1 /**************************************************************************
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2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
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4 * Author: The ALICE Off-line Project. *
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5 * Contributors are mentioned in the code where appropriate. *
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7 * Permission to use, copy, modify and distribute this software and its *
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8 * documentation strictly for non-commercial purposes is hereby granted *
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9 * without fee, provided that the above copyright notice appears in all *
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10 * copies and that both the copyright notice and this permission notice *
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11 * appear in the supporting documentation. The authors make no claims *
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12 * about the suitability of this software for any purpose. It is *
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13 * provided "as is" without express or implied warranty. *
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14 **************************************************************************/
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17 // Library class for particle pt and y distributions used for
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18 // ITS Upgrade related signal simulations.
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20 // Author: Annalisa Mastroserio <Annalisa.Mastroserio@cern.ch>
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23 #include <TPDGCode.h>
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25 #include <TRandom.h>
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26 #include <TString.h>
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28 #include "AliGenITSULib.h"
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31 ClassImp(AliGenITSULib)
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33 typedef Double_t (*GenFunc) (const Double_t*, const Double_t*);
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34 typedef Int_t (*GenFuncIp) (TRandom *);
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37 Double_t AliGenITSULib::PtLcDist( const Double_t *x, const Double_t *)
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40 // same shape as the Lb pt distribution for high pt were overestimated. The Lb fitting funcion has been
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41 // used from 3.5 GeV/c on. At smaller Pt, the shape is likely as sqrt(x)*exp(-x)
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42 Double_t par[6]={2.781336,1.353902,4.634330,(145479448.743187/202262270.892062),1.789479,-1.329143};
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44 if(x[0]<3.5) y= par[3]*(TMath::Power(x[0],par[4]))*TMath::Exp(x[0]*par[5]);
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45 else y= x[0]/TMath::Power((1+TMath::Power(x[0]/par[0],par[1])),par[2]);
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50 Double_t AliGenITSULib::PtLbDist( const Double_t *x, const Double_t *)
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52 // pt-distribution (fitted in 0-30 GeV/c)
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53 Double_t par[4]={3.42500e-03,6.18902,1.76908,3.24823};
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54 return par[0]*x[0]/TMath::Power((1+TMath::Power(x[0]/par[1],par[2])),par[3]);
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57 GenFunc AliGenITSULib::GetPt(Int_t iPID, const char * sForm) const
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59 // Return pointer to Pt parameterisation
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60 AliDebug(1,Form("PID: %i, form: %s \n",iPID,sForm));
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61 TString type(sForm);
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66 } else if(type=="DIST") {
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68 switch(TMath::Abs(iPID)) {
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70 case kLb : func=PtLbDist; break;
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71 case kLc : func=PtLcDist; break;
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72 case kXi_c : func=PtLcDist; break;
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73 case kBplus : func=PtLbDist; break;
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74 case kBzero : func=PtLbDist; break;
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75 case kDs : func=PtLcDist; break;
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76 case kDplus : func=PtLcDist; break;
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77 default : AliError(Form("Unknown particle type: %i, Pt dist is 0",iPID)); func=0;
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80 AliError(Form("Unknown Pt distribution %s. Pt distribution is set to 0 ",sForm));
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87 GenFunc AliGenITSULib::GetY(Int_t iPID, const char *sForm) const
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91 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) {
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92 AliError(Form("Unknown PID: %i, form: %s, returning 0",iPID,sForm)); //////////
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100 GenFuncIp AliGenITSULib::GetIp(Int_t iPID, const char *sForm) const
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102 AliDebug(1,Form(" %i - %s",iPID,sForm));
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103 // Return pointer to particle type parameterisation
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106 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) {
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107 AliError(Form("Unknown PID: %i, form: %s, return 0",iPID,sForm)); //////////
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111 case kLc : return id=IpLcPlus;
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112 case -kLc : return id=IpLcMinus;
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113 case kLb : return id=IpLb;
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114 case -kLb : return id=IpLbBar;
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115 case kXi_c : return id=IpXic;
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116 case -kXi_c : return id=IpXicBar;
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117 case kBplus : return id=IpBPlus;
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118 case kBzero : return id=IpB0;
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119 case -kBzero: return id=IpB0Bar;
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120 case -kBplus: return id=IpBMinus;
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121 case kDs : return id=IpDsPlus;
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122 case -kDs : return id=IpDsMinus;
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123 case kDplus : return id=IpDPlus;
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124 case -kDplus: return id=IpDMinus;
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125 default : AliFatal(Form("Unknown particle type: %i",iPID)); id=0;
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