PndCorrDistGenerator Class Reference

#include <PndCorrDistGenerator.h>

Inheritance diagram for PndCorrDistGenerator:

Public Member Functions
	PndCorrDistGenerator ()
	PndCorrDistGenerator (const Char_t *fileName)
virtual	~PndCorrDistGenerator ()
virtual Bool_t	ReadEvent (FairPrimaryGenerator *primGen)
void	SetParam ()
void	SetThetaRange (Double_t thetLow=0., Double_t thetHigh=0.)

Private Member Functions
void	CloseInput ()
Double_t	MaxBoltDistP (Double_t MeanP)
Double_t	MeanMomentum (Double_t thet)
	ClassDef (PndCorrDistGenerator, 3)

Private Attributes
Int_t	iEvent
const Char_t *	fFileName
	Event number. More...
TFile *	fInputFile
	Input file name. More...
TH2F *	fInputHist
	Pointer to input file. More...
TClonesArray *	fParticles
	Pointer to input histogramm 2D. More...
Int_t	fPdgType
	Particle array from PLUTO. More...
Bool_t	fParam
Double_t	fTheLow
Double_t	fTheHigh

Detailed Description

Definition at line 31 of file PndCorrDistGenerator.h.

Constructor & Destructor Documentation

PndCorrDistGenerator::PndCorrDistGenerator

(

)

Default constructor (should not be used)

Definition at line 24 of file PndCorrDistGenerator.cxx.

                                           {
  iEvent     = 0;
  fInputFile = NULL;
  fInputHist = NULL;
  fPdgType   = 0;
  fParam     = kFALSE; 
  fTheLow =0.;
  fTheHigh =0.;
}

PndCorrDistGenerator::PndCorrDistGenerator

(

const Char_t *

fileName

)

Standard constructor

Parameters

fileName

The input (PLUTO) file name

Definition at line 38 of file PndCorrDistGenerator.cxx.

                                                                 {
  iEvent     = 0;
  fFileName  = fileName;
  fInputFile = new TFile(fFileName);
  if(fParam){cout<<"choosing parametrization modell"<<endl;}
  else{
    cout<<" Random events gerated from a TH2D P(th) dist-->GiBUU Modell"<<endl;
    fInputHist = (TH2F*) fInputFile->Get("source");
  }
  
}

PndCorrDistGenerator::~PndCorrDistGenerator ( )

virtual

Destructor

Definition at line 53 of file PndCorrDistGenerator.cxx.

                                            {
  CloseInput();
}

Member Function Documentation

PndCorrDistGenerator::ClassDef ( PndCorrDistGenerator  , 3    )

private

void PndCorrDistGenerator::CloseInput ( )

private

Private method CloseInput. Just for convenience. Closes the input file properly. Called from destructor and from ReadEvent.

Definition at line 146 of file PndCorrDistGenerator.cxx.

                                      {
  if ( fInputFile ) {
    cout << "-I PndCorrDistGenerator: Closing input file " << fFileName
         << endl;
    fInputFile->Close();
    delete fInputFile;
  }
  fInputFile = NULL;
}

Double_t PndCorrDistGenerator::MaxBoltDistP ( Double_t  MeanP )

private

Definition at line 166 of file PndCorrDistGenerator.cxx.

References Double_t, sigma, CAMath::Sqrt(), and v.

                                                          {

      Double_t Et=0.,EK=0.,v=0.,gamma=0.,zet=0.,sigma=0.;
      
      Et = TMath::Sqrt((MeanP*MeanP)+ (1.321*1.321)); // rel.  energy, speed of light c = 1.
      v = MeanP/Et; // v = beta*c/Etotal
      gamma = 1./TMath::Sqrt(1.-(v*v)); // gamma factor
      EK = gamma*1.321 - 1.321; //rel. kinetic energy, mass of Xi_minus = 1.321 GeV/c2
      zet = EK/1.321;
                   
      
      sigma = TMath::Sqrt(3*zet);
      Double_t limLow,limHigh;
      limLow = MeanP*0.882;
      limHigh = MeanP*1.085;
      //Double_t beta = 
      
      TF1* MBol = new TF1("mb","TMath::Gaus(x,[0],[1])",limLow,limHigh);
      // TF1* MBol = new TF1("mb","TMath::Exp(-TMath::Sqrt(1.+ (TMath::Power(x/[0],2))))/(4*TMath::Power([0],3)*TMath::Pi()*[1]*TMath::BesselK(2,1/[1]))",-2.,3); 
      //TF1* MBol = new TF1("mb","x*x*[1]*TMath::Exp(-x/[0])/([0]*TMath::BesselK(2,1/[0]))",0.,3); 
      //MBol->SetParameter(0,1.321);
      //MBol->SetParameter(1,zet);
      // MBol->SetParameter(0,zet);
      //MBol->SetParameter(1,v);
      MBol->SetParameter(0,MeanP);
      MBol->SetParameter(1,sigma);
      
    cout << "-I PndCorrDistGenerator: Calculating Momentum distribution via MB <v >" << endl;
      Double_t fitval = MBol->GetRandom();
                                 
    return fitval;
 
}

Double_t PndCorrDistGenerator::MeanMomentum ( Double_t  thet )

private

Definition at line 157 of file PndCorrDistGenerator.cxx.

References Double_t.

