EvtSVVHelAmp.cpp

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#include "EvtGenModels/EvtSVVHelAmp.hh"

#include "EvtGenBase/EvtGenKine.hh"
#include "EvtGenBase/EvtId.hh"
#include "EvtGenBase/EvtPDL.hh"
#include "EvtGenBase/EvtParticle.hh"
#include "EvtGenBase/EvtPatches.hh"
#include "EvtGenBase/EvtReport.hh"
#include "EvtGenBase/EvtTensor3C.hh"
#include "EvtGenBase/EvtTensor4C.hh"
#include "EvtGenBase/EvtVector3C.hh"
#include "EvtGenBase/EvtVector3R.hh"
#include "EvtGenBase/EvtVector4C.hh"

#include <stdlib.h>
#include <string>

std::string EvtSVVHelAmp::getName()
{
    return "SVV_HELAMP";
}

EvtDecayBase* EvtSVVHelAmp::clone()
{
    return new EvtSVVHelAmp;
}

void EvtSVVHelAmp::init()
{
    // check that there are 6 arguments
    checkNArg( 6 );
    checkNDaug( 2 );

    checkSpinParent( EvtSpinType::SCALAR );

    checkSpinDaughter( 0, EvtSpinType::VECTOR );
    checkSpinDaughter( 1, EvtSpinType::VECTOR );
}

void EvtSVVHelAmp::initProbMax()
{
    setProbMax( getArg( 0 ) * getArg( 0 ) + getArg( 2 ) * getArg( 2 ) +
                getArg( 4 ) * getArg( 4 ) );
}

void EvtSVVHelAmp::decay( EvtParticle* p )
{
    SVVHel( p, _amp2, getDaug( 0 ), getDaug( 1 ),
            EvtComplex( getArg( 0 ) * cos( getArg( 1 ) ),
                        getArg( 0 ) * sin( getArg( 1 ) ) ),
            EvtComplex( getArg( 2 ) * cos( getArg( 3 ) ),
                        getArg( 2 ) * sin( getArg( 3 ) ) ),
            EvtComplex( getArg( 4 ) * cos( getArg( 5 ) ),
                        getArg( 4 ) * sin( getArg( 5 ) ) ) );

    return;
}

void EvtSVVHelAmp::SVVHel( EvtParticle* parent, EvtAmp& amp, EvtId n_v1,
                           EvtId n_v2, const EvtComplex& hp,
                           const EvtComplex& h0, const EvtComplex& hm )
{
    //  Routine to decay a vector into a vector and scalar.  Started
    //  by ryd on Oct 17, 1996.

    int tndaug = 2;
    EvtId tdaug[2];
    tdaug[0] = n_v1;
    tdaug[1] = n_v2;

    parent->initializePhaseSpace( tndaug, tdaug );

    EvtParticle *v1, *v2;
    v1 = parent->getDaug( 0 );
    v2 = parent->getDaug( 1 );

    EvtVector4R momv1 = v1->getP4();
    //EvtVector4R momv2 = v2->getP4();

    EvtVector3R v1dir( momv1.get( 1 ), momv1.get( 2 ), momv1.get( 3 ) );
    v1dir = v1dir / v1dir.d3mag();

    EvtComplex a = -0.5 * ( hp + hm );
    EvtComplex b = EvtComplex( 0.0, 0.5 ) * ( hp - hm );
    EvtComplex c = h0 + 0.5 * ( hp + hm );

    EvtTensor3C M = a * EvtTensor3C::id() + b * EvtGenFunctions::eps( v1dir ) +
                    c * EvtGenFunctions::directProd( v1dir, v1dir );

    EvtVector3C t0 = M.cont1( v1->eps( 0 ).vec().conj() );
    EvtVector3C t1 = M.cont1( v1->eps( 1 ).vec().conj() );
    EvtVector3C t2 = M.cont1( v1->eps( 2 ).vec().conj() );

    EvtVector3C eps0 = v2->eps( 0 ).vec().conj();
    EvtVector3C eps1 = v2->eps( 1 ).vec().conj();
    EvtVector3C eps2 = v2->eps( 2 ).vec().conj();

    amp.vertex( 0, 0, t0 * eps0 );
    amp.vertex( 0, 1, t0 * eps1 );
    amp.vertex( 0, 2, t0 * eps2 );

    amp.vertex( 1, 0, t1 * eps0 );
    amp.vertex( 1, 1, t1 * eps1 );
    amp.vertex( 1, 2, t1 * eps2 );

    amp.vertex( 2, 0, t2 * eps0 );
    amp.vertex( 2, 1, t2 * eps1 );
    amp.vertex( 2, 2, t2 * eps2 );

    return;
}

std::string EvtSVVHelAmp::getParamName( int i )
{
    switch ( i ) {
        case 0:
            return "plusHelAmp";
        case 1:
            return "plusHelAmpPhase";
        case 2:
            return "zeroHelAmp";
        case 3:
            return "zeroHelAmpPhase";
        case 4:
            return "minusHelAmp";
        case 5:
            return "minusHelAmpPhase";
        default:
            return "";
    }
}

std::string EvtSVVHelAmp::getParamDefault( int i )
{
    switch ( i ) {
        case 0:
            return "1.0";
        case 1:
            return "0.0";
        case 2:
            return "1.0";
        case 3:
            return "0.0";
        case 4:
            return "1.0";
        case 5:
            return "0.0";
        default:
            return "";
    }
}