EvtSSSCPT.cpp

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#include "EvtGenModels/EvtSSSCPT.hh"

#include "EvtGenBase/EvtCPUtil.hh"
#include "EvtGenBase/EvtConst.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 <stdlib.h>
#include <string>

std::string EvtSSSCPT::getName()
{
    return "SSS_CPT";
}

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

void EvtSSSCPT::init()
{
    // check that there are 8 arguments
    checkNArg( 8 );
    checkNDaug( 2 );
}

void EvtSSSCPT::decay( EvtParticle* p )
{
    //added by Lange Jan4,2000
    static EvtId B0 = EvtPDL::getId( "B0" );
    static EvtId B0B = EvtPDL::getId( "anti-B0" );

    double t;
    EvtId other_b;

    EvtCPUtil::getInstance()->OtherB( p, t, other_b, 0.5 );

    p->initializePhaseSpace( getNDaug(), getDaugs() );

    EvtComplex amp;

    EvtComplex A, Abar;
    EvtComplex P, Q, D, Im;

    P = EvtComplex( cos( -getArg( 0 ) ), sin( -getArg( 0 ) ) );
    Q = EvtComplex( cos( getArg( 0 ) ), sin( getArg( 0 ) ) );
    D = EvtComplex( getArg( 6 ) * cos( getArg( 7 ) ),
                    getArg( 6 ) * sin( getArg( 7 ) ) );
    Im = EvtComplex( 0.0, 1.0 );

    A = EvtComplex( getArg( 2 ) * cos( getArg( 3 ) ),
                    getArg( 2 ) * sin( getArg( 3 ) ) );
    Abar = EvtComplex( getArg( 4 ) * cos( getArg( 5 ) ),
                       getArg( 4 ) * sin( getArg( 5 ) ) );

    if ( other_b == B0B ) {
        amp = A * cos( getArg( 1 ) * t / ( 2 * EvtConst::c ) ) +
              Im * sin( getArg( 1 ) * t / ( 2 * EvtConst::c ) ) *
                  ( Q / P * A + 2.0 * D * Abar );
    }
    if ( other_b == B0 ) {
        amp = Abar * cos( getArg( 1 ) * t / ( 2 * EvtConst::c ) ) +
              Im * sin( getArg( 1 ) * t / ( 2 * EvtConst::c ) ) *
                  ( P / Q * A - 2.0 * D * Abar );
    }

    vertex( amp );

    return;
}