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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 | $Log$ | |
6b236b6f | 18 | Revision 1.10 2001/10/15 16:44:46 morsch |
19 | - Possibility for vertex distribution truncation. | |
20 | - Write mc header with vertex position. | |
21 | ||
971816d4 | 22 | Revision 1.9 2001/07/27 17:09:36 morsch |
23 | Use local SetTrack, KeepTrack and SetHighWaterMark methods | |
24 | to delegate either to local stack or to stack owned by AliRun. | |
25 | (Piotr Skowronski, A.M.) | |
26 | ||
a99cf51f | 27 | Revision 1.8 2001/07/20 11:03:58 morsch |
28 | Issue warning message if used outside allowed eta range (-8 to 8). | |
29 | ||
5b0e4c0f | 30 | Revision 1.7 2001/07/17 12:41:01 morsch |
31 | - Calculation of fraction of event corresponding to selected pt-range corrected | |
32 | (R. Turrisi) | |
33 | - Parent weight corrected. | |
34 | ||
f25521b2 | 35 | Revision 1.6 2001/05/16 14:57:10 alibrary |
36 | New files for folders and Stack | |
37 | ||
9e1a0ddb | 38 | Revision 1.5 2000/12/21 16:24:06 morsch |
39 | Coding convention clean-up | |
40 | ||
675e9664 | 41 | Revision 1.4 2000/11/30 07:12:50 alibrary |
42 | Introducing new Rndm and QA classes | |
43 | ||
65fb704d | 44 | Revision 1.3 2000/10/02 21:28:06 fca |
45 | Removal of useless dependecies via forward declarations | |
46 | ||
94de3818 | 47 | Revision 1.2 2000/07/11 18:24:55 fca |
48 | Coding convention corrections + few minor bug fixes | |
49 | ||
aee8290b | 50 | Revision 1.1 2000/06/09 20:20:30 morsch |
51 | Same class as previously in AliSimpleGen.cxx | |
52 | All coding rule violations except RS3 corrected (AM) | |
53 | ||
790bbabf | 54 | */ |
675e9664 | 55 | |
56 | // Parameterisation of pi and K, eta and pt distributions | |
57 | // used for the ALICE TDRs. | |
58 | // eta: according to HIJING (shadowing + quenching) | |
59 | // pT : according to CDF measurement at 1.8 TeV | |
60 | // Author: andreas.morsch@cern.ch | |
61 | ||
62 | ||
790bbabf | 63 | //Begin_Html |
64 | /* | |
65 | <img src="picts/AliGeneratorClass.gif"> | |
66 | </pre> | |
67 | <br clear=left> | |
68 | <font size=+2 color=red> | |
69 | <p>The responsible person for this module is | |
70 | <a href="mailto:andreas.morsch@cern.ch">Andreas Morsch</a>. | |
71 | </font> | |
72 | <pre> | |
73 | */ | |
74 | //End_Html | |
75 | // // | |
76 | /////////////////////////////////////////////////////////////////// | |
77 | ||
78 | #include "AliGenHIJINGpara.h" | |
971816d4 | 79 | #include "AliGenEventHeader.h" |
790bbabf | 80 | #include "AliRun.h" |
81 | #include "AliConst.h" | |
82 | #include "AliPDG.h" | |
83 | ||
971816d4 | 84 | #include <TF1.h> |
85 | #include <TArrayF.h> | |
86 | ||
790bbabf | 87 | ClassImp(AliGenHIJINGpara) |
88 | ||
89 | AliGenHIJINGpara::AliGenHIJINGpara(const AliGenHIJINGpara & para) | |
90 | { | |
91 | // copy constructor | |
92 | } | |
93 | ||
94 | //_____________________________________________________________________________ | |
95 | static Double_t ptpi(Double_t *px, Double_t *) | |
96 | { | |
97 | // | |
98 | // PT-PARAMETERIZATION CDF, PRL 61(88) 1819 | |
99 | // POWER LAW FOR PT > 500 MEV | |
100 | // MT SCALING BELOW (T=160 MEV) | |
101 | // | |
102 | const Double_t kp0 = 1.3; | |
103 | const Double_t kxn = 8.28; | |
104 | const Double_t kxlim=0.5; | |
105 | const Double_t kt=0.160; | |
106 | const Double_t kxmpi=0.139; | |
107 | const Double_t kb=1.; | |
