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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 | $Log$ | |
56fcdfe6 | 18 | Revision 1.17 2002/12/10 17:44:57 morsch |
19 | Correct mother child relation for pi0. | |
20 | ||
1e66857c | 21 | Revision 1.16 2002/11/28 11:46:15 morsch |
22 | Don't track pi0 if already decayed. | |
23 | ||
1ef5f15d | 24 | Revision 1.15 2002/11/28 11:38:53 morsch |
25 | Typo corrected. | |
26 | ||
7b33c00a | 27 | Revision 1.14 2002/11/26 17:12:36 morsch |
28 | Decay pi0 if requested. | |
29 | ||
2067f62c | 30 | Revision 1.13 2002/10/14 14:55:35 hristov |
31 | Merging the VirtualMC branch to the main development branch (HEAD) | |
32 | ||
b9d0a01d | 33 | Revision 1.11.4.1 2002/07/24 08:56:28 alibrary |
34 | Updating EVGEN on TVirtulaMC | |
35 | ||
36 | Revision 1.12 2002/06/19 06:56:34 hristov | |
37 | Memory leak corrected | |
38 | ||
aecf26a3 | 39 | Revision 1.11 2002/03/20 10:21:13 hristov |
40 | Set fPtMax to 15 GeV in order to avoid some numerical problems | |
41 | ||
6b236b6f | 42 | Revision 1.10 2001/10/15 16:44:46 morsch |
43 | - Possibility for vertex distribution truncation. | |
44 | - Write mc header with vertex position. | |
45 | ||
971816d4 | 46 | Revision 1.9 2001/07/27 17:09:36 morsch |
47 | Use local SetTrack, KeepTrack and SetHighWaterMark methods | |
48 | to delegate either to local stack or to stack owned by AliRun. | |
49 | (Piotr Skowronski, A.M.) | |
50 | ||
a99cf51f | 51 | Revision 1.8 2001/07/20 11:03:58 morsch |
52 | Issue warning message if used outside allowed eta range (-8 to 8). | |
53 | ||
5b0e4c0f | 54 | Revision 1.7 2001/07/17 12:41:01 morsch |
55 | - Calculation of fraction of event corresponding to selected pt-range corrected | |
56 | (R. Turrisi) | |
57 | - Parent weight corrected. | |
58 | ||
f25521b2 | 59 | Revision 1.6 2001/05/16 14:57:10 alibrary |
60 | New files for folders and Stack | |
61 | ||
9e1a0ddb | 62 | Revision 1.5 2000/12/21 16:24:06 morsch |
63 | Coding convention clean-up | |
64 | ||
675e9664 | 65 | Revision 1.4 2000/11/30 07:12:50 alibrary |
66 | Introducing new Rndm and QA classes | |
67 | ||
65fb704d | 68 | Revision 1.3 2000/10/02 21:28:06 fca |
69 | Removal of useless dependecies via forward declarations | |
70 | ||
94de3818 | 71 | Revision 1.2 2000/07/11 18:24:55 fca |
72 | Coding convention corrections + few minor bug fixes | |
73 | ||
aee8290b | 74 | Revision 1.1 2000/06/09 20:20:30 morsch |
75 | Same class as previously in AliSimpleGen.cxx | |
76 | All coding rule violations except RS3 corrected (AM) | |
77 | ||
790bbabf | 78 | */ |
675e9664 | 79 | |
80 | // Parameterisation of pi and K, eta and pt distributions | |
81 | // used for the ALICE TDRs. | |
82 | // eta: according to HIJING (shadowing + quenching) | |
83 | // pT : according to CDF measurement at 1.8 TeV | |
