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