108 | Double_t y, y1, xmpi2, ynorm, a; | |
109 | Double_t x=*px; | |
110 | // | |
111 | y1=TMath::Power(kp0/(kp0+kxlim),kxn); | |
112 | xmpi2=kxmpi*kxmpi; | |
113 | ynorm=kb*(TMath::Exp(-sqrt(kxlim*kxlim+xmpi2)/kt)); | |
114 | a=ynorm/y1; | |
115 | if (x > kxlim) | |
116 | y=a*TMath::Power(kp0/(kp0+x),kxn); | |
117 | else | |
118 | y=kb*TMath::Exp(-sqrt(x*x+xmpi2)/kt); | |
119 | return y*x; | |
120 | } | |
121 | ||
122 | //_____________________________________________________________________________ | |
123 | static Double_t ptscal(Double_t pt, Int_t np) | |
124 | { | |
125 | // SCALING EN MASSE PAR RAPPORT A PTPI | |
126 | // MASS PI,K,ETA,RHO,OMEGA,ETA',PHI | |
127 | const Double_t khm[10] = {.13957,.493,.5488,.769,.7826,.958,1.02,0,0,0}; | |
128 | // VALUE MESON/PI AT 5 GEV | |
129 | const Double_t kfmax[10]={1.,0.3,0.55,1.0,1.0,1.0,1.0,0,0,0}; | |
130 | np--; | |
131 | Double_t f5=TMath::Power((( | |
132 | sqrt(100.018215)+2.)/(sqrt(100.+khm[np]*khm[np])+2.0)),12.3); | |
133 | Double_t fmax2=f5/kfmax[np]; | |
134 | // PIONS | |
135 | Double_t ptpion=100.*ptpi(&pt, (Double_t*) 0); | |
136 | Double_t fmtscal=TMath::Power((( | |
137 | sqrt(pt*pt+0.018215)+2.)/ (sqrt(pt*pt+khm[np]*khm[np])+2.0)),12.3)/ | |
138 | fmax2; | |
139 | return fmtscal*ptpion; | |
140 | } | |
141 | ||
142 | //_____________________________________________________________________________ | |
143 | static Double_t ptka( Double_t *px, Double_t *) | |
144 | { | |
145 | // | |
146 | // pt parametrisation for k | |
147 | // | |
148 | return ptscal(*px,2); | |
149 | } | |
150 | ||
151 | ||
152 | //_____________________________________________________________________________ | |
153 | static Double_t etapic( Double_t *py, Double_t *) | |
154 | { | |
155 | // | |
156 | // eta parametrisation for pi | |
157 | // | |
158 | const Double_t ka1 = 4913.; | |
159 | const Double_t ka2 = 1819.; | |
160 | const Double_t keta1 = 0.22; | |
161 | const Double_t keta2 = 3.66; | |
162 | const Double_t kdeta1 = 1.47; | |
163 | const Double_t kdeta2 = 1.51; | |
164 | Double_t y=TMath::Abs(*py); | |
165 | // | |
166 | Double_t ex1 = (y-keta1)*(y-keta1)/(2*kdeta1*kdeta1); | |
167 | Double_t ex2 = (y-keta2)*(y-keta2)/(2*kdeta2*kdeta2); | |
168 | return ka1*TMath::Exp(-ex1)+ka2*TMath::Exp(-ex2); | |
169 | } | |
170 | ||
171 | //_____________________________________________________________________________ | |
172 | static Double_t etakac( Double_t *py, Double_t *) | |
173 | { | |
174 | // | |
175 | // eta parametrisation for ka | |
176 | // | |
177 | const Double_t ka1 = 497.6; | |
178 | const Double_t ka2 = 215.6; | |
179 | const Double_t keta1 = 0.79; | |
180 | const Double_t keta2 = 4.09; | |
181 | const Double_t kdeta1 = 1.54; | |
182 | const Double_t kdeta2 = 1.40; | |
183 | Double_t y=TMath::Abs(*py); | |
184 | // | |
185 | Double_t ex1 = (y-keta1)*(y-keta1)/(2*kdeta1*kdeta1); | |
186 | Double_t ex2 = (y-keta2)*(y-keta2)/(2*kdeta2*kdeta2); | |
187 | return ka1*TMath::Exp(-ex1)+ka2*TMath::Exp(-ex2); | |
188 | } | |
189 | ||
190 | //_____________________________________________________________________________ | |
191 | AliGenHIJINGpara::AliGenHIJINGpara() | |
192 | :AliGenerator() | |
193 | { | |
194 | // | |
195 | // Default constructor | |
196 | // | |
197 | fPtpi = 0; | |
198 | fPtka = 0; | |
199 | fETApic = 0; | |
200 | fETAkac = 0; | |
971816d4 | 201 | SetCutVertexZ(); |
6b236b6f | 202 | SetPtRange(); |