84 | // Author: andreas.morsch@cern.ch | |
85 | ||
86 | ||
790bbabf | 87 | //Begin_Html |
88 | /* | |
89 | <img src="picts/AliGeneratorClass.gif"> | |
90 | </pre> | |
91 | <br clear=left> | |
92 | <font size=+2 color=red> | |
93 | <p>The responsible person for this module is | |
94 | <a href="mailto:andreas.morsch@cern.ch">Andreas Morsch</a>. | |
95 | </font> | |
96 | <pre> | |
97 | */ | |
98 | //End_Html | |
99 | // // | |
100 | /////////////////////////////////////////////////////////////////// | |
101 | ||
102 | #include "AliGenHIJINGpara.h" | |
971816d4 | 103 | #include "AliGenEventHeader.h" |
790bbabf | 104 | #include "AliRun.h" |
105 | #include "AliConst.h" | |
2067f62c | 106 | #include "AliDecayer.h" |
107 | #include "AliDecayerPythia.h" | |
790bbabf | 108 | #include "AliPDG.h" |
109 | ||
971816d4 | 110 | #include <TF1.h> |
111 | #include <TArrayF.h> | |
2067f62c | 112 | #include <TDatabasePDG.h> |
113 | #include <TClonesArray.h> | |
114 | #include <TParticle.h> | |
971816d4 | 115 | |
790bbabf | 116 | ClassImp(AliGenHIJINGpara) |
117 | ||
118 | AliGenHIJINGpara::AliGenHIJINGpara(const AliGenHIJINGpara & para) | |
119 | { | |
120 | // copy constructor | |
121 | } | |
122 | ||
123 | //_____________________________________________________________________________ | |
124 | static Double_t ptpi(Double_t *px, Double_t *) | |
125 | { | |
126 | // | |
127 | // PT-PARAMETERIZATION CDF, PRL 61(88) 1819 | |
128 | // POWER LAW FOR PT > 500 MEV | |
129 | // MT SCALING BELOW (T=160 MEV) | |
130 | // | |
131 | const Double_t kp0 = 1.3; | |
132 | const Double_t kxn = 8.28; | |
133 | const Double_t kxlim=0.5; | |
134 | const Double_t kt=0.160; | |
135 | const Double_t kxmpi=0.139; | |
136 | const Double_t kb=1.; | |
137 | Double_t y, y1, xmpi2, ynorm, a; | |
138 | Double_t x=*px; | |
139 | // | |
140 | y1=TMath::Power(kp0/(kp0+kxlim),kxn); | |
141 | xmpi2=kxmpi*kxmpi; | |
142 | ynorm=kb*(TMath::Exp(-sqrt(kxlim*kxlim+xmpi2)/kt)); | |
143 | a=ynorm/y1; | |
144 | if (x > kxlim) | |
145 | y=a*TMath::Power(kp0/(kp0+x),kxn); | |
146 | else | |
147 | y=kb*TMath::Exp(-sqrt(x*x+xmpi2)/kt); | |
148 | return y*x; | |
149 | } | |
150 | ||
151 | //_____________________________________________________________________________ | |
152 | static Double_t ptscal(Double_t pt, Int_t np) | |
153 | { | |
154 | // SCALING EN MASSE PAR RAPPORT A PTPI | |
155 | // MASS PI,K,ETA,RHO,OMEGA,ETA',PHI | |
156 | const Double_t khm[10] = {.13957,.493,.5488,.769,.7826,.958,1.02,0,0,0}; | |
157 | // VALUE MESON/PI AT 5 GEV | |
158 | const Double_t kfmax[10]={1.,0.3,0.55,1.0,1.0,1.0,1.0,0,0,0}; | |
159 | np--; | |
160 | Double_t f5=TMath::Power((( | |
161 | sqrt(100.018215)+2.)/(sqrt(100.+khm[np]*khm[np])+2.0)),12.3); | |
162 | Double_t fmax2=f5/kfmax[np]; | |
163 | // PIONS | |
164 | Double_t ptpion=100.*ptpi(&pt, (Double_t*) 0); | |
