LauKMatrixProdSVP.cc

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// Copyright University of Warwick 2008 - 2014.
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)

// Authors:
// Thomas Latham
// John Back
// Paul Harrison

#include "LauKMatrixProdSVP.hh"
#include "LauKMatrixPropagator.hh"

#include <iostream>

ClassImp(LauKMatrixProdSVP)

LauKMatrixProdSVP::LauKMatrixProdSVP(const TString& SVPName, Int_t channelIndex, Int_t resPairAmpInt,
                                     LauKMatrixPropagator* propagator, const LauDaughters* daughters,
                                     Bool_t useProdAdler) : 
        LauAbsResonance(SVPName, resPairAmpInt, daughters),
        thePropagator_(propagator),
        channelIndex_(channelIndex - 1), // channelIndex goes from 1 to nChannels.
        useProdAdler_(useProdAdler)
{
        // Constructor
        if (useProdAdler_) {
            std::cout<<"Creating K matrix production SVP "<<SVPName<<" with channelIndex = "
                     <<channelIndex<<" with s-dependent production Adler zero term"<<std::endl;
        } else {
            std::cout<<"Creating K matrix production SVP "<<SVPName<<" with channelIndex = "
                     <<channelIndex<<" with production Adler zero factor = 1"<<std::endl;
        }


}

LauKMatrixProdSVP::~LauKMatrixProdSVP() 
{
        // Destructor
}

LauComplex LauKMatrixProdSVP::resAmp(Double_t mass, Double_t spinTerm)
{
        std::cerr << "ERROR in LauKMatrixProdSVP::resAmp : This method shouldn't get called." << std::endl;
        std::cerr << "                                     Returning zero amplitude for mass = " << mass << " and spinTerm = " << spinTerm << "." << std::endl;
        return LauComplex(0.0, 0.0);
}

LauComplex LauKMatrixProdSVP::amplitude(const LauKinematics* kinematics)
{

        // Calculate the amplitude for the K-matrix production pole.
        // First, make sure the K-matrix propagator is up-to-date for 
        // the given centre-of-mass squared value ("s") from the kinematics.
        LauComplex amp(0.0, 0.0);

        if (thePropagator_ == 0) {
                std::cerr << "ERROR in LauKMatrixProdSVP::amplitude : The propagator is null" << std::endl;
                return amp;
        }

        thePropagator_->updatePropagator(kinematics);

        Double_t SVPTerm = thePropagator_->getProdSVPTerm();

        amp = thePropagator_->getPropTerm(channelIndex_);

        // Include Adler zero factor if requested
        Double_t adlerZero(1.0);
        if (useProdAdler_) {adlerZero = thePropagator_->getAdlerZero();}

        amp.rescale(SVPTerm*adlerZero);

        return amp;

}