                                                         {
 
    cout << "-I PndCorrDistGenerator: Calculating Mean Momentum as function of theta" << endl;
    //f(x) = exp(p0+p1*x)
    Double_t fitval = TMath::Exp((4.93964e-01)-(thet*1.41427e-02));
    return fitval;
 
}

Bool_t PndCorrDistGenerator::ReadEvent ( FairPrimaryGenerator *  primGen )

virtual

Reads on event from the input file and pushes the tracks onto the stack. Abstract method in base class.

Parameters

primGen

pointer to the FairPrimaryGenerator

Definition at line 60 of file PndCorrDistGenerator.cxx.

References CAMath::Cos(), Double_t, exp(), p, phi, pz, CAMath::Sin(), and theta.

                                                                    {

  // Check for input file
  if ( ! fInputFile ) {
    cout << "-E PndCorrDistGenerator: Input file nor open!" << endl;
    return kFALSE;
  }
  
  //defining kinematics variables, angle is expressed in degrees.

  Double_t phi, p=0.0,theta=0.0;
  Double_t pz=0.,py=0.,px=0.;


  phi = gRandom->Uniform(0,360)* TMath::DegToRad();

  TF1 *lan;//Landau
  TF1 *exp; // exponential
  TF1 *MBol; 
  // relativistic Maxwell Boltzmann dist <v> (Maxwell-Juettner dist), mean velocity 
  // For more INFO see, http://en.wikipedia.org/wiki/Maxwell–Jüttner_distribution

  Double_t mean_p=0.;

  if(fParam){

    //--> Landau, dsigma/dtheta dist

    //Constant     1.03980e+03 //Peak height (kFALSE-->0), no integral, 
    //MPV          1.10093e+01
    //Sigma        4.65284e+00  

    lan = new TF1("lan","1.03980e+03*TMath::Landau(x,[0],[1],0)",fTheLow,fTheHigh); 
    lan->SetParameters(1.10093e+01,4.65284e+00);

    // getting theta
    theta = lan->GetRandom();

    // <p> --- > Max. Boltzmann dist --> p

    //more or less -->exponential <P>(theta)
    //Constant     4.93964e-01   
    //  Slope       -1.41427e-02 
    
    
    mean_p = MeanMomentum(theta);// getting <p>
    p = MaxBoltDistP(mean_p);

    pz = p*TMath::Cos(theta* TMath::DegToRad());
    py = p*TMath::Sin(theta* TMath::DegToRad())*TMath::Sin(phi);
    px = p*TMath::Sin(theta* TMath::DegToRad())*TMath::Cos(phi);

  }else{
  //getting p and theta randomly from a TH2F object
  //both variables are correlated to each other
  //phi is independtly generated over the full angular range.

  fInputHist->GetRandom2(theta,p);

  

    pz = p*TMath::Cos(theta* TMath::DegToRad());
    py = p*TMath::Sin(theta* TMath::DegToRad())*TMath::Sin(phi);
    px = p*TMath::Sin(theta* TMath::DegToRad())*TMath::Cos(phi);
  }
    // vertex coordinates given during generation via prim generator
  
    // Give track to PrimaryGenerator
    // multiplocity equal to 1
    // pdg is -3312, corresponding to a Xi minus
    
    fPdgType==3312;

    //cout<<" generating Xi minus "<<px<<" "<<py<<" "<<pz<<endl;
    
    primGen->AddTrack(3312, px, py, pz, 0., 0., 0.);



  return kTRUE;

}

void PndCorrDistGenerator::SetParam ( )

inline

Definition at line 55 of file PndCorrDistGenerator.h.

References fParam.

Referenced by run(), run_test(), runSimHF_GiB_DC(), and sim_pid_runSimHF_GiB_DC().

{fParam=kTRUE;};

void PndCorrDistGenerator::SetThetaRange ( Double_t  thetLow = 0., Double_t  thetHigh = 0.  )

inline

Definition at line 56 of file PndCorrDistGenerator.h.

Referenced by run(), run_test(), runSimHF_GiB_DC(), and sim_pid_runSimHF_GiB_DC().

  {fTheLow = thetLow; fTheHigh = thetHigh;};

Member Data Documentation

const Char_t* PndCorrDistGenerator::fFileName

private

Event number.

Definition at line 63 of file PndCorrDistGenerator.h.

TFile* PndCorrDistGenerator::fInputFile

private

Input file name.

Definition at line 64 of file PndCorrDistGenerator.h.

TH2F* PndCorrDistGenerator::fInputHist

private

Pointer to input file.

Definition at line 65 of file PndCorrDistGenerator.h.

Bool_t PndCorrDistGenerator::fParam

private

Definition at line 68 of file PndCorrDistGenerator.h.

Referenced by SetParam().

TClonesArray* PndCorrDistGenerator::fParticles

private

Pointer to input histogramm 2D.

Definition at line 66 of file PndCorrDistGenerator.h.

Int_t PndCorrDistGenerator::fPdgType

private

Particle array from PLUTO.

Definition at line 67 of file PndCorrDistGenerator.h.

Double_t PndCorrDistGenerator::fTheHigh

private

Definition at line 69 of file PndCorrDistGenerator.h.

Double_t PndCorrDistGenerator::fTheLow

private

Definition at line 69 of file PndCorrDistGenerator.h.

Int_t PndCorrDistGenerator::iEvent

private

Definition at line 57 of file PndCorrDistGenerator.h.

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The documentation for this class was generated from the following files:

• PndCorrDistGenerator.h
• PndCorrDistGenerator.cxx