165 | Double_t fmtscal=TMath::Power((( | |
166 | sqrt(pt*pt+0.018215)+2.)/ (sqrt(pt*pt+khm[np]*khm[np])+2.0)),12.3)/ | |
167 | fmax2; | |
168 | return fmtscal*ptpion; | |
169 | } | |
170 | ||
171 | //_____________________________________________________________________________ | |
172 | static Double_t ptka( Double_t *px, Double_t *) | |
173 | { | |
174 | // | |
175 | // pt parametrisation for k | |
176 | // | |
177 | return ptscal(*px,2); | |
178 | } | |
179 | ||
180 | ||
181 | //_____________________________________________________________________________ | |
182 | static Double_t etapic( Double_t *py, Double_t *) | |
183 | { | |
184 | // | |
185 | // eta parametrisation for pi | |
186 | // | |
187 | const Double_t ka1 = 4913.; | |
188 | const Double_t ka2 = 1819.; | |
189 | const Double_t keta1 = 0.22; | |
190 | const Double_t keta2 = 3.66; | |
191 | const Double_t kdeta1 = 1.47; | |
192 | const Double_t kdeta2 = 1.51; | |
193 | Double_t y=TMath::Abs(*py); | |
194 | // | |
195 | Double_t ex1 = (y-keta1)*(y-keta1)/(2*kdeta1*kdeta1); | |
196 | Double_t ex2 = (y-keta2)*(y-keta2)/(2*kdeta2*kdeta2); | |
197 | return ka1*TMath::Exp(-ex1)+ka2*TMath::Exp(-ex2); | |
198 | } | |
199 | ||
200 | //_____________________________________________________________________________ | |
201 | static Double_t etakac( Double_t *py, Double_t *) | |
202 | { | |
203 | // | |
204 | // eta parametrisation for ka | |
205 | // | |
206 | const Double_t ka1 = 497.6; | |
207 | const Double_t ka2 = 215.6; | |
208 | const Double_t keta1 = 0.79; | |
209 | const Double_t keta2 = 4.09; | |
210 | const Double_t kdeta1 = 1.54; | |
211 | const Double_t kdeta2 = 1.40; | |
212 | Double_t y=TMath::Abs(*py); | |
213 | // | |
214 | Double_t ex1 = (y-keta1)*(y-keta1)/(2*kdeta1*kdeta1); | |
215 | Double_t ex2 = (y-keta2)*(y-keta2)/(2*kdeta2*kdeta2); | |
216 | return ka1*TMath::Exp(-ex1)+ka2*TMath::Exp(-ex2); | |
217 | } | |
218 | ||
219 | //_____________________________________________________________________________ | |
220 | AliGenHIJINGpara::AliGenHIJINGpara() | |
221 | :AliGenerator() | |
222 | { | |
223 | // | |
224 | // Default constructor | |
225 | // | |
1e66857c | 226 | fPtpi = 0; |
227 | fPtka = 0; | |
228 | fETApic = 0; | |
229 | fETAkac = 0; | |
230 | fDecayer = 0; | |
231 | fNt = -1; | |
971816d4 | 232 | SetCutVertexZ(); |
6b236b6f | 233 | SetPtRange(); |
2067f62c | 234 | SetPi0Decays(); |
790bbabf | 235 | } |
236 | ||
237 | //_____________________________________________________________________________ | |
238 | AliGenHIJINGpara::AliGenHIJINGpara(Int_t npart) | |
239 | :AliGenerator(npart) | |
240 | { | |
241 | // | |
242 | // Standard constructor | |
243 | // | |
244 | fName="HIGINGpara"; | |
245 | fTitle="HIJING Parametrisation Particle Generator"; | |
1e66857c | 246 | fPtpi = 0; |
247 | fPtka = 0; | |
