LauBlattWeisskopfFactor.cc

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// Copyright University of Warwick 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 "LauBlattWeisskopfFactor.hh"
#include "LauParameter.hh"
#include "LauResonanceInfo.hh"

ClassImp(LauBlattWeisskopfFactor)


// Constructor
LauBlattWeisskopfFactor::LauBlattWeisskopfFactor( const LauResonanceInfo& resInfo, const BarrierType barrierType, const BlattWeisskopfCategory category ) :
        spin_(resInfo.getSpin()),
        radius_(new LauParameter("NEED_A_GOOD_NAME",resInfo.getBWRadius(),0.0,10.0,kTRUE)),
        barrierType_(barrierType)
{
        TString categoryName = this->setRadiusName( resInfo, category );
        std::cout << "INFO in LauBlattWeisskopfFactor constructor : creating radius parameter for category \"" << categoryName << "\", with initial value " << resInfo.getBWRadius() << std::endl;
}

LauBlattWeisskopfFactor::LauBlattWeisskopfFactor( const LauResonanceInfo& resInfo, const Double_t resRadius, const BarrierType barrierType, const BlattWeisskopfCategory category ) :
        spin_(resInfo.getSpin()),
        radius_(new LauParameter("NEED_A_GOOD_NAME",resRadius,0.0,10.0,kTRUE)),
        barrierType_(barrierType)
{
        TString categoryName = this->setRadiusName( resInfo, category );
        std::cout << "INFO in LauBlattWeisskopfFactor constructor : creating radius parameter for category \"" << categoryName << "\", with initial value " << resRadius << std::endl;
}

LauBlattWeisskopfFactor::~LauBlattWeisskopfFactor()
{
}

LauBlattWeisskopfFactor::LauBlattWeisskopfFactor( const LauBlattWeisskopfFactor& other, const UInt_t newSpin ) :
        spin_(newSpin),
        radius_(other.radius_->createClone()),
        barrierType_(other.barrierType_)
{
}

TString LauBlattWeisskopfFactor::setRadiusName( const LauResonanceInfo& resInfo, const BlattWeisskopfCategory category )
{
        TString name = "BarrierRadius_";
        TString categoryName;

        switch (category) {
                case Parent :
                        categoryName = "Parent";
                        break;
                case Indep :
                        categoryName = resInfo.getSanitisedName();
                        break;
                case Light :
                        categoryName = "Light";
                        break;
                case Kstar :
                        categoryName = "Kstar";
                        break;
                case Charm :
                        categoryName = "Charm";
                        break;
                case StrangeCharm :
                        categoryName = "StrangeCharm";
                        break;
                case Charmonium :
                        categoryName = "Charmonium";
                        break;
                case Beauty :
                        categoryName = "Beauty";
                        break;
                case StrangeBeauty :
                        categoryName = "StrangeBeauty";
                        break;
                case CharmBeauty :
                        categoryName = "CharmBeauty";
                        break;
                case Custom1 :
                        categoryName = "Custom1";
                        break;
                case Custom2 :
                        categoryName = "Custom2";
                        break;
                case Custom3 :
                        categoryName = "Custom3";
                        break;
                case Custom4 :
                        categoryName = "Custom4";
                        break;
                default :
                        categoryName = "Unknown";
                        break;
        }

        name.Append(categoryName);
        radius_->name(name);

        return categoryName;
}

LauBlattWeisskopfFactor* LauBlattWeisskopfFactor::createClone( const UInt_t newSpin )
{
        LauBlattWeisskopfFactor* clone = new LauBlattWeisskopfFactor( *this, newSpin );
        return clone;
}

Double_t LauBlattWeisskopfFactor::calcFormFactor( const Double_t p ) const
{
        // Calculate the requested form factor for the resonance, given the momentum value
        Double_t fFactor(1.0);

        // For scalars the form factor is always unity
        // TODO: and we currently don't have formulae for spin > 5
        if ( (spin_ == 0) || (spin_ > 5) ) {
                return fFactor;
        }

        const Double_t radius = radius_->value();
        const Double_t z = radius*radius*p*p;

        if ( barrierType_ == BWBarrier ) {
                if (spin_ == 1) {
                        fFactor = TMath::Sqrt(2.0*z/(z + 1.0));
                } else if (spin_ == 2) {
                        fFactor = TMath::Sqrt(13.0*z*z/(z*z + 3.0*z + 9.0));
                } else if (spin_ == 3) {
                        fFactor = TMath::Sqrt(277.0*z*z*z/(z*z*z + 6.0*z*z + 45.0*z + 225.0));
                } else if (spin_ == 4) {
                        fFactor = TMath::Sqrt(12746.0*z*z*z*z/(z*z*z*z + 10.0*z*z*z + 135.0*z*z + 1575.0*z + 11025.0));
                } else if (spin_ == 5) {
                        fFactor = TMath::Sqrt(998881.0*z*z*z*z*z/(z*z*z*z*z + 15.0*z*z*z*z + 315.0*z*z*z + 6300.0*z*z + 99225.0*z + 893025.0));
                }
        } else if ( barrierType_ == BWPrimeBarrier ) {
                if (spin_ == 1) {
                        fFactor = TMath::Sqrt(1.0/(z + 1.0));
                } else if (spin_ == 2) {
                        fFactor = TMath::Sqrt(1.0/(z*z + 3.0*z + 9.0));
                } else if (spin_ == 3) {
                        fFactor = TMath::Sqrt(1.0/(z*z*z + 6.0*z*z + 45.0*z + 225.0));
                } else if (spin_ == 4) {
                        fFactor = TMath::Sqrt(1.0/(z*z*z*z + 10.0*z*z*z + 135.0*z*z + 1575.0*z + 11025.0));
                } else if (spin_ == 5) {
                        fFactor = TMath::Sqrt(1.0/(z*z*z*z*z + 15.0*z*z*z*z + 315.0*z*z*z + 6300.0*z*z + 99225.0*z + 893025.0));
                }
        } else if ( barrierType_ == ExpBarrier ) {
                if (spin_ == 1) {
                        fFactor = TMath::Exp( -TMath::Sqrt(z) );
                } else if (spin_ == 2) {
                        fFactor = TMath::Exp( -z );
                } else if (spin_ == 3) {
                        fFactor = TMath::Exp( -TMath::Sqrt(z*z*z) );
                } else if (spin_ == 4) {
                        fFactor = TMath::Exp( -z*z );
                } else if (spin_ == 5) {
                        fFactor = TMath::Exp( -TMath::Sqrt(z*z*z*z*z) );
                }
        }

        return fFactor;
}