LauBelleNR.cc

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// Copyright University of Warwick 2004 - 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 <iostream>

#include "TMath.h"

#include "LauBelleNR.hh"
#include "LauDaughters.hh"
#include "LauParameter.hh"
#include "LauResonanceInfo.hh"

ClassImp(LauBelleNR)


LauBelleNR::LauBelleNR(LauResonanceInfo* resInfo, const LauAbsResonance::LauResonanceModel resType,
                       const Int_t resPairAmpInt, const LauDaughters* daughters) :
        LauAbsResonance(resInfo, resPairAmpInt, daughters),
        alpha_(0),
        model_(resType),
        forceLegendre_(kTRUE)
{
        TString parName = this->getSanitisedName();
        parName += "_alpha";
        alpha_ = resInfo->getExtraParameter( parName );
        if ( alpha_ == 0 ) {
                alpha_ = new LauParameter( parName, 0.0, 0.0, 10.0, kTRUE );
                alpha_->secondStage(kTRUE);
                resInfo->addExtraParameter( alpha_ );
        }
}

LauBelleNR::~LauBelleNR()
{
}

void LauBelleNR::initialise()
{
        const LauDaughters* daughters = this->getDaughters();
        Int_t resPairAmpInt = this->getPairInt();
        if ( daughters->gotSymmetricalDP() && resPairAmpInt != 3 ) {
                std::cerr << "WARNING in LauBelleNR::initialise : Dalitz plot is symmetric - this lineshape is not appropriate." << std::endl;
        }

        if ( model_ != LauAbsResonance::BelleNR && model_ != LauAbsResonance::PowerLawNR ) {
                std::cerr << "WARNING in LauBelleNR::initialise : Unknown model requested, defaulting to exponential." << std::endl;
                model_ = LauAbsResonance::BelleNR;
        }

        // Make the spin term purely the Legendre polynomial of the cos(helicity angle)
        if ( forceLegendre_ ) {
                this->setSpinType( LauAbsResonance::Legendre );
        }
}

LauComplex LauBelleNR::resAmp(Double_t mass, Double_t spinTerm)
{
        Double_t magnitude(1.0);

        Double_t alpha = this->getAlpha();

        if ( model_ == LauAbsResonance::BelleNR ) {
                magnitude = spinTerm * TMath::Exp(-alpha*mass*mass);
        } else if ( model_ == LauAbsResonance::PowerLawNR ) {
                magnitude = spinTerm * TMath::Power(mass*mass, -alpha);
        }

        LauComplex resAmplitude(magnitude, 0.0);

        return resAmplitude;
}

const std::vector<LauParameter*>& LauBelleNR::getFloatingParameters()
{
        this->clearFloatingParameters();

        if ( ! this->fixAlpha() ) {
                this->addFloatingParameter( alpha_ );
        }

        return this->getParameters();
}

void LauBelleNR::setResonanceParameter(const TString& name, const Double_t value) 
{
        // Set various parameters for the lineshape
        if (name == "alpha") {
                this->setAlpha(value);
                std::cout << "INFO in LauBelleNR::setResonanceParameter : Setting parameter alpha = " << this->getAlpha() << std::endl;
        } else {
                std::cerr << "WARNING in LauBelleNR::setResonanceParameter: Parameter name not reconised.  No parameter changes made." << std::endl;
        }
}

void LauBelleNR::floatResonanceParameter(const TString& name)
{
        if (name == "alpha") {
                if ( alpha_->fixed() ) { 
                        alpha_->fixed( kFALSE );
                        this->addFloatingParameter( alpha_ );
                } else {
                        std::cerr << "WARNING in LauBelleNR::floatResonanceParameter: Parameter already floating.  No parameter changes made." << std::endl;
                }
        } else {
                std::cerr << "WARNING in LauBelleNR::fixResonanceParameter: Parameter name not reconised.  No parameter changes made." << std::endl;
        }
}

LauParameter* LauBelleNR::getResonanceParameter(const TString& name)
{
        if (name == "alpha") {
                return alpha_;
        } else {
                std::cerr << "WARNING in LauBelleNR::getResonanceParameter: Parameter name not reconised." << std::endl;
                return 0;
        }
}

void LauBelleNR::setAlpha(const Double_t alpha)
{
        alpha_->value( alpha );
        alpha_->genValue( alpha );
        alpha_->initValue( alpha );
}