248 | fETApic = 0; | |
249 | fETAkac = 0; | |
250 | fDecayer = 0; | |
251 | fNt = -1; | |
971816d4 | 252 | SetCutVertexZ(); |
6b236b6f | 253 | SetPtRange(); |
2067f62c | 254 | SetPi0Decays(); |
790bbabf | 255 | } |
256 | ||
257 | //_____________________________________________________________________________ | |
258 | AliGenHIJINGpara::~AliGenHIJINGpara() | |
259 | { | |
260 | // | |
261 | // Standard destructor | |
262 | // | |
263 | delete fPtpi; | |
264 | delete fPtka; | |
265 | delete fETApic; | |
266 | delete fETAkac; | |
267 | } | |
268 | ||
269 | //_____________________________________________________________________________ | |
270 | void AliGenHIJINGpara::Init() | |
271 | { | |
272 | // | |
273 | // Initialise the HIJING parametrisation | |
274 | // | |
275 | Float_t etaMin =-TMath::Log(TMath::Tan( | |
276 | TMath::Min((Double_t)fThetaMax/2,TMath::Pi()/2-1.e-10))); | |
277 | Float_t etaMax = -TMath::Log(TMath::Tan( | |
278 | TMath::Max((Double_t)fThetaMin/2,1.e-10))); | |
f25521b2 | 279 | fPtpi = new TF1("ptpi",&ptpi,0,20,0); |
280 | fPtka = new TF1("ptka",&ptka,0,20,0); | |
790bbabf | 281 | fETApic = new TF1("etapic",&etapic,etaMin,etaMax,0); |
282 | fETAkac = new TF1("etakac",&etakac,etaMin,etaMax,0); | |
f25521b2 | 283 | |
aecf26a3 | 284 | TF1 etaPic0("etapic",&etapic,-7,7,0); |
285 | TF1 etaKac0("etakac",&etakac,-7,7,0); | |
f25521b2 | 286 | |
aecf26a3 | 287 | TF1 ptPic0("ptpi",&ptpi,0.,15.,0); |
288 | TF1 ptKac0("ptka",&ptka,0.,15.,0); | |
f25521b2 | 289 | |
aecf26a3 | 290 | Float_t intETApi = etaPic0.Integral(-0.5, 0.5); |
291 | Float_t intETAka = etaKac0.Integral(-0.5, 0.5); | |
f25521b2 | 292 | Float_t scalePi = 7316/(intETApi/1.5); |
293 | Float_t scaleKa = 684/(intETAka/2.0); | |
294 | ||
295 | // Fraction of events corresponding to the selected pt-range | |
aecf26a3 | 296 | Float_t intPt = (0.877*ptPic0.Integral(0, 15)+ |
297 | 0.123*ptKac0.Integral(0, 15)); | |
298 | Float_t intPtSel = (0.877*ptPic0.Integral(fPtMin, fPtMax)+ | |
299 | 0.123*ptKac0.Integral(fPtMin, fPtMax)); | |
f25521b2 | 300 | Float_t ptFrac = intPtSel/intPt; |
301 | ||
302 | // Fraction of events corresponding to the selected eta-range | |
aecf26a3 | 303 | Float_t intETASel = (scalePi*etaPic0.Integral(etaMin, etaMax)+ |
304 | scaleKa*etaKac0.Integral(etaMin, etaMax)); | |
f25521b2 | 305 | // Fraction of events corresponding to the selected phi-range |
306 | Float_t phiFrac = (fPhiMax-fPhiMin)/2/TMath::Pi(); | |
307 | ||
308 | fParentWeight = Float_t(fNpart)/(intETASel*ptFrac*phiFrac); | |
790bbabf | 309 | |
9e1a0ddb | 310 | printf("%s: The number of particles in the selected kinematic region corresponds to %f percent of a full event\n ", |
311 | ClassName(),100.*fParentWeight); | |
5b0e4c0f | 312 | |
313 | // Issue warning message if etaMin or etaMax are outside the alowed range | |
