Line data Source code
1 : /**************************************************************************
2 : * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
3 : * *
4 : * Author: The ALICE Off-line Project. *
5 : * Contributors are mentioned in the code where appropriate. *
6 : * *
7 : * Permission to use, copy, modify and distribute this software and its *
8 : * documentation strictly for non-commercial purposes is hereby granted *
9 : * without fee, provided that the above copyright notice appears in all *
10 : * copies and that both the copyright notice and this permission notice *
11 : * appear in the supporting documentation. The authors make no claims *
12 : * about the suitability of this software for any purpose. It is *
13 : * provided "as is" without express or implied warranty. *
14 : **************************************************************************/
15 :
16 :
17 : // Library class for particle pt and y distributions used for
18 : // ITS Upgrade related signal simulations.
19 : //
20 : // Author: Annalisa Mastroserio <Annalisa.Mastroserio@cern.ch>
21 : //
22 :
23 : #include <TPDGCode.h>
24 : #include <TMath.h>
25 : #include <TRandom.h>
26 : #include <TString.h>
27 :
28 : #include "AliGenITSULib.h"
29 : #include "AliLog.h"
30 :
31 6 : ClassImp(AliGenITSULib)
32 :
33 : typedef Double_t (*GenFunc) (const Double_t*, const Double_t*);
34 : typedef Int_t (*GenFuncIp) (TRandom *);
35 :
36 :
37 : Double_t AliGenITSULib::PtLcDist( const Double_t *x, const Double_t *)
38 : {
39 : // pt-distribution
40 : // same shape as the Lb pt distribution for high pt were overestimated. The Lb fitting funcion has been
41 : // used from 3.5 GeV/c on. At smaller Pt, the shape is likely as sqrt(x)*exp(-x)
42 : Double_t par[6]={2.781336,1.353902,4.634330,(145479448.743187/202262270.892062),1.789479,-1.329143};
43 : Double_t y=0;
44 0 : if(x[0]<3.5) y= par[3]*(TMath::Power(x[0],par[4]))*TMath::Exp(x[0]*par[5]);
45 0 : else y= x[0]/TMath::Power((1+TMath::Power(x[0]/par[0],par[1])),par[2]);
46 0 : return y;
47 : }
48 :
49 :
50 : Double_t AliGenITSULib::PtLbDist( const Double_t *x, const Double_t *)
51 : {
52 : // pt-distribution (fitted in 0-30 GeV/c)
53 : Double_t par[4]={3.42500e-03,6.18902,1.76908,3.24823};
54 0 : return par[0]*x[0]/TMath::Power((1+TMath::Power(x[0]/par[1],par[2])),par[3]);
55 : }
56 :
57 : GenFunc AliGenITSULib::GetPt(Int_t iPID, const char * sForm) const
58 : {
59 : // Return pointer to Pt parameterisation
60 0 : AliDebug(1,Form("PID: %i, form: %s \n",iPID,sForm));
61 0 : TString type(sForm);
62 : GenFunc func;
63 :
64 0 : if(type=="FLAT") {
65 : func=PtFlat;
66 0 : } else if(type=="DIST") {
67 :
68 0 : switch(TMath::Abs(iPID)) {
69 :
70 0 : case kLb : func=PtLbDist; break;
71 0 : case kLc : func=PtLcDist; break;
72 0 : case kXi_c : func=PtLcDist; break;
73 0 : case kBplus : func=PtLbDist; break;
74 0 : case kBzero : func=PtLbDist; break;
75 0 : case kDs : func=PtLcDist; break;
76 0 : case kDplus : func=PtLcDist; break;
77 0 : default : AliError(Form("Unknown particle type: %i, Pt dist is 0",iPID)); func=0;
78 0 : }
79 : }else {
80 0 : AliError(Form("Unknown Pt distribution %s. Pt distribution is set to 0 ",sForm));
81 : func=0;
82 : }
83 :
84 : return func;
85 0 : }
86 :
87 : GenFunc AliGenITSULib::GetY(Int_t iPID, const char *sForm) const
88 : {
89 : GenFunc func;
90 :
91 0 : 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) {
92 0 : AliError(Form("Unknown PID: %i, form: %s, returning 0",iPID,sForm)); //////////
93 : func=0;
94 0 : } else {
95 : func = YFlat;
96 : }
97 0 : return func;
98 : }
99 :
100 : GenFuncIp AliGenITSULib::GetIp(Int_t iPID, const char *sForm) const
101 : {
102 0 : AliDebug(1,Form(" %i - %s",iPID,sForm));
103 : // Return pointer to particle type parameterisation
104 : GenFuncIp id;
105 :
106 0 : 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) {
107 0 : AliError(Form("Unknown PID: %i, form: %s, return 0",iPID,sForm)); //////////
108 : id = 0;
109 0 : } else {
110 0 : switch (iPID){
111 0 : case kLc : return id=IpLcPlus;
112 0 : case -kLc : return id=IpLcMinus;
113 0 : case kLb : return id=IpLb;
114 0 : case -kLb : return id=IpLbBar;
115 0 : case kXi_c : return id=IpXic;
116 0 : case -kXi_c : return id=IpXicBar;
117 0 : case kBplus : return id=IpBPlus;
118 0 : case kBzero : return id=IpB0;
119 0 : case -kBzero: return id=IpB0Bar;
120 0 : case -kBplus: return id=IpBMinus;
121 0 : case kDs : return id=IpDsPlus;
122 0 : case -kDs : return id=IpDsMinus;
123 0 : case kDplus : return id=IpDPlus;
124 0 : case -kDplus: return id=IpDMinus;
125 0 : default : AliFatal(Form("Unknown particle type: %i",iPID)); id=0;
126 : }
127 :
128 : }
129 :
130 0 : return id;
131 0 : }
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