PWGLF/SPECTRA/Nuclei/B2/AliLnM2.cxx

   1 /*****************************************************************************
   2  * Project: RooFit                                                           *
   3  *                                                                           *
   4  * This code was autogenerated by RooClassFactory                            *
   5  *****************************************************************************/
   6
   7 // Your description goes here...
   8
   9 #include "Riostream.h"
  10
  11 #include "AliLnM2.h"
  12 #include "RooAbsReal.h"
  13 #include "RooAbsCategory.h"
  14 #include <math.h>
  15 #include "TMath.h"
  16
  17 ClassImp(AliLnM2)
  18
  19  AliLnM2::AliLnM2(const char *name, const char *title,
  20                         RooAbsReal& _x,
  21                         RooAbsReal& _mu,
  22                         RooAbsReal& _sigma,
  23                         RooAbsReal& _tau,
  24                         RooAbsReal& _p) :
  25    RooAbsPdf(name,title),
  26    x("x","x",this,_x),
  27    mu("mu","mu",this,_mu),
  28    sigma("sigma","sigma",this,_sigma),
  29    tau("tau","tau",this,_tau),
  30    p("p","p",this,_p)
  31  {
  32  }
  33
  34
  35  AliLnM2::AliLnM2(const AliLnM2& other, const char* name) :
  36    RooAbsPdf(other,name),
  37    x("x",this,other.x),
  38    mu("mu",this,other.mu),
  39    sigma("sigma",this,other.sigma),
  40    tau("tau",this,other.tau),
  41    p("p",this,other.p)
  42  {
  43  }
  44
  45 Double_t AliLnM2::evaluate() const
  46 {
  47 //
  48 // m^2 shape
  49 //
  50         if( x <= mu + tau)
  51         {
  52                 return TMath::Exp(-(x-mu)*(x-mu)/(2.*sigma*sigma));
  53         }
  54
  55         Double_t lambda = 2.*tau*TMath::Sqrt(p*p+mu+tau)/(sigma*sigma);
  56         Double_t a = TMath::Exp(-tau*tau/(2.*sigma*sigma)+2.*tau*(p*p+mu+tau)/(sigma*sigma));
  57
  58         return a*TMath::Exp(-lambda*TMath::Sqrt(p*p + x));
  59 }