790bbabf | 203 | } |
204 | ||
205 | //_____________________________________________________________________________ | |
206 | AliGenHIJINGpara::AliGenHIJINGpara(Int_t npart) | |
207 | :AliGenerator(npart) | |
208 | { | |
209 | // | |
210 | // Standard constructor | |
211 | // | |
212 | fName="HIGINGpara"; | |
213 | fTitle="HIJING Parametrisation Particle Generator"; | |
214 | fPtpi = 0; | |
215 | fPtka = 0; | |
216 | fETApic = 0; | |
217 | fETAkac = 0; | |
971816d4 | 218 | SetCutVertexZ(); |
6b236b6f | 219 | SetPtRange(); |
790bbabf | 220 | } |
221 | ||
222 | //_____________________________________________________________________________ | |
223 | AliGenHIJINGpara::~AliGenHIJINGpara() | |
224 | { | |
225 | // | |
226 | // Standard destructor | |
227 | // | |
228 | delete fPtpi; | |
229 | delete fPtka; | |
230 | delete fETApic; | |
231 | delete fETAkac; | |
232 | } | |
233 | ||
234 | //_____________________________________________________________________________ | |
235 | void AliGenHIJINGpara::Init() | |
236 | { | |
237 | // | |
238 | // Initialise the HIJING parametrisation | |
239 | // | |
240 | Float_t etaMin =-TMath::Log(TMath::Tan( | |
241 | TMath::Min((Double_t)fThetaMax/2,TMath::Pi()/2-1.e-10))); | |
242 | Float_t etaMax = -TMath::Log(TMath::Tan( | |
243 | TMath::Max((Double_t)fThetaMin/2,1.e-10))); | |
f25521b2 | 244 | fPtpi = new TF1("ptpi",&ptpi,0,20,0); |
245 | fPtka = new TF1("ptka",&ptka,0,20,0); | |
790bbabf | 246 | fETApic = new TF1("etapic",&etapic,etaMin,etaMax,0); |
247 | fETAkac = new TF1("etakac",&etakac,etaMin,etaMax,0); | |
f25521b2 | 248 | |
790bbabf | 249 | TF1 *etaPic0 = new TF1("etapic",&etapic,-7,7,0); |
250 | TF1 *etaKac0 = new TF1("etakac",&etakac,-7,7,0); | |
f25521b2 | 251 | |
252 | TF1 *ptPic0 = new TF1("ptpi",&ptpi,0.,15.,0); | |
253 | TF1 *ptKac0 = new TF1("ptka",&ptka,0.,15.,0); | |
254 | ||
790bbabf | 255 | Float_t intETApi = etaPic0->Integral(-0.5, 0.5); |
256 | Float_t intETAka = etaKac0->Integral(-0.5, 0.5); | |
f25521b2 | 257 | Float_t scalePi = 7316/(intETApi/1.5); |
258 | Float_t scaleKa = 684/(intETAka/2.0); | |
259 | ||
260 | // Fraction of events corresponding to the selected pt-range | |
261 | Float_t intPt = (0.877*ptPic0->Integral(0, 15)+ | |
262 | 0.123*ptKac0->Integral(0, 15)); | |
263 | Float_t intPtSel = (0.877*ptPic0->Integral(fPtMin, fPtMax)+ | |
264 | 0.123*ptKac0->Integral(fPtMin, fPtMax)); | |
265 | Float_t ptFrac = intPtSel/intPt; | |
266 | ||
267 | // Fraction of events corresponding to the selected eta-range | |
790bbabf | 268 | Float_t intETASel = (scalePi*etaPic0->Integral(etaMin, etaMax)+ |
269 | scaleKa*etaKac0->Integral(etaMin, etaMax)); | |
f25521b2 | 270 | // Fraction of events corresponding to the selected phi-range |
271 | Float_t phiFrac = (fPhiMax-fPhiMin)/2/TMath::Pi(); | |
272 | ||
273 | fParentWeight = Float_t(fNpart)/(intETASel*ptFrac*phiFrac); | |
790bbabf | 274 | |
9e1a0ddb | 275 | printf("%s: The number of particles in the selected kinematic region corresponds to %f percent of a full event\n ", |
276 | ClassName(),100.*fParentWeight); | |
5b0e4c0f | 277 | |
278 | // Issue warning message if etaMin or etaMax are outside the alowed range | |
279 | // of the parametrization | |
280 | if (etaMin < -8.001 || etaMax > 8.001) { | |
281 | printf("\n \n WARNING FROM AliGenHIJINGPara !"); | |
282 | printf("\n YOU ARE USING THE PARAMETERISATION OUTSIDE "); | |
