Changes for

[u/mrichter/AliRoot.git] / EVGEN / AliGenITSULib.cxx

/**************************************************************************\r
 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *\r
 *                                                                        *\r
 * Author: The ALICE Off-line Project.                                    *\r
 * Contributors are mentioned in the code where appropriate.              *\r
 *                                                                        *\r
 * Permission to use, copy, modify and distribute this software and its   *\r
 * documentation strictly for non-commercial purposes is hereby granted   *\r
 * without fee, provided that the above copyright notice appears in all   *\r
 * copies and that both the copyright notice and this permission notice   *\r
 * appear in the supporting documentation. The authors make no claims     *\r
 * about the suitability of this software for any purpose. It is          *\r
 * provided "as is" without express or implied warranty.                  *\r
 **************************************************************************/\r
\r
\r
// Library class for particle pt and y distributions used for \r
// ITS Upgrade related signal simulations.\r
//\r
// Author: Annalisa Mastroserio <Annalisa.Mastroserio@cern.ch>\r
//\r
\r
#include <TPDGCode.h>\r
#include <TMath.h>\r
#include <TRandom.h>\r
#include <TString.h>\r
\r
#include "AliGenITSULib.h"\r
#include "AliLog.h"\r
\r
ClassImp(AliGenITSULib)\r
\r
 typedef Double_t (*GenFunc)   (const Double_t*,  const Double_t*);\r
 typedef Int_t    (*GenFuncIp) (TRandom *);\r
\r
\r
Double_t AliGenITSULib::PtLcDist( const Double_t *x, const Double_t *)\r
{\r
 //     pt-distribution\r
 // same shape as the Lb pt distribution for high pt were overestimated. The Lb fitting funcion has been\r
 // used from 3.5 GeV/c on. At smaller Pt, the shape is likely as  sqrt(x)*exp(-x) \r
 Double_t par[6]={2.781336,1.353902,4.634330,(145479448.743187/202262270.892062),1.789479,-1.329143}; \r
 Double_t y=0;\r
 if(x[0]<3.5) y= par[3]*(TMath::Power(x[0],par[4]))*TMath::Exp(x[0]*par[5]);\r
 else y= x[0]/TMath::Power((1+TMath::Power(x[0]/par[0],par[1])),par[2]);\r
 return y;\r
}\r
\r
\r
Double_t AliGenITSULib::PtLbDist( const Double_t *x, const Double_t *)\r
{\r
 //     pt-distribution (fitted in 0-30 GeV/c)\r
 Double_t par[4]={3.42500e-03,6.18902,1.76908,3.24823};\r
 return par[0]*x[0]/TMath::Power((1+TMath::Power(x[0]/par[1],par[2])),par[3]);\r
}\r
\r
GenFunc AliGenITSULib::GetPt(Int_t iPID, const char * sForm) const\r
{\r
 // Return pointer to Pt parameterisation\r
 AliDebug(1,Form("PID: %i, form: %s \n",iPID,sForm));	\r
 TString type(sForm);\r
 GenFunc func;\r
\r
 if(type=="FLAT") {\r
  func=PtFlat;\r
 } else if(type=="DIST") {\r
\r
  switch(TMath::Abs(iPID)) {\r
\r
   case kLb    :    func=PtLbDist; break;  \r
   case kLc    :    func=PtLcDist; break;  \r
   case kXi_c  :    func=PtLcDist; break;\r
   case kBplus :    func=PtLbDist; break;\r
   case kBzero :    func=PtLbDist; break;\r
   case kDs    :    func=PtLcDist; break;\r
   case kDplus :    func=PtLcDist; break;\r
   default : AliError(Form("Unknown particle type: %i, Pt dist is 0",iPID));      func=0;\r
  } \r
 }else {\r
  AliError(Form("Unknown Pt distribution %s. Pt distribution is set to 0 ",sForm));\r
  func=0;\r
 }\r
\r
 return func;\r
}\r
\r
GenFunc AliGenITSULib::GetY(Int_t iPID, const char *sForm) const\r
{\r
 GenFunc func;\r
\r
 if(TMath::Abs(iPID) != kLc && TMath::Abs(iPID) != kLb && TMath::Abs(iPID) != kXi_c && TMath::Abs(iPID) != kBplus && TMath::Abs(iPID) != kBzero && TMath::Abs(iPID)!=kDplus && TMath::Abs(iPID)!=kDs) {\r
  AliError(Form("Unknown PID: %i, form: %s, returning 0",iPID,sForm));   //////////	\r
  func=0;\r
 } else { \r
  func = YFlat;\r
 }\r
 return func;\r
}\r
\r
GenFuncIp AliGenITSULib::GetIp(Int_t iPID, const char *sForm) const\r
{\r
 AliDebug(1,Form(" %i - %s",iPID,sForm));\r
 // Return pointer to particle type parameterisation\r
 GenFuncIp id;\r
\r
 if(TMath::Abs(iPID) != kLc && TMath::Abs(iPID) != kLb && TMath::Abs(iPID) != kXi_c && TMath::Abs(iPID) != kBplus && TMath::Abs(iPID) != kBzero && TMath::Abs(iPID)!=kDplus && TMath::Abs(iPID)!=kDs) {\r
  AliError(Form("Unknown PID: %i, form: %s, return 0",iPID,sForm));   //////////	\r
  id = 0;\r
 } else {\r
  switch (iPID){\r
   case kLc    :                                  return id=IpLcPlus;\r
   case -kLc   :                                  return id=IpLcMinus;\r
   case kLb    :                                  return id=IpLb;\r
   case -kLb   :                                  return id=IpLbBar;\r
   case kXi_c  :                                  return id=IpXic;\r
   case -kXi_c :                                  return id=IpXicBar;\r
   case kBplus :                                  return id=IpBPlus;\r
   case kBzero :                                  return id=IpB0;\r
   case -kBzero:                                  return id=IpB0Bar;\r
   case -kBplus:                                  return id=IpBMinus;\r
   case kDs    :                                  return id=IpDsPlus;\r
   case -kDs   :                                  return id=IpDsMinus;\r
   case kDplus :                                  return id=IpDPlus;\r
   case -kDplus:                                  return id=IpDMinus;\r
   default  : AliFatal(Form("Unknown particle type: %i",iPID));  id=0;\r
  }\r
\r
 }\r
\r
 return id;\r
}\r