StrangePotential.cc

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/*                                                                            
                                                                            
Nikolai Amelin, Ludmila Malinina, Timur Pocheptsov (C) JINR/Dubna
amelin@sunhe.jinr.ru, malinina@sunhe.jinr.ru, pocheptsov@sunhe.jinr.ru 
November. 2, 2006                                

*/

#include "GeneratorInterface/Hydjet2Interface/interface/StrangePotential.h"

double NAStrangePotential::CalculateStrangePotential() {
  double minFunction = this->operator()(fMinStrangePotential);
  double maxFunction = this->operator()(fMaxStrangePotential);

  int iter = 0;
  while (minFunction < 0.0 && iter++ < fNIteration) {
    fMinStrangePotential -= 0.5 * fMinStrangePotential;
    minFunction = this->operator()(fMinStrangePotential);
  }

  iter = 0;
  while (minFunction * maxFunction > 0.0 && iter++ < fNIteration) {
    fMaxStrangePotential += 1.5 * Abs(fMaxStrangePotential - fMinStrangePotential);
    maxFunction = this->operator()(fMaxStrangePotential);
  }

  if (minFunction * maxFunction > 0.0) {
    edm::LogError("StrangePotential") << "CalculateStrangePotential: minFunction*maxFunction is positive!";
    return 0.;
  }

  NAEquationSolver<NAStrangePotential>* theSolver =
      new NAEquationSolver<NAStrangePotential>(fNSolverIteration, fTolerance);

  theSolver->SetIntervalLimits(fMinStrangePotential, fMaxStrangePotential);

  if (!theSolver->Brent(*this))
    edm::LogError("StrangePotential") << "CalculateStrangePotential: the root is not found!";

  double strangePotential = theSolver->GetRoot();
  delete theSolver;
  return strangePotential;
}

//calculate hadron system strange density
double NAStrangePotential::CalculateStrangeDensity(const double strangePotential) {
  fGc.SetStrangePotential(strangePotential);
  fGc.SetTemperature(fTemperature);
  fGc.SetBaryonPotential(fBaryonPotential);
  return fGc.StrangenessDensity(fDatabase);
}