EvtSVS.cpp

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#include "EvtGenModels/EvtSVS.hh"
 
#include "EvtGenBase/EvtGenKine.hh"
#include "EvtGenBase/EvtPDL.hh"
#include "EvtGenBase/EvtParticle.hh"
#include "EvtGenBase/EvtReport.hh"
#include "EvtGenBase/EvtVector4C.hh"
 
#include <stdlib.h>
#include <string>
 
std::string EvtSVS::getName() const
{
    return "SVS";
}
 
EvtDecayBase* EvtSVS::clone() const
{
    return new EvtSVS;
}
 
void EvtSVS::init()
{
    // check that there are 0 arguments
    checkNArg( 0 );
    checkNDaug( 2 );
 
    checkSpinParent( EvtSpinType::SCALAR );
 
    checkSpinDaughter( 0, EvtSpinType::VECTOR );
    checkSpinDaughter( 1, EvtSpinType::SCALAR );
}
 
void EvtSVS::initProbMax()
{
    setProbMax( 1.0 );
}
 
void EvtSVS::decay( EvtParticle* p )
{
    p->initializePhaseSpace( getNDaug(), getDaugs() );
 
    EvtParticle* v;
    v = p->getDaug( 0 );
    double massv = v->mass();
    EvtVector4R momv = v->getP4();
    EvtVector4R moms = p->getDaug( 1 )->getP4();
    EvtVector4R p4_parent = momv + moms;
 
    double norm = massv / ( momv.d3mag() * p->mass() );
    p4_parent = norm * p4_parent;
    vertex( 0, p4_parent * ( v->epsParent( 0 ) ) );
    vertex( 1, p4_parent * ( v->epsParent( 1 ) ) );
    vertex( 2, p4_parent * ( v->epsParent( 2 ) ) );
 
    return;
}