PndMvdIdealPidAlgo Class Reference

#include <PndMvdIdealPidAlgo.h>

Static Public Member Functions
static void	CalcLikelihood (PndMvdPidCand *cand)

Static Private Member Functions
static double	LowerBoundary (double p, double m)
static double	LowerProtonBoundary (double momentum)
static double	LowerKaonBoundary (double momentum)
static double	LowerPionBoundary (double momentum)
static double	LandauIntegral (double x)

Static Private Attributes
static float	fpiMass =0.1396
static float	fkMass =0.4937
static float	fpMass =0.9383
static float	feMass =0.511e-3
static float	fc =2.99792458e8
static float	feb =0.14e-6
static double	fkShift =3.38598e-4
static double	fkScale =1.36362e-4
static double	fpiShift =3.09159e-4
static double	fpiScale =1.58696e-4
static double	fPRemainder =0.015
static double	fKRemainder =0.01
static double	fPiRemainder =0.001

Detailed Description

Definition at line 10 of file PndMvdIdealPidAlgo.h.

Member Function Documentation

void PndMvdIdealPidAlgo::CalcLikelihood ( PndMvdPidCand *  cand )

static

Definition at line 5 of file PndMvdIdealPidAlgo.cxx.

References dE, dx, fkMass, fKRemainder, fkScale, fkShift, fpiMass, fPiRemainder, fpiScale, fpiShift, fPRemainder, PndMvdPidCand::GetMvdHitdE(), PndMvdPidCand::GetMvdHitdx(), PndMvdPidCand::GetMvdHitMomentum(), PndMvdPidCand::GetMvdHits(), LandauIntegral(), LowerBoundary(), LowerKaonBoundary(), LowerPionBoundary(), LowerProtonBoundary(), and PndMvdPidCand::SetLikelihood().

Referenced by PndMvdPidIdealTask::Exec().

                                                           {
  //computes pid likelihoods for pi, k, p, mu and stores them in the likelihood map
  //with the map key used as pdg id. This is basically done by integrating the
  //respective energy loss distribution within the chosen selector limits

  double weightP;
  double weightK;
  double weightPi;

  double dE=0;
  double dx=0;
  double momentum=0;

  for (Int_t k=0;k<cand->GetMvdHits(); k++) {
    dE+=cand->GetMvdHitdE(k);
    dx+=cand->GetMvdHitdx(k);
    momentum+=cand->GetMvdHitMomentum(k);
  }

  if (dx>0) {
    double energyloss=dE/dx;
    momentum=momentum/cand->GetMvdHits();

    //Proton selector
    if (energyloss>=LowerProtonBoundary(momentum)) {
      weightP=1-fPRemainder;
      weightK=1-LandauIntegral((LowerProtonBoundary(momentum)-LowerBoundary(momentum, fkMass)-fkShift)/fkScale);
      weightPi=1-LandauIntegral((LowerProtonBoundary(momentum)-LowerBoundary(momentum, fpiMass)-fpiShift)/fpiScale);

    //Kaon selector
    } else if (energyloss>=LowerKaonBoundary(momentum)) {
      weightP=fPRemainder;
      weightK=LandauIntegral((LowerProtonBoundary(momentum)-LowerBoundary(momentum, fkMass)-fkShift)/fkScale)
             -fKRemainder;
      weightPi=LandauIntegral((LowerProtonBoundary(momentum)-LowerBoundary(momentum, fpiMass)-fpiShift)/fpiScale)
              -LandauIntegral((LowerKaonBoundary(momentum)-LowerBoundary(momentum, fpiMass)-fpiShift)/fpiScale);

    //Pion selector
    } else if (energyloss>=LowerPionBoundary(momentum)) {
      weightP=0;
      weightK=fKRemainder;
      weightPi=LandauIntegral((LowerKaonBoundary(momentum)-LowerBoundary(momentum, fpiMass)-fpiShift)/fpiScale)
              -fPiRemainder;

    //Electron selector
    } else {
      weightP=0;
      weightK=0;
      weightPi=fPiRemainder;
    }
  } else {
    weightP=1;
    weightK=1;
    weightPi=1;
  }

  //Muons have approximately the same distribution as pions.
  double sum=weightP+weightK+2*weightPi;
  weightP/=sum;
  weightK/=sum;
  weightPi/=sum;

  cand->SetLikelihood(211, weightPi);
  cand->SetLikelihood(2212, weightP);
  cand->SetLikelihood(321, weightK);
  cand->SetLikelihood(13, weightPi);
}

double PndMvdIdealPidAlgo::LandauIntegral ( double  x )

staticprivate

Definition at line 95 of file PndMvdIdealPidAlgo.cxx.

References exp().

Referenced by CalcLikelihood().

