EvtSVVNONCPEIGEN.cpp

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#include "EvtGenModels/EvtSVVNONCPEIGEN.hh"

#include "EvtGenBase/EvtCPUtil.hh"
#include "EvtGenBase/EvtConst.hh"
#include "EvtGenBase/EvtGenKine.hh"
#include "EvtGenBase/EvtPDL.hh"
#include "EvtGenBase/EvtParticle.hh"
#include "EvtGenBase/EvtPatches.hh"
#include "EvtGenBase/EvtRandom.hh"
#include "EvtGenBase/EvtReport.hh"
#include "EvtGenBase/EvtVector4C.hh"

#include "EvtGenModels/EvtSVVHelAmp.hh"

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

std::string EvtSVVNONCPEIGEN::getName()
{
    return "SVV_NONCPEIGEN";
}

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

void EvtSVVNONCPEIGEN::init()
{
    // check that there are 27 arguments
    checkNArg( 27, 15 );
    checkNDaug( 2 );

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

    //  The ordering of A_f is :
    //  A_f[0-2] = A_f
    //  A_f[3-5] = Abar_f
    //  A_f[6-8] = A_fbar
    //  A_f[9-11] = Abar_fbar
    //
    //  Each of the 4 amplitudes include the 3 different helicity states in
    //  the order +, 0, -. See more about helicity amplitude ordering in ::decay

    int i = 0;
    int j = ( getNArg() - 3 ) / 2;

    for ( i = 0; i < j; ++i ) {
        _A_f[i] = getArg( ( 2 * i ) + 3 ) *
                  EvtComplex( cos( getArg( ( 2 * i ) + 4 ) ),
                              sin( getArg( ( 2 * i ) + 4 ) ) );
    }

    //  If only 6 amplitudes are specified, calculate the last 6 from the first 6:
    if ( 6 == j ) {
        for ( i = 0; i < 3; ++i ) {
            _A_f[6 + i] = _A_f[3 + i];
            _A_f[9 + i] = _A_f[i];
        }
    }
}

void EvtSVVNONCPEIGEN::initProbMax()
{
    double probMax = 0;
    for ( int i = 0; i < 12; ++i ) {
        double amp = abs( _A_f[i] );
        probMax += amp * amp;
    }

    setProbMax( probMax );
}

void EvtSVVNONCPEIGEN::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;
    EvtId daugs[2];

    // MB: flip selects the final of the decay
    int flip = ( ( p->getId() == B0 ) ? 0 : 1 );
    daugs[0] = getDaug( 0 );
    daugs[1] = getDaug( 1 );
    p->initializePhaseSpace( 2, daugs );

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

    EvtComplex amp[3];

    double dmt2 = getArg( 0 ) * t / ( 2 * EvtConst::c );
    double phiCKM = ( 2.0 * getArg( 1 ) + getArg( 2 ) );    // 2b+g
    EvtComplex ePlusIPhi( cos( phiCKM ), sin( phiCKM ) );
    EvtComplex eMinusIPhi( cos( -phiCKM ), sin( -phiCKM ) );

    // flip == 0 : D*-rho+
    // flip == 1 : D*+rho-

    if ( !flip ) {
        if ( other_b == B0B ) {
            // At t=0 we have a B0
            for ( int i = 0; i < 3; ++i ) {
                amp[i] = _A_f[i] * cos( dmt2 ) +
                         eMinusIPhi * EvtComplex( 0.0, sin( dmt2 ) ) *
                             _A_f[i + 3];
            }
        }
        if ( other_b == B0 ) {
            // At t=0 we have a B0bar
            for ( int i = 0; i < 3; ++i ) {
                amp[i] = _A_f[i] * ePlusIPhi * EvtComplex( 0.0, sin( dmt2 ) ) +
                         _A_f[i + 3] * cos( dmt2 );
            }
        }
    } else {
        if ( other_b == B0B ) {
            // At t=0 we have a B0

            // M.Baak 01/16/2004
            // Note: \bar{H}+- = H-+
            // If one wants to use the correct helicities for B0 and B0bar decays but the same formula-notation (as done in EvtSVV_HelAmp),
            // count the B0bar helicities backwards. (Equivalently, one could flip the chi angle.)

            for ( int i = 0; i < 3; ++i ) {
                amp[i] = _A_f[8 - i] * cos( dmt2 ) +
                         eMinusIPhi * EvtComplex( 0.0, sin( dmt2 ) ) *
                             _A_f[11 - i];
            }
        }
        if ( other_b == B0 ) {
            // At t=0 we have a B0bar
            for ( int i = 0; i < 3; ++i ) {
                amp[i] = _A_f[8 - i] * ePlusIPhi * EvtComplex( 0.0, sin( dmt2 ) ) +
                         _A_f[11 - i] * cos( dmt2 );
            }
        }
    }

    EvtSVVHelAmp::SVVHel( p, _amp2, daugs[0], daugs[1], amp[0], amp[1], amp[2] );

    return;
}

std::string EvtSVVNONCPEIGEN::getParamName( int i )
{
    switch ( i ) {
        case 0:
            return "deltaM";
        case 1:
            return "weakPhase1";
        case 2:
            return "weakPhase2";
        case 3:
            return "AfPlusHelAmp";
        case 4:
            return "AfPlusHelAmpPhase";
        case 5:
            return "AfZeroHelAmp";
        case 6:
            return "AfZeroHelAmpPhase";
        case 7:
            return "AfMinusHelAmp";
        case 8:
            return "AfMinusHelAmpPhase";
        case 9:
            return "AbarfPlusHelAmp";
        case 10:
            return "AbarfPlusHelAmpPhase";
        case 11:
            return "AbarfZeroHelAmp";
        case 12:
            return "AbarfZeroHelAmpPhase";
        case 13:
            return "AbarfMinusHelAmp";
        case 14:
            return "AbarfMinusHelAmpPhase";
        case 15:
            return "AfbarPlusHelAmp";
        case 16:
            return "AfbarPlusHelAmpPhase";
        case 17:
            return "AfbarZeroHelAmp";
        case 18:
            return "AfbarZeroHelAmpPhase";
        case 19:
            return "AfbarMinusHelAmp";
        case 20:
            return "AfbarMinusHelAmpPhase";
        case 21:
            return "AbarfbarPlusHelAmp";
        case 22:
            return "AbarfbarPlusHelAmpPhase";
        case 23:
            return "AbarfbarZeroHelAmp";
        case 24:
            return "AbarfbarZeroHelAmpPhase";
        case 25:
            return "AbarfbarMinusHelAmp";
        case 26:
            return "AbarfbarMinusHelAmpPhase";
        default:
            return "";
    }
}

std::string EvtSVVNONCPEIGEN::getParamDefault( int i )
{
    switch ( i ) {
        case 3:
            return "1.0";
        case 4:
            return "0.0";
        case 5:
            return "1.0";
        case 6:
            return "0.0";
        case 7:
            return "1.0";
        case 8:
            return "0.0";
        case 9:
            return "1.0";
        case 10:
            return "0.0";
        case 11:
            return "1.0";
        case 12:
            return "0.0";
        case 13:
            return "1.0";
        case 14:
            return "0.0";
        default:
            return "";
    }
}