1 /**************************************************************************
2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
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 **************************************************************************/
18 Revision 1.9 2000/06/14 15:20:56 morsch
21 Revision 1.8 2000/06/09 20:32:11 morsch
22 All coding rule violations except RS3 corrected
24 Revision 1.7 2000/05/02 08:12:13 morsch
25 Coding rule violations corrected.
27 Revision 1.6 1999/09/29 09:24:14 fca
28 Introduction of the Copyright and cvs Log
32 #include "AliGenMUONlib.h"
35 ClassImp(AliGenMUONlib)
38 Double_t AliGenMUONlib::PtPion(Double_t *px, Double_t *dummy)
41 // PT-PARAMETERIZATION CDF, PRL 61(88) 1819
42 // POWER LAW FOR PT > 500 MEV
43 // MT SCALING BELOW (T=160 MEV)
45 const Double_t kp0 = 1.3;
46 const Double_t kxn = 8.28;
47 const Double_t kxlim=0.5;
48 const Double_t kt=0.160;
49 const Double_t kxmpi=0.139;
51 Double_t y, y1, xmpi2, ynorm, a;
54 y1=TMath::Power(kp0/(kp0+kxlim),kxn);
56 ynorm=kb*(TMath::Exp(-sqrt(kxlim*kxlim+xmpi2)/kt));
59 y=a*TMath::Power(kp0/(kp0+x),kxn);
61 y=kb*TMath::Exp(-sqrt(x*x+xmpi2)/kt);
67 Double_t AliGenMUONlib::YPion( Double_t *py, Double_t *dummy)
70 const Double_t ka = 7000.;
71 const Double_t kdy = 4.;
73 Double_t y=TMath::Abs(*py);
75 Double_t ex = y*y/(2*kdy*kdy);
76 return ka*TMath::Exp(-ex);
78 // particle composition
80 Int_t AliGenMUONlib::IpPion()
85 if (random[0] < 0.5) {
92 //____________________________________________________________
96 Double_t AliGenMUONlib::PtScal(Double_t pt, Int_t np)
98 // SCALING EN MASSE PAR RAPPORT A PTPI
99 // MASS PI,K,ETA,RHO,OMEGA,ETA',PHI
100 const Double_t khm[10] = {.13957,.493,.5488,.769,.7826,.958,1.02,0,0,0};
101 // VALUE MESON/PI AT 5 GEV
102 const Double_t kfmax[10]={1.,0.3,0.55,1.0,1.0,1.0,1.0,0,0,0};
104 Double_t f5=TMath::Power(((sqrt(100.018215)+2.)/(sqrt(100.+khm[np]*khm[np])+2.0)),12.3);
105 Double_t fmax2=f5/kfmax[np];
107 Double_t ptpion=100.*PtPion(&pt, (Double_t*) 0);
108 Double_t fmtscal=TMath::Power(((sqrt(pt*pt+0.018215)+2.)/
109 (sqrt(pt*pt+khm[np]*khm[np])+2.0)),12.3)/ fmax2;
110 return fmtscal*ptpion;
116 //____________________________________________________________
117 Double_t AliGenMUONlib::PtKaon( Double_t *px, Double_t *dummy)
120 return PtScal(*px,2);
124 //____________________________________________________________
125 Double_t AliGenMUONlib::YKaon( Double_t *py, Double_t *dummy)
128 const Double_t ka = 1000.;
129 const Double_t kdy = 4.;
132 Double_t y=TMath::Abs(*py);
134 Double_t ex = y*y/(2*kdy*kdy);
135 return ka*TMath::Exp(-ex);
138 // particle composition
140 Int_t AliGenMUONlib::IpKaon()
145 if (random[0] < 0.5) {
156 //____________________________________________________________
157 Double_t AliGenMUONlib::PtJpsi( Double_t *px, Double_t *dummy)
160 const Double_t kpt0 = 4.;
161 const Double_t kxn = 3.6;
164 Double_t pass1 = 1.+(x/kpt0)*(x/kpt0);
165 return x/TMath::Power(pass1,kxn);