314 | // of the parametrization | |
315 | if (etaMin < -8.001 || etaMax > 8.001) { | |
316 | printf("\n \n WARNING FROM AliGenHIJINGPara !"); | |
317 | printf("\n YOU ARE USING THE PARAMETERISATION OUTSIDE "); | |
318 | printf("\n THE ALLOWED PSEUDORAPIDITY RANGE (-8. - 8.)"); | |
319 | printf("\n YOUR LIMITS: %f %f \n \n ", etaMin, etaMax); | |
320 | } | |
2067f62c | 321 | // |
322 | // | |
323 | if (fPi0Decays) fDecayer = new AliDecayerPythia(); | |
790bbabf | 324 | } |
325 | ||
2067f62c | 326 | |
790bbabf | 327 | //_____________________________________________________________________________ |
328 | void AliGenHIJINGpara::Generate() | |
329 | { | |
330 | // | |
331 | // Generate one trigger | |
332 | // | |
333 | ||
334 | ||
335 | const Float_t kRaKpic=0.14; | |
336 | const Float_t kBorne=1/(1+kRaKpic); | |
337 | Float_t polar[3]= {0,0,0}; | |
338 | // | |
339 | const Int_t kPions[3] = {kPi0, kPiPlus, kPiMinus}; | |
340 | const Int_t kKaons[4] = {kK0Long, kK0Short, kKPlus, kKMinus}; | |
341 | // | |
342 | Float_t origin[3]; | |
343 | Float_t pt, pl, ptot; | |
344 | Float_t phi, theta; | |
345 | Float_t p[3]; | |
1e66857c | 346 | Int_t i, part, j; |
790bbabf | 347 | // |
348 | TF1 *ptf; | |
349 | TF1 *etaf; | |
350 | // | |
351 | Float_t random[6]; | |
352 | // | |
353 | for (j=0;j<3;j++) origin[j]=fOrigin[j]; | |
971816d4 | 354 | |
355 | if(fVertexSmear == kPerEvent) { | |
356 | Float_t dv[3]; | |
357 | dv[2] = 1.e10; | |
358 | while(TMath::Abs(dv[2]) > fCutVertexZ*fOsigma[2]) { | |
359 | Rndm(random,6); | |
360 | for (j=0; j < 3; j++) { | |
361 | dv[j] = fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())* | |
362 | TMath::Sqrt(-2*TMath::Log(random[2*j+1])); | |
363 | } | |
790bbabf | 364 | } |
971816d4 | 365 | for (j=0; j < 3; j++) origin[j] += dv[j]; |
366 | } // if kPerEvent | |
367 | TArrayF eventVertex; | |
368 | eventVertex.Set(3); | |
369 | eventVertex[0] = origin[0]; | |
370 | eventVertex[1] = origin[1]; | |
371 | eventVertex[2] = origin[2]; | |
372 | ||
790bbabf | 373 | for(i=0;i<fNpart;i++) { |
374 | while(1) { | |
65fb704d | 375 | Rndm(random,3); |
790bbabf | 376 | if(random[0]<kBorne) { |
377 | part=kPions[Int_t (random[1]*3)]; | |
378 | ptf=fPtpi; | |
2067f62c | 379 | etaf=fETApic; |
790bbabf | 380 | } else { |
381 | part=kKaons[Int_t (random[1]*4)]; | |
382 | ptf=fPtka; | |
383 | etaf=fETAkac; | |
384 | } | |
385 | phi=fPhiMin+random[2]*(fPhiMax-fPhiMin); | |
386 | theta=2*TMath::ATan(TMath::Exp(-etaf->GetRandom())); | |
387 | if(theta<fThetaMin || theta>fThetaMax) continue; | |
388 | pt=ptf->GetRandom(); | |
389 | pl=pt/TMath::Tan(theta); | |
390 | ptot=TMath::Sqrt(pt*pt+pl*pl); | |
391 | if(ptot<fPMin || ptot>fPMax) continue; | |
392 | p[0]=pt*TMath::Cos(phi); | |
393 | p[1]=pt*TMath::Sin(phi); | |
394 | p[2]=pl; | |
