GeneratorInterface/ExhumeInterface/plugins/QQ.cpp - master - githubmirror/cmssw

GeneratorInterface/ExhumeInterface/plugins/QQ.cpp
142 строки4 KB
Matti Kortelainen
Move contents of ExhumeHadronizer.{h,cc} to ExhumeGeneratorFilter
16 мар 2026, 11:45
16 мар 2026, 11:45c901e15
//-*-c++-*-
//-*-QQ.cpp-*-
//   Written by James Monk and Andrew Pilkington
////////////////////////////////////////////////////////////////////////////////

#include "QQ.h"

////////////////////////////////////////////////////////////////////////////////
Exhume::QQ::QQ(const edm::ParameterSet& pset) : TwoSpace(pset) {
  std::cout << std::endl << "   =QQ production selected=" << std::endl << std::endl;
  SetThetaMin(acos(0.95));
  Partons[0].Colour = 101;
  Partons[0].AntiColour = 0;
  Partons[1].Colour = 0;
  Partons[1].AntiColour = 101;
  //set default to bb production
  SetQuarkType(5);

  Name = "di-quark";
}
////////////////////////////////////////////////////////////////////////////////
double Exhume::QQ::SubProcess() {
  double qMassSq = PartonMass * PartonMass;
  double sintheta = 1.0 / InvSinTheta;
  double etsq = qMassSq * CosTheta * CosTheta + sintheta * sintheta * sHat / 4.0;
  double _Sigma = AlphaS(0.5 * SqrtsHat) * AlphaS(0.5 * SqrtsHat) * qMassSq * pow((1 - 4 * qMassSq * InvsHat), 1.5) /
                  (24.0 * etsq * etsq);

  _Sigma = _Sigma * Gev2fb;
  //val / by 2Pi so that integrate over Phi later

  return (_Sigma);
}

void Exhume::QQ::LIPS2Amp() {
  double Theta = acos(CosTheta);
  InvSinTheta = 1.0 / sin(Theta);

  return;
}

void Exhume::QQ::Amp2LIPS() { return; }

/*
////////////////////////////////////////////////////////////////////////////////
void Exhume::QQ::SetSubParameters(){
  double ThetaRand = double(rand())/RAND_MAX;
  CosTheta = GetValue(ThetaRand);
  Theta = acos(CosTheta);
  SinTheta = sin(Theta);
  InvSinTheta = 1.0/sin(Theta);
}
////////////////////////////////////////////////////////////////////////////////
double Exhume::QQ::SubParameterRange(){
  return(TotalIntegral);
}
////////////////////////////////////////////////////////////////////////////////
void Exhume::QQ::MaximiseSubParameters(){
  WeightInit(CosThetaMin,CosThetaMax);
  Theta = ThetaMin;
  InvSinTheta = 1.0/SinThetaMin;
}
////////////////////////////////////////////////////////////////////////////////
double Exhume::QQ::SubParameterWeight(){
  SubWgt = GetFunc(CosTheta);
  return(SubWgt);
}
////////////////////////////////////////////////////////////////////////////////
void Exhume::QQ::SetPartons(){
  E = 0.5*SqrtsHat;
  Phi = 2*PI*double(rand())/RAND_MAX;
  P = sqrt(E*E-qMassSq);
	Px = P*SinTheta*cos(Phi);
  Py = P*SinTheta*sin(Phi);
  Pz = P*CosTheta;
  
	Partons[0].p.setPx(Px);
  Partons[0].p.setPy(Py);
  Partons[0].p.setPz(Pz);
  Partons[0].p.setE(E);

  Partons[1].p.setPx(-Px);
  Partons[1].p.setPy(-Py);
  Partons[1].p.setPz(-Pz);
  Partons[1].p.setE(E);

  Partons[0].p.boost(CentralVector.boostVector());
  Partons[1].p.boost(CentralVector.boostVector());
  
  return;

}
/////////////////////////////////////////////////////////////////////////////// 
void Exhume::QQ::SetThetaMin(const double& ThetaMin_){
  ThetaMin = ThetaMin_;
  ThetaMax = PI - ThetaMin_;
  SinThetaMin = sin(ThetaMin);
  CosThetaMin = cos(ThetaMax);
  CosThetaMax = cos(ThetaMin); 
  return;
}
////////////////////////////////////////////////////////////////////////////////
double Exhume::QQ::WeightFunc(const double& CosTheta_){
  InvSinTheta = 1.0/sin(acos(CosTheta_));
  return(SinThetaMin*SinThetaMin*SinThetaMin*SinThetaMin
	 *InvSinTheta*InvSinTheta*InvSinTheta*InvSinTheta);
}

*/
////////////////////////////////////////////////////////////////////////////////
void Exhume::QQ::SetQuarkType(const int& _id) {
  Partons[0].id = _id;
  Partons[1].id = -_id;
  switch (_id) {
    case 1:
      PartonMass = 0.0;
      break;
    case 2:
      PartonMass = 0.0;
      break;
    case 3:
      PartonMass = StrangeMass;
      break;
    case 4:
      PartonMass = CharmMass;
      break;
    case 5:
      PartonMass = BottomMass;
      break;
    case 6:
      PartonMass = TopMass;
      break;
    default:
      std::cout << "\tYou have not entered a quark KF code" << std::endl;
      std::cout << "\tBottom Production Chosen" << std::endl;
      PartonMass = BottomMass;
      Partons[0].id = 5;
      Partons[1].id = -5;
      break;
  }
  return;
}