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 1.18 2002/11/07 09:13:42 morsch
19 Use "Vogt" to label new distributions.
21 Revision 1.17 2002/11/07 09:06:10 morsch
22 J/Psi and Upsilon pt and y distributions from R. Vogt 2002 added.
24 Revision 1.16 2002/10/14 14:55:35 hristov
25 Merging the VirtualMC branch to the main development branch (HEAD)
27 Revision 1.14.6.1 2002/06/10 14:57:41 hristov
30 Revision 1.15 2002/04/17 10:11:51 morsch
31 Coding Rule violations corrected.
33 Revision 1.14 2002/02/22 17:26:43 morsch
36 Revision 1.13 2001/03/27 11:01:04 morsch
37 Charm pt-distribution corrected. More realistic y-distribution for pi and K.
39 Revision 1.12 2001/03/09 13:01:41 morsch
40 - enum constants for paramterisation type (particle family) moved to AliGen*lib.h
41 - use AliGenGSIlib::kUpsilon, AliGenPHOSlib::kEtaPrime to access the constants
43 Revision 1.11 2000/11/30 07:12:50 alibrary
44 Introducing new Rndm and QA classes
46 Revision 1.10 2000/06/29 21:08:27 morsch
47 All paramatrisation libraries derive from the pure virtual base class AliGenLib.
48 This allows to pass a pointer to a library directly to AliGenParam and avoids the
49 use of function pointers in Config.C.
51 Revision 1.9 2000/06/14 15:20:56 morsch
54 Revision 1.8 2000/06/09 20:32:11 morsch
55 All coding rule violations except RS3 corrected
57 Revision 1.7 2000/05/02 08:12:13 morsch
58 Coding rule violations corrected.
60 Revision 1.6 1999/09/29 09:24:14 fca
61 Introduction of the Copyright and cvs Log
65 // Library class for particle pt and y distributions used for
66 // muon spectrometer simulations.
67 // To be used with AliGenParam.
68 // The following particle typed can be simulated:
69 // pi, K, phi, omega, eta, J/Psi, Upsilon, charm and beauty mesons.
71 // andreas.morsch@cern.ch
77 #include "AliGenMUONlib.h"
79 ClassImp(AliGenMUONlib)
82 Double_t AliGenMUONlib::PtPion(Double_t *px, Double_t *dummy)
85 // PT-PARAMETERIZATION CDF, PRL 61(88) 1819
86 // POWER LAW FOR PT > 500 MEV
87 // MT SCALING BELOW (T=160 MEV)
89 const Double_t kp0 = 1.3;
90 const Double_t kxn = 8.28;
91 const Double_t kxlim=0.5;
92 const Double_t kt=0.160;
93 const Double_t kxmpi=0.139;
95 Double_t y, y1, xmpi2, ynorm, a;
98 y1=TMath::Power(kp0/(kp0+kxlim),kxn);
100 ynorm=kb*(TMath::Exp(-sqrt(kxlim*kxlim+xmpi2)/kt));
103 y=a*TMath::Power(kp0/(kp0+x),kxn);
105 y=kb*TMath::Exp(-sqrt(x*x+xmpi2)/kt);
111 Double_t AliGenMUONlib::YPion( Double_t *py, Double_t *dummy)
114 Double_t y=TMath::Abs(*py);
116 const Double_t ka = 7000.;
117 const Double_t kdy = 4.;
118 Double_t ex = y*y/(2*kdy*kdy);
119 return ka*TMath::Exp(-ex);
121 return 1.16526e+04+y*-3.79886e+03+y*y*4.31130e+02;
124 // particle composition
126 Int_t AliGenMUONlib::IpPion(TRandom *ran)
129 if (ran->Rndm() < 0.5) {
136 //____________________________________________________________
140 Double_t AliGenMUONlib::PtScal(Double_t pt, Int_t np)
142 // SCALING EN MASSE PAR RAPPORT A PTPI
143 // MASS PI,K,ETA,RHO,OMEGA,ETA',PHI
144 const Double_t khm[10] = {.13957,.493,.5488,.769,.7826,.958,1.02,0,0,0};
145 // VALUE MESON/PI AT 5 GEV
146 const Double_t kfmax[10]={1.,0.3,0.55,1.0,1.0,1.0,1.0,0,0,0};
148 Double_t f5=TMath::Power(((sqrt(100.018215)+2.)/(sqrt(100.+khm[np]*khm[np])+2.0)),12.3);
149 Double_t fmax2=f5/kfmax[np];
151 Double_t ptpion=100.*PtPion(&pt, (Double_t*) 0);
152 Double_t fmtscal=TMath::Power(((sqrt(pt*pt+0.018215)+2.)/
153 (sqrt(pt*pt+khm[np]*khm[np])+2.0)),12.3)/ fmax2;
154 return fmtscal*ptpion;
160 //____________________________________________________________