283 | printf("\n THE ALLOWED PSEUDORAPIDITY RANGE (-8. - 8.)"); | |
284 | printf("\n YOUR LIMITS: %f %f \n \n ", etaMin, etaMax); | |
285 | } | |
790bbabf | 286 | } |
287 | ||
288 | //_____________________________________________________________________________ | |
289 | void AliGenHIJINGpara::Generate() | |
290 | { | |
291 | // | |
292 | // Generate one trigger | |
293 | // | |
294 | ||
295 | ||
296 | const Float_t kRaKpic=0.14; | |
297 | const Float_t kBorne=1/(1+kRaKpic); | |
298 | Float_t polar[3]= {0,0,0}; | |
299 | // | |
300 | const Int_t kPions[3] = {kPi0, kPiPlus, kPiMinus}; | |
301 | const Int_t kKaons[4] = {kK0Long, kK0Short, kKPlus, kKMinus}; | |
302 | // | |
303 | Float_t origin[3]; | |
304 | Float_t pt, pl, ptot; | |
305 | Float_t phi, theta; | |
306 | Float_t p[3]; | |
307 | Int_t i, part, nt, j; | |
308 | // | |
309 | TF1 *ptf; | |
310 | TF1 *etaf; | |
311 | // | |
312 | Float_t random[6]; | |
313 | // | |
314 | for (j=0;j<3;j++) origin[j]=fOrigin[j]; | |
971816d4 | 315 | |
316 | if(fVertexSmear == kPerEvent) { | |
317 | Float_t dv[3]; | |
318 | dv[2] = 1.e10; | |
319 | while(TMath::Abs(dv[2]) > fCutVertexZ*fOsigma[2]) { | |
320 | Rndm(random,6); | |
321 | for (j=0; j < 3; j++) { | |
322 | dv[j] = fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())* | |
323 | TMath::Sqrt(-2*TMath::Log(random[2*j+1])); | |
324 | } | |
790bbabf | 325 | } |
971816d4 | 326 | for (j=0; j < 3; j++) origin[j] += dv[j]; |
327 | } // if kPerEvent | |
328 | TArrayF eventVertex; | |
329 | eventVertex.Set(3); | |
330 | eventVertex[0] = origin[0]; | |
331 | eventVertex[1] = origin[1]; | |
332 | eventVertex[2] = origin[2]; | |
333 | ||
790bbabf | 334 | for(i=0;i<fNpart;i++) { |
335 | while(1) { | |
65fb704d | 336 | Rndm(random,3); |
790bbabf | 337 | if(random[0]<kBorne) { |
338 | part=kPions[Int_t (random[1]*3)]; | |
339 | ptf=fPtpi; | |
340 | etaf=fETApic; | |
341 | } else { | |
342 | part=kKaons[Int_t (random[1]*4)]; | |
343 | ptf=fPtka; | |
344 | etaf=fETAkac; | |
345 | } | |
346 | phi=fPhiMin+random[2]*(fPhiMax-fPhiMin); | |
347 | theta=2*TMath::ATan(TMath::Exp(-etaf->GetRandom())); | |
348 | if(theta<fThetaMin || theta>fThetaMax) continue; | |
349 | pt=ptf->GetRandom(); | |
350 | pl=pt/TMath::Tan(theta); | |
351 | ptot=TMath::Sqrt(pt*pt+pl*pl); | |
352 | if(ptot<fPMin || ptot>fPMax) continue; | |
353 | p[0]=pt*TMath::Cos(phi); | |
354 | p[1]=pt*TMath::Sin(phi); | |
355 | p[2]=pl; | |
aee8290b | 356 | if(fVertexSmear==kPerTrack) { |
65fb704d | 357 | Rndm(random,6); |
790bbabf | 358 | for (j=0;j<3;j++) { |
359 | origin[j]=fOrigin[j]+fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())* | |
360 | TMath::Sqrt(-2*TMath::Log(random[2*j+1])); | |
361 | } | |
362 | } | |
a99cf51f | 363 | SetTrack(fTrackIt,-1,part,p,origin,polar,0,kPPrimary,nt,fParentWeight); |
790bbabf | 364 | break; |
365 | } | |
366 | } | |
971816d4 | 367 | // Header |
368 | AliGenEventHeader* header = new AliGenEventHeader("HIJINGparam"); | |
369 | // Event Vertex | |
370 | header->SetPrimaryVertex(eventVertex); | |
371 | gAlice->SetGenEventHeader(header); | |
790bbabf | 372 | } |
373 | ||
374 | AliGenHIJINGpara& AliGenHIJINGpara::operator=(const AliGenHIJINGpara& rhs) | |
375 | { | |
376 | // Assignment operator | |
377 | return *this; | |
378 | } | |
379 | ||
6b236b6f | 380 | void AliGenHIJINGpara::SetPtRange(Float_t ptmin, Float_t ptmax) { |
381 | AliGenerator::SetPtRange(ptmin, ptmax); | |
382 | } | |
790bbabf | 383 |