                                                  {
//compute integral approximation of a Landau-p.d.f from -INF to x
//with expected value 0 and deviation 1. Hard coded numbers have
//been fitted within their respective intervals.

  if (x<-0.8)
  //gauss
    return 0.199785*exp(-pow(x+0.149198,2)*0.769779);
  else if (x<0.5)
    //linear
    return 0.177214*(x+1.61437);
  else
    //power function
    return 1-19.0054*pow(x+5.860003,-1.84611);
}

double PndMvdIdealPidAlgo::LowerBoundary ( double  p, double  m  )

staticprivate

Definition at line 88 of file PndMvdIdealPidAlgo.cxx.

References fc, feb, feMass, and log().

Referenced by CalcLikelihood(), LowerKaonBoundary(), LowerPionBoundary(), and LowerProtonBoundary().

                                                           {
//Calculate the lower boundary of the energy loss distribution.

  double sqrfBeta=1/(1+pow(m/p,2));
  return 4.9312e-05 * (log(2*feMass*fc*fc/feb*sqrfBeta/(1-sqrfBeta))-sqrfBeta)/sqrfBeta;
};

double PndMvdIdealPidAlgo::LowerKaonBoundary ( double  momentum )

staticprivate

Definition at line 79 of file PndMvdIdealPidAlgo.cxx.

References fkMass, and LowerBoundary().

Referenced by CalcLikelihood().

                                                     {
  return LowerBoundary(p+0.02, fkMass)-3e-4;
};

double PndMvdIdealPidAlgo::LowerPionBoundary ( double  momentum )

staticprivate

Definition at line 83 of file PndMvdIdealPidAlgo.cxx.

References fpiMass, and LowerBoundary().

Referenced by CalcLikelihood().

                                                     {
  return LowerBoundary(p+0.01, fpiMass)-3e-4;
};

double PndMvdIdealPidAlgo::LowerProtonBoundary ( double  momentum )

staticprivate

Definition at line 75 of file PndMvdIdealPidAlgo.cxx.

References fpMass, and LowerBoundary().

Referenced by CalcLikelihood().

                                                       {
  return LowerBoundary(p+0.02, fpMass)-5e-4;
};

Member Data Documentation

float PndMvdIdealPidAlgo::fc =2.99792458e8

staticprivate

Definition at line 38 of file PndMvdIdealPidAlgo.h.

Referenced by LowerBoundary().

float PndMvdIdealPidAlgo::feb =0.14e-6

staticprivate

Definition at line 39 of file PndMvdIdealPidAlgo.h.

Referenced by LowerBoundary().

float PndMvdIdealPidAlgo::feMass =0.511e-3

staticprivate

Definition at line 37 of file PndMvdIdealPidAlgo.h.

Referenced by LowerBoundary().

float PndMvdIdealPidAlgo::fkMass =0.4937

staticprivate

Definition at line 35 of file PndMvdIdealPidAlgo.h.

Referenced by CalcLikelihood(), and LowerKaonBoundary().

double PndMvdIdealPidAlgo::fKRemainder =0.01

staticprivate

Definition at line 50 of file PndMvdIdealPidAlgo.h.

Referenced by CalcLikelihood().

double PndMvdIdealPidAlgo::fkScale =1.36362e-4

staticprivate

Definition at line 43 of file PndMvdIdealPidAlgo.h.

Referenced by CalcLikelihood().

double PndMvdIdealPidAlgo::fkShift =3.38598e-4

staticprivate

Definition at line 42 of file PndMvdIdealPidAlgo.h.

Referenced by CalcLikelihood().

float PndMvdIdealPidAlgo::fpiMass =0.1396

staticprivate

Definition at line 34 of file PndMvdIdealPidAlgo.h.

Referenced by CalcLikelihood(), and LowerPionBoundary().

double PndMvdIdealPidAlgo::fPiRemainder =0.001

staticprivate

Definition at line 51 of file PndMvdIdealPidAlgo.h.

Referenced by CalcLikelihood().

double PndMvdIdealPidAlgo::fpiScale =1.58696e-4

staticprivate

Definition at line 46 of file PndMvdIdealPidAlgo.h.

Referenced by CalcLikelihood().

double PndMvdIdealPidAlgo::fpiShift =3.09159e-4

staticprivate

Definition at line 45 of file PndMvdIdealPidAlgo.h.

Referenced by CalcLikelihood().

float PndMvdIdealPidAlgo::fpMass =0.9383

staticprivate

Definition at line 36 of file PndMvdIdealPidAlgo.h.

Referenced by LowerProtonBoundary().

double PndMvdIdealPidAlgo::fPRemainder =0.015

staticprivate

Definition at line 49 of file PndMvdIdealPidAlgo.h.

Referenced by CalcLikelihood().

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

• PndMvdIdealPidAlgo.h
• PndMvdIdealPidAlgo.cxx