aee8290b | 395 | if(fVertexSmear==kPerTrack) { |
65fb704d | 396 | Rndm(random,6); |
790bbabf | 397 | for (j=0;j<3;j++) { |
398 | origin[j]=fOrigin[j]+fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())* | |
399 | TMath::Sqrt(-2*TMath::Log(random[2*j+1])); | |
400 | } | |
401 | } | |
1ef5f15d | 402 | if (part == kPi0 && fPi0Decays){ |
2067f62c | 403 | // |
404 | // Decay pi0 if requested | |
1e66857c | 405 | SetTrack(0,-1,part,p,origin,polar,0,kPPrimary,fNt,fParentWeight); |
406 | KeepTrack(fNt); | |
1ef5f15d | 407 | DecayPi0(origin, p); |
408 | } else { | |
1e66857c | 409 | SetTrack(fTrackIt,-1,part,p,origin,polar,0,kPPrimary,fNt,fParentWeight); |
410 | KeepTrack(fNt); | |
1ef5f15d | 411 | } |
412 | ||
790bbabf | 413 | break; |
414 | } | |
1e66857c | 415 | SetHighWaterMark(fNt); |
790bbabf | 416 | } |
1e66857c | 417 | // |
418 | ||
971816d4 | 419 | // Header |
420 | AliGenEventHeader* header = new AliGenEventHeader("HIJINGparam"); | |
421 | // Event Vertex | |
422 | header->SetPrimaryVertex(eventVertex); | |
423 | gAlice->SetGenEventHeader(header); | |
790bbabf | 424 | } |
425 | ||
426 | AliGenHIJINGpara& AliGenHIJINGpara::operator=(const AliGenHIJINGpara& rhs) | |
427 | { | |
428 | // Assignment operator | |
429 | return *this; | |
430 | } | |
431 | ||
6b236b6f | 432 | void AliGenHIJINGpara::SetPtRange(Float_t ptmin, Float_t ptmax) { |
2067f62c | 433 | AliGenerator::SetPtRange(ptmin, ptmax); |
6b236b6f | 434 | } |
790bbabf | 435 | |
2067f62c | 436 | void AliGenHIJINGpara::DecayPi0(Float_t* orig, Float_t * p) |
437 | { | |
438 | // | |
439 | // Decay the pi0 | |
440 | // and put decay products on the stack | |
441 | // | |
442 | static TClonesArray *particles; | |
443 | if(!particles) particles = new TClonesArray("TParticle",1000); | |
444 | // | |
445 | const Float_t kMass = TDatabasePDG::Instance()->GetParticle(kPi0)->Mass(); | |
56fcdfe6 | 446 | Float_t e = TMath::Sqrt(p[0] * p[0] + p[1] * p[1] + p[2] * p[2]+ kMass * kMass); |
2067f62c | 447 | // |
448 | // Decay the pi0 | |
449 | TLorentzVector pmom(p[0], p[1], p[2], e); | |
450 | fDecayer->Decay(kPi0, &pmom); | |
56fcdfe6 | 451 | |
2067f62c | 452 | // |
453 | // Put decay particles on the stack | |
454 | // | |
2067f62c | 455 | Float_t polar[3] = {0., 0., 0.}; |
456 | Int_t np = fDecayer->ImportParticles(particles); | |
1e66857c | 457 | Int_t nt; |
2067f62c | 458 | for (Int_t i = 1; i < np; i++) |
459 | { | |
7b33c00a | 460 | TParticle* iParticle = (TParticle *) particles->At(i); |
461 | p[0] = iParticle->Px(); | |
462 | p[1] = iParticle->Py(); | |
463 | p[2] = iParticle->Pz(); | |
2067f62c | 464 | Int_t part = iParticle->GetPdgCode(); |
1e66857c | 465 | |
466 | SetTrack(fTrackIt, fNt, part, p, orig, polar, 0, kPDecay, nt, fParentWeight); | |
467 | KeepTrack(nt); | |
2067f62c | 468 | } |
1e66857c | 469 | fNt = nt; |
2067f62c | 470 | } |