//=============================================================================
// decay particle
//=============================================================================
void EvtBToDDalitzCPK::decay( EvtParticle * p )
{
if ( _flag == 1 ) {
// PHSP
p -> initializePhaseSpace( getNDaug() , getDaugs() ) ;
vertex ( 0. ) ;
}
else if ( _flag == 2 ) {
// SVS
p->initializePhaseSpace(getNDaug(),getDaugs());
EvtParticle *v;
v = p->getDaug(0);
double massv = v->mass();
EvtVector4R momv = v->getP4();
EvtVector4R moms = p->getDaug(1)->getP4();
double m_parent = p->mass();
EvtVector4R p4_parent = momv+moms;
double norm=massv/(momv.d3mag()*m_parent);
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)));
}
}
void EvtSSD_DirectCP::decay( EvtParticle *p) {
bool flip = false ;
EvtId daugs[2];
// decide it is B or Bbar:
if ( EvtRandom::Flat(0.,1.) < ( ( 1. - _acp ) / 2. ) ) {
// it is a B
if ( EvtPDL::getStdHep( getParentId() ) < 0 ) flip = true ;
} else {
// it is a Bbar
if ( EvtPDL::getStdHep( getParentId() ) > 0 ) flip = true ;
}
if ( flip ) {
if ( ( isB0Mixed( p ) ) || ( isBsMixed( p ) ) ) {
p->getParent()
->setId( EvtPDL::chargeConj( p->getParent()->getId() ) ) ;
p->setId( EvtPDL::chargeConj( p->getId() ) ) ;
}
else {
p->setId( EvtPDL::chargeConj( p->getId() ) ) ;
}
}
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);
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(1.);
}
if (d2type==EvtSpinType::VECTOR) {
double norm=momv.mass()/(momv.d3mag()*p->mass());
vertex(0,norm*p4_parent*(d->epsParent(0)));
vertex(1,norm*p4_parent*(d->epsParent(1)));
vertex(2,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,norm*d->epsTensorParent(0).cont1(p4_parent)*p4_parent);
vertex(1,norm*d->epsTensorParent(1).cont1(p4_parent)*p4_parent);
vertex(2,norm*d->epsTensorParent(2).cont1(p4_parent)*p4_parent);
vertex(3,norm*d->epsTensorParent(3).cont1(p4_parent)*p4_parent);
vertex(4,norm*d->epsTensorParent(4).cont1(p4_parent)*p4_parent);
}
}