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790bbabf | 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 | $Log$ | |
675e9664 | 18 | Revision 1.4 2000/11/30 07:12:50 alibrary |
19 | Introducing new Rndm and QA classes | |
20 | ||
65fb704d | 21 | Revision 1.3 2000/10/02 21:28:06 fca |
22 | Removal of useless dependecies via forward declarations | |
23 | ||
94de3818 | 24 | Revision 1.2 2000/07/11 18:24:55 fca |
25 | Coding convention corrections + few minor bug fixes | |
26 | ||
aee8290b | 27 | Revision 1.1 2000/06/09 20:20:30 morsch |
28 | Same class as previously in AliSimpleGen.cxx | |
29 | All coding rule violations except RS3 corrected (AM) | |
30 | ||
790bbabf | 31 | */ |
675e9664 | 32 | |
33 | // Parameterisation of pi and K, eta and pt distributions | |
34 | // used for the ALICE TDRs. | |
35 | // eta: according to HIJING (shadowing + quenching) | |
36 | // pT : according to CDF measurement at 1.8 TeV | |
37 | // Author: andreas.morsch@cern.ch | |
38 | ||
39 | ||
790bbabf | 40 | //Begin_Html |
41 | /* | |
42 | <img src="picts/AliGeneratorClass.gif"> | |
43 | </pre> | |
44 | <br clear=left> | |
45 | <font size=+2 color=red> | |
46 | <p>The responsible person for this module is | |
47 | <a href="mailto:andreas.morsch@cern.ch">Andreas Morsch</a>. | |
48 | </font> | |
49 | <pre> | |
50 | */ | |
51 | //End_Html | |
52 | // // | |
53 | /////////////////////////////////////////////////////////////////// | |
54 | ||
55 | #include "AliGenHIJINGpara.h" | |
65fb704d | 56 | #include "TF1.h" |
790bbabf | 57 | #include "AliRun.h" |
58 | #include "AliConst.h" | |
59 | #include "AliPDG.h" | |
60 | ||
61 | ClassImp(AliGenHIJINGpara) | |
62 | ||
63 | AliGenHIJINGpara::AliGenHIJINGpara(const AliGenHIJINGpara & para) | |
64 | { | |
65 | // copy constructor | |
66 | } | |
67 | ||
68 | //_____________________________________________________________________________ | |
69 | static Double_t ptpi(Double_t *px, Double_t *) | |
70 | { | |
71 | // | |
72 | // PT-PARAMETERIZATION CDF, PRL 61(88) 1819 | |
73 | // POWER LAW FOR PT > 500 MEV | |
74 | // MT SCALING BELOW (T=160 MEV) | |
75 | // | |
76 | const Double_t kp0 = 1.3; | |
77 | const Double_t kxn = 8.28; | |
78 | const Double_t kxlim=0.5; | |
79 | const Double_t kt=0.160; | |
80 | const Double_t kxmpi=0.139; | |
81 | const Double_t kb=1.; | |
82 | Double_t y, y1, xmpi2, ynorm, a; | |
83 | Double_t x=*px; | |
84 | // | |
85 | y1=TMath::Power(kp0/(kp0+kxlim),kxn); | |
86 | xmpi2=kxmpi*kxmpi; | |
87 | ynorm=kb*(TMath::Exp(-sqrt(kxlim*kxlim+xmpi2)/kt)); | |
88 | a=ynorm/y1; | |
89 | if (x > kxlim) | |
90 | y=a*TMath::Power(kp0/(kp0+x),kxn); | |
91 | else | |
92 | y=kb*TMath::Exp(-sqrt(x*x+xmpi2)/kt); | |
93 | return y*x; | |
94 | } | |
95 | ||
96 | //_____________________________________________________________________________ | |
97 | static Double_t ptscal(Double_t pt, Int_t np) | |
98 | { | |
99 | // SCALING EN MASSE PAR RAPPORT A PTPI | |
100 | // MASS PI,K,ETA,RHO,OMEGA,ETA',PHI | |
101 | const Double_t khm[10] = {.13957,.493,.5488,.769,.7826,.958,1.02,0,0,0}; | |
102 | // VALUE MESON/PI AT 5 GEV | |
103 | const Double_t kfmax[10]={1.,0.3,0.55,1.0,1.0,1.0,1.0,0,0,0}; | |
104 | np--; | |
105 | Double_t f5=TMath::Power((( | |
106 | sqrt(100.018215)+2.)/(sqrt(100.+khm[np]*khm[np])+2.0)),12.3); | |
107 | Double_t fmax2=f5/kfmax[np]; | |
108 | // PIONS | |
109 | Double_t ptpion=100.*ptpi(&pt, (Double_t*) 0); | |
110 | Double_t fmtscal=TMath::Power((( | |
111 | sqrt(pt*pt+0.018215)+2.)/ (sqrt(pt*pt+khm[np]*khm[np])+2.0)),12.3)/ | |
112 | fmax2; | |
