sigma<<std::endl;
  //  std::cout << "sigmax:"<<sigmax<<std::endl;
  //}
 
  double norm=sqrt(sigma);
 
  vertex(0,0,0,norm*p->eps(0)*p->epsParent(0).conj());
  vertex(1,0,0,norm*p->eps(1)*p->epsParent(0).conj());
  vertex(2,0,0,norm*p->eps(2)*p->epsParent(0).conj());
 
  vertex(0,1,0,norm*p->eps(0)*p->epsParent(1).conj());
  vertex(1,1,0,norm*p->eps(1)*p->epsParent(1).conj());
  vertex(2,1,0,norm*p->eps(2)*p->epsParent(1).conj());
 
  vertex(0,2,0,norm*p->eps(0)*p->epsParent(2).conj());
  vertex(1,2,0,norm*p->eps(1)*p->epsParent(2).conj());
  vertex(2,2,0,norm*p->eps(2)*p->epsParent(2).conj());
 
  vertex(0,0,1,norm*p->eps(0)*p->epsParent(0).conj());
  vertex(1,0,1,norm*p->eps(1)*p->epsParent(0).conj());
  vertex(2,0,1,norm*p->eps(2)*p->epsParent(0).conj());
 
  vertex(0,1,1,norm*p->eps(0)*p->epsParent(1).conj());
  vertex(1,1,1,norm*p->eps(1)*p->epsParent(1).conj());
  vertex(2,1,1,norm*p->eps(2)*p->epsParent(1).conj());
 
  vertex(0,2,1,norm*p->eps(0)*p->epsParent(2).conj());
  vertex(1,2,1,norm*p->eps(1)*p->epsParent(2).conj());
  vertex(2,2,1,norm*p->eps(2)*p->epsParent(2).conj());
 
  return;
}

getName()

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

virtual

Implements EvtDecayBase.

Definition at line 34 of file EvtVPHOtoVISR.cc.

                                                {
 
  model_name="VPHOTOVISR"; 
    
}

init()

void EvtVPHOtoVISR::init ( )

virtual

Reimplemented from EvtDecayBase.

Definition at line 47 of file EvtVPHOtoVISR.cc.

                        {
 
  // check that there are 0 or 2 arguments
  checkNArg(0,2);
 
  // check that there are 2 daughters
  checkNDaug(2);
 
  // check the parent and daughter spins
  checkSpinParent(EvtSpinType::VECTOR);
  checkSpinDaughter(0,EvtSpinType::VECTOR);
  checkSpinDaughter(1,EvtSpinType::PHOTON);
}

initProbMax()

void EvtVPHOtoVISR::initProbMax ( )

virtual

Reimplemented from EvtDecayBase.

Definition at line 61 of file EvtVPHOtoVISR.cc.

                                {
 
  //setProbMax(100000.0);
 
}      

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

• EvtVPHOtoVISR.hh
• EvtVPHOtoVISR.cc