169 //____________________________________________________________
170 Double_t AliGenMUONlib::YJpsi(Double_t *py, Double_t *dummy)
173 const Double_t ky0 = 4.;
174 const Double_t kb=1.;
176 Double_t y=TMath::Abs(*py);
181 yj=kb*TMath::Exp(-(y-ky0)*(y-ky0)/2);
184 // particle composition
186 Int_t AliGenMUONlib::IpJpsi()
196 //____________________________________________________________
197 Double_t AliGenMUONlib::PtUpsilon( Double_t *px, Double_t *dummy )
200 const Double_t kpt0 = 5.3;
201 const Double_t kxn = 2.5;
204 Double_t pass1 = 1.+(x/kpt0)*(x/kpt0);
205 return x/TMath::Power(pass1,kxn);
210 //____________________________________________________________
211 Double_t AliGenMUONlib::YUpsilon(Double_t *py, Double_t *dummy)
214 const Double_t ky0 = 3.;
215 const Double_t kb=1.;
217 Double_t y=TMath::Abs(*py);
222 yu=kb*TMath::Exp(-(y-ky0)*(y-ky0)/2);
225 // particle composition
227 Int_t AliGenMUONlib::IpUpsilon()
237 // pt-distribution (by scaling of pion distribution)
238 //____________________________________________________________
239 Double_t AliGenMUONlib::PtPhi( Double_t *px, Double_t *dummy)
242 return PtScal(*px,7);
245 Double_t AliGenMUONlib::YPhi( Double_t *px, Double_t *dummy)
249 return YJpsi(px,dum);
251 // particle composition
253 Int_t AliGenMUONlib::IpPhi()
264 //____________________________________________________________
265 Double_t AliGenMUONlib::PtCharm( Double_t *px, Double_t *dummy)
268 const Double_t kpt0 = 4.08;
269 const Double_t kxn = 9.40;
272 Double_t pass1 = 1.+(x/kpt0)*(x/kpt0);
273 return x/TMath::Power(pass1,kxn);
276 Double_t AliGenMUONlib::YCharm( Double_t *px, Double_t *dummy)
280 return YJpsi(px,dum);
283 Int_t AliGenMUONlib::IpCharm()
290 if (random[0] < 0.5) {
292 } else if (random[0] < 0.75) {
294 } else if (random[0] < 0.90) {
299 if (random[1] < 0.5) {ip=-ip;}
310 //____________________________________________________________
311 Double_t AliGenMUONlib::PtBeauty( Double_t *px, Double_t *dummy)
314 const Double_t kpt0 = 4.;
315 const Double_t kxn = 3.6;
318 Double_t pass1 = 1.+(x/kpt0)*(x/kpt0);
319 return x/TMath::Power(pass1,kxn);
322 Double_t AliGenMUONlib::YBeauty( Double_t *px, Double_t *dummy)
326 return YJpsi(px,dum);
329 Int_t AliGenMUONlib::IpBeauty()
331 // Beauty Composition
335 if (random[0] < 0.5) {
337 } else if (random[0] < 0.75) {
339 } else if (random[0] < 0.90) {
344 if (random[1] < 0.5) {ip=-ip;}
349 typedef Double_t (*GenFunc) (Double_t*, Double_t*);
350 GenFunc AliGenMUONlib::GetPt(Param_t param, const char* tname)
352 // Return pointer to pT parameterisation
379 printf("<AliGenMUONlib::GetPt> unknown parametrisation\n");
384 GenFunc AliGenMUONlib::GetY(Param_t param, const char* tname)
386 // Return pointer to y- parameterisation
413 printf("<AliGenMUONlib::GetY> unknown parametrisation\n");
417 typedef Int_t (*GenFuncIp) ();
418 GenFuncIp AliGenMUONlib::GetIp(Param_t param, const char* tname)
420 // Return pointer to particle type parameterisation
447 printf("<AliGenMUONlib::GetIp> unknown parametrisation\n");