113 | return fmtscal*ptpion; | |
114 | } | |
115 | ||
116 | //_____________________________________________________________________________ | |
117 | static Double_t ptka( Double_t *px, Double_t *) | |
118 | { | |
119 | // | |
120 | // pt parametrisation for k | |
121 | // | |
122 | return ptscal(*px,2); | |
123 | } | |
124 | ||
125 | ||
126 | //_____________________________________________________________________________ | |
127 | static Double_t etapic( Double_t *py, Double_t *) | |
128 | { | |
129 | // | |
130 | // eta parametrisation for pi | |
131 | // | |
132 | const Double_t ka1 = 4913.; | |
133 | const Double_t ka2 = 1819.; | |
134 | const Double_t keta1 = 0.22; | |
135 | const Double_t keta2 = 3.66; | |
136 | const Double_t kdeta1 = 1.47; | |
137 | const Double_t kdeta2 = 1.51; | |
138 | Double_t y=TMath::Abs(*py); | |
139 | // | |
140 | Double_t ex1 = (y-keta1)*(y-keta1)/(2*kdeta1*kdeta1); | |
141 | Double_t ex2 = (y-keta2)*(y-keta2)/(2*kdeta2*kdeta2); | |
142 | return ka1*TMath::Exp(-ex1)+ka2*TMath::Exp(-ex2); | |
143 | } | |
144 | ||
145 | //_____________________________________________________________________________ | |
146 | static Double_t etakac( Double_t *py, Double_t *) | |
147 | { | |
148 | // | |
149 | // eta parametrisation for ka | |
150 | // | |
151 | const Double_t ka1 = 497.6; | |
152 | const Double_t ka2 = 215.6; | |
153 | const Double_t keta1 = 0.79; | |
154 | const Double_t keta2 = 4.09; | |
155 | const Double_t kdeta1 = 1.54; | |
156 | const Double_t kdeta2 = 1.40; | |
157 | Double_t y=TMath::Abs(*py); | |
158 | // | |
159 | Double_t ex1 = (y-keta1)*(y-keta1)/(2*kdeta1*kdeta1); | |
160 | Double_t ex2 = (y-keta2)*(y-keta2)/(2*kdeta2*kdeta2); | |
161 | return ka1*TMath::Exp(-ex1)+ka2*TMath::Exp(-ex2); | |
162 | } | |
163 | ||
164 | //_____________________________________________________________________________ | |
165 | AliGenHIJINGpara::AliGenHIJINGpara() | |
166 | :AliGenerator() | |
167 | { | |
168 | // | |
169 | // Default constructor | |
170 | // | |
171 | fPtpi = 0; | |
172 | fPtka = 0; | |
173 | fETApic = 0; | |
174 | fETAkac = 0; | |
175 | } | |
176 | ||
177 | //_____________________________________________________________________________ | |
178 | AliGenHIJINGpara::AliGenHIJINGpara(Int_t npart) | |
179 | :AliGenerator(npart) | |
180 | { | |
181 | // | |
182 | // Standard constructor | |
183 | // | |
184 | fName="HIGINGpara"; | |
185 | fTitle="HIJING Parametrisation Particle Generator"; | |
186 | fPtpi = 0; | |
187 | fPtka = 0; | |
188 | fETApic = 0; | |
189 | fETAkac = 0; | |
190 | } | |
191 | ||
192 | //_____________________________________________________________________________ | |
193 | AliGenHIJINGpara::~AliGenHIJINGpara() | |
194 | { | |
195 | // | |
196 | // Standard destructor | |
197 | // | |
198 | delete fPtpi; | |
199 | delete fPtka; | |
200 | delete fETApic; | |
201 | delete fETAkac; | |
202 | } | |
203 | ||
204 | //_____________________________________________________________________________ | |
205 | void AliGenHIJINGpara::Init() | |
206 | { | |
207 | // | |
208 | // Initialise the HIJING parametrisation | |
209 | // | |
210 | Float_t etaMin =-TMath::Log(TMath::Tan( | |
211 | TMath::Min((Double_t)fThetaMax/2,TMath::Pi()/2-1.e-10))); | |
212 | Float_t etaMax = -TMath::Log(TMath::Tan( | |
213 | TMath::Max((Double_t)fThetaMin/2,1.e-10))); | |
214 | fPtpi = new TF1("ptpi",&ptpi,0,20,0); | |
215 | fPtka = new TF1("ptka",&ptka,0,20,0); | |
216 | fETApic = new TF1("etapic",&etapic,etaMin,etaMax,0); | |
217 | fETAkac = new TF1("etakac",&etakac,etaMin,etaMax,0); | |
