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727e9e2e | 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 | 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 | if(x[0]<3.5) y= par[3]*(TMath::Power(x[0],par[4]))*TMath::Exp(x[0]*par[5]); | |
45 | else y= x[0]/TMath::Power((1+TMath::Power(x[0]/par[0],par[1])),par[2]); | |
46 | 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 | 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 | AliDebug(1,Form("PID: %i, form: %s \n",iPID,sForm)); | |
61 | TString type(sForm); | |
62 | GenFunc func; | |
63 | ||
64 | if(type=="FLAT") { | |
65 | func=PtFlat; | |
66 | } else if(type=="DIST") { | |
67 | ||
68 | switch(TMath::Abs(iPID)) { | |
69 | ||
70 | case kLb : func=PtLbDist; break; | |
71 | case kLc : func=PtLcDist; break; | |
72 | case kXi_c : func=PtLcDist; break; | |
73 | case kB : func=PtLbDist; break; | |
74 | default : AliError(Form("Unknown particle type: %i, Pt dist is 0",iPID)); func=0; | |
75 | } | |
76 | }else { | |
77 | AliError(Form("Unknown Pt distribution %s. Pt distribution is set to 0 ",sForm)); | |
78 | func=0; | |
79 | } | |
80 | ||
81 | return func; | |
82 | } | |
83 | ||
84 | GenFunc AliGenITSULib::GetY(Int_t iPID, const char *sForm) const | |
85 | { | |
86 | GenFunc func; | |
87 | ||
88 | if(TMath::Abs(iPID) != kLc && TMath::Abs(iPID) != kLb && TMath::Abs(iPID) != kXi_c && TMath::Abs(iPID) != kB) { | |
89 | AliError(Form("Unknown PID: %i, form: %s, returning 0",iPID,sForm)); ////////// | |
90 | func=0; | |
91 | } else { | |
92 | func = YFlat; | |
93 | } | |
94 | return func; | |
95 | } | |
96 | ||
97 | GenFuncIp AliGenITSULib::GetIp(Int_t iPID, const char *sForm) const | |
98 | { | |
99 | AliDebug(1,Form(" %i - %s",iPID,sForm)); | |
100 | // Return pointer to particle type parameterisation | |
101 | GenFuncIp id; | |
102 | ||
103 | if(TMath::Abs(iPID) != kLc && TMath::Abs(iPID) != kLb && TMath::Abs(iPID) != kXi_c && TMath::Abs(iPID) != kB) { | |
104 | AliError(Form("Unknown PID: %i, form: %s, return 0",iPID,sForm)); ////////// | |
105 | id = 0; | |
106 | } else { | |
107 | switch (iPID){ | |
108 | case kLc: return id=IpLcPlus; | |
109 | case -kLc: return id=IpLcMinus; | |
110 | case kLb: return id=IpLb; | |
111 | case -kLb: return id=IpLbBar; | |
112 | case kXi_c: return id=IpXic; | |
113 | default : AliFatal(Form("Unknown particle type: %i",iPID)); id=0; | |
114 | } | |
115 | ||
116 | } | |
117 | ||
118 | return id; | |
119 | } |