LauKMatrixProdSVP.cc

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// Copyright University of Warwick 2008 - 2013.
// 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& poleName, Int_t channelIndex, Int_t resPairAmpInt,
                                     LauKMatrixPropagator* propagator, const LauDaughters* daughters) : 
        LauAbsResonance(poleName, 0.0, 0.0, 0, 0, resPairAmpInt, daughters),
        thePropagator_(propagator),
        channelIndex_(channelIndex - 1) // channelIndex goes from 1 to nChannels.
{
        // Constructor
}

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_);
        amp.rescale(SVPTerm);

        return amp;

}