218 | TF1 *etaPic0 = new TF1("etapic",&etapic,-7,7,0); | |
219 | TF1 *etaKac0 = new TF1("etakac",&etakac,-7,7,0); | |
220 | Float_t intETApi = etaPic0->Integral(-0.5, 0.5); | |
221 | Float_t intETAka = etaKac0->Integral(-0.5, 0.5); | |
222 | Float_t scalePi=7316/(intETApi/1.5); | |
223 | Float_t scaleKa= 684/(intETAka/2.0); | |
224 | ||
225 | Float_t intPt = (0.877*etaPic0->Integral(0, 15)+ | |
226 | 0.123*etaKac0->Integral(0, 15)); | |
227 | Float_t intPtSel = (0.877*etaPic0->Integral(fPtMin, fPtMax)+ | |
228 | 0.123*etaKac0->Integral(fPtMin, fPtMax)); | |
229 | Float_t ptFrac = intPtSel/intPt; | |
230 | ||
231 | ||
232 | Float_t intETASel = (scalePi*etaPic0->Integral(etaMin, etaMax)+ | |
233 | scaleKa*etaKac0->Integral(etaMin, etaMax)); | |
234 | Float_t phiFrac = (fPhiMax-fPhiMin)/2/TMath::Pi(); | |
235 | fParentWeight = Float_t(fNpart)/intETASel*ptFrac*phiFrac; | |
236 | ||
237 | printf("\n The number of particles in the selected kinematic region corresponds to %f percent of a full event\n ", 100.*fParentWeight); | |
238 | ||
239 | } | |
240 | ||
241 | //_____________________________________________________________________________ | |
242 | void AliGenHIJINGpara::Generate() | |
243 | { | |
244 | // | |
245 | // Generate one trigger | |
246 | // | |
247 | ||
248 | ||
249 | const Float_t kRaKpic=0.14; | |
250 | const Float_t kBorne=1/(1+kRaKpic); | |
251 | Float_t polar[3]= {0,0,0}; | |
252 | // | |
253 | const Int_t kPions[3] = {kPi0, kPiPlus, kPiMinus}; | |
254 | const Int_t kKaons[4] = {kK0Long, kK0Short, kKPlus, kKMinus}; | |
255 | // | |
256 | Float_t origin[3]; | |
257 | Float_t pt, pl, ptot; | |
258 | Float_t phi, theta; | |
259 | Float_t p[3]; | |
260 | Int_t i, part, nt, j; | |
261 | // | |
262 | TF1 *ptf; | |
263 | TF1 *etaf; | |
264 | // | |
265 | Float_t random[6]; | |
266 | // | |
267 | for (j=0;j<3;j++) origin[j]=fOrigin[j]; | |
aee8290b | 268 | if(fVertexSmear==kPerEvent) { |
65fb704d | 269 | Rndm(random,6); |
790bbabf | 270 | for (j=0;j<3;j++) { |
271 | origin[j]+=fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())* | |
272 | TMath::Sqrt(-2*TMath::Log(random[2*j+1])); | |
273 | } | |
274 | } | |
275 | for(i=0;i<fNpart;i++) { | |
276 | while(1) { | |
65fb704d | 277 | Rndm(random,3); |
790bbabf | 278 | if(random[0]<kBorne) { |
279 | part=kPions[Int_t (random[1]*3)]; | |
280 | ptf=fPtpi; | |
281 | etaf=fETApic; | |
282 | } else { | |
283 | part=kKaons[Int_t (random[1]*4)]; | |
284 | ptf=fPtka; | |
285 | etaf=fETAkac; | |
286 | } | |
287 | phi=fPhiMin+random[2]*(fPhiMax-fPhiMin); | |
288 | theta=2*TMath::ATan(TMath::Exp(-etaf->GetRandom())); | |
289 | if(theta<fThetaMin || theta>fThetaMax) continue; | |
290 | pt=ptf->GetRandom(); | |
291 | pl=pt/TMath::Tan(theta); | |
292 | ptot=TMath::Sqrt(pt*pt+pl*pl); | |
293 | if(ptot<fPMin || ptot>fPMax) continue; | |
294 | p[0]=pt*TMath::Cos(phi); | |
295 | p[1]=pt*TMath::Sin(phi); | |
296 | p[2]=pl; | |
aee8290b | 297 | if(fVertexSmear==kPerTrack) { |
65fb704d | 298 | Rndm(random,6); |
790bbabf | 299 | for (j=0;j<3;j++) { |
300 | origin[j]=fOrigin[j]+fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())* | |
301 | TMath::Sqrt(-2*TMath::Log(random[2*j+1])); | |
302 | } | |
303 | } | |
65fb704d | 304 | gAlice->SetTrack(fTrackIt,-1,part,p,origin,polar,0,kPPrimary,nt,fParentWeight); |
790bbabf | 305 | break; |
306 | } | |
307 | } | |
308 | } | |
309 | ||
310 | AliGenHIJINGpara& AliGenHIJINGpara::operator=(const AliGenHIJINGpara& rhs) | |
311 | { | |
312 | // Assignment operator | |
313 | return *this; | |
314 | } | |
315 | ||
316 |