ThreeBodyAllOn1IntegralCalculator.h

// -*- C++ -*-
//
// ThreeBodyAllOn1IntegralCalculator.h is a part of Herwig - A multi-purpose Monte Carlo event generator
// Copyright (C) 2002-2019 The Herwig Collaboration
//
// Herwig is licenced under version 3 of the GPL, see COPYING for details.
// Please respect the MCnet academic guidelines, see GUIDELINES for details.
//
#ifndef HERWIG_ThreeBodyAllOn1IntegralCalculator_H
#define HERWIG_ThreeBodyAllOn1IntegralCalculator_H
// This is the declaration of the ThreeBodyAllOn1IntegralCalculator class.
 
#include "WidthCalculatorBase.h"
#include "Herwig/Utilities/GSLIntegrator.h"
 
namespace Herwig {
using namespace ThePEG;
 
template<class T>
class ThreeBodyAllOn1IntegralCalculator: public WidthCalculatorBase {
 
public:
 
  ThreeBodyAllOn1IntegralCalculator(int intype, Energy inmass, Energy inwidth,
                                    double inpow, T indGamma,int mode,
                                    Energy m1,Energy m2,Energy m3)
    : _variabletype(intype),_intmass(inmass),_intwidth(inwidth),
      _intpower(inpow),_mode(mode), _theDgamma(indGamma) {
    _m .resize(4);
    _m2.resize(4);
    _m[1]=m1;_m[2]=m2;_m[3]=m3;
    for(int ix=1;ix<4;++ix)_m2[ix]=sqr(_m[ix]);
  }
  
  Energy partialWidth(Energy2 q2) const;
 
  void resetMass(int imass,Energy mass) {
    assert(imass<4);
    _m[imass]=mass;
    _m2[imass]=mass*mass;
  }
 
  Energy getMass(const int imass) const {
    assert(imass<4);
    return _m[imass]; 
  }
 
  Energy otherMass(const int imass) const {
    assert(imass>0&&imass<4);
    if(imass==1)      return _m[2]+_m[3];
    else if(imass==2) return _m[1]+_m[3];
    else              return _m[1]+_m[2];
  }
 
  Energy operator ()(double argument) const;
  typedef double ArgType;
  typedef Energy ValType;
 
private:
 
  ThreeBodyAllOn1IntegralCalculator & 
  operator=(const ThreeBodyAllOn1IntegralCalculator &) = delete;
 
private:
 
  int _variabletype;
 
  Energy _intmass;
 
  Energy _intwidth;
 
  double _intpower;
 
 
  int _mode;
 
  mutable vector<Energy>  _m;
 
  mutable vector<Energy2> _m2;
 
  T _theDgamma;
 
  GSLIntegrator _integrator;
 
};
}
 
#ifndef ThePEG_TEMPLATES_IN_CC_FILE
 #include "ThreeBodyAllOn1IntegralCalculator.tcc"
#endif
 
#endif /* HERWIG_ThreeBodyAllOn1IntegralCalculator_H */