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