161 Double_t AliGenMUONlib::PtKaon( Double_t *px, Double_t *dummy)
164 return PtScal(*px,2);
168 //____________________________________________________________
169 Double_t AliGenMUONlib::YKaon( Double_t *py, Double_t *dummy)
172 Double_t y=TMath::Abs(*py);
174 const Double_t ka = 1000.;
175 const Double_t kdy = 4.;
177 Double_t ex = y*y/(2*kdy*kdy);
178 return ka*TMath::Exp(-ex);
181 return 1.16526e+04+y*-3.79886e+03+y*y*4.31130e+02;
184 // particle composition
186 Int_t AliGenMUONlib::IpKaon(TRandom *ran)
189 if (ran->Rndm() < 0.5) {
200 //____________________________________________________________
201 Double_t AliGenMUONlib::PtJpsi( Double_t *px, Double_t *dummy)
204 const Double_t kpt0 = 4.;
205 const Double_t kxn = 3.6;
208 Double_t pass1 = 1.+(x/kpt0)*(x/kpt0);
209 return x/TMath::Power(pass1,kxn);
212 Double_t AliGenMUONlib::PtJpsiPbPb( Double_t *px, Double_t *dummy)
219 // mc = 1.4 GeV, pt-kick 1 GeV
223 -2.13098e+00, 9.46552e+00, -5.06799e+00, 1.27260e+00,
224 -1.83806e-01, 1.55853e-02, -7.23241e-04, 1.42105e-05
228 Double_t y = c[j = 7];
229 while (j > 0) y = y * x +c[--j];
230 y = x * TMath::Exp(y);
235 //____________________________________________________________
236 Double_t AliGenMUONlib::YJpsi(Double_t *py, Double_t *dummy)
239 const Double_t ky0 = 4.;
240 const Double_t kb=1.;
242 Double_t y=TMath::Abs(*py);
247 yj=kb*TMath::Exp(-(y-ky0)*(y-ky0)/2);
252 Double_t AliGenMUONlib::YJpsiPbPb( Double_t *px, Double_t *dummy)
262 // mc = 1.4 GeV, pt-kick 1 GeV
264 Double_t c[5] = {-6.03425e+02, 4.98257e+02, -1.38794e+02, 1.62209e+01, -6.85955e-01};
265 Double_t x = TMath::Abs(px[0]);
273 while (j > 0) y = y * x + c[--j];
281 // particle composition
283 Int_t AliGenMUONlib::IpJpsi(TRandom *)
293 //____________________________________________________________
294 Double_t AliGenMUONlib::PtUpsilon( Double_t *px, Double_t *dummy )
297 const Double_t kpt0 = 5.3;
298 const Double_t kxn = 2.5;
301 Double_t pass1 = 1.+(x/kpt0)*(x/kpt0);
302 return x/TMath::Power(pass1,kxn);
305 Double_t AliGenMUONlib::PtUpsilonPbPb( Double_t *px, Double_t *dummy)
315 // mc = 1.4 GeV, pt-kick 1 GeV
319 -1.03488e+01, 1.28065e+01, -6.60500e+00, 1.66140e+00,
320 -2.34293e-01, 1.86925e-02, -7.80708e-04, 1.30610e-05
323 Double_t y = c[j = 7];
324 while (j > 0) y = y * x +c[--j];
325 y = x * TMath::Exp(y);
332 //____________________________________________________________
333 Double_t AliGenMUONlib::YUpsilon(Double_t *py, Double_t *dummy)
336 const Double_t ky0 = 3.;
337 const Double_t kb=1.;
339 Double_t y=TMath::Abs(*py);
344 yu=kb*TMath::Exp(-(y-ky0)*(y-ky0)/2);
349 Double_t AliGenMUONlib::YUpsilonPbPb( Double_t *px, Double_t *dummy)
359 // mc = 1.4 GeV, pt-kick 1 GeV
362 Double_t c[7] = {3.40036e-01, -3.98882e-07, -4.48398e-03, 8.46411e-08, -6.10854e-04,
363 -2.99753e-09, 1.28895e-05};
366 if (TMath::Abs(x) > 5.55) return 0.;
368 Double_t y = c[j = 6];
369 while (j > 0) y = y * x +c[--j];
373 // particle composition
375 Int_t AliGenMUONlib::IpUpsilon(TRandom *)
385 // pt-distribution (by scaling of pion distribution)
386 //____________________________________________________________
387 Double_t AliGenMUONlib::PtPhi( Double_t *px, Double_t *dummy)
390 return PtScal(*px,7);
393 Double_t AliGenMUONlib::YPhi( Double_t *px, Double_t *dummy)
397 return YJpsi(px,dum);
399 // particle composition
401 Int_t AliGenMUONlib::IpPhi(TRandom *)
411 // pt-distribution (by scaling of pion distribution)
412 //____________________________________________________________
413 Double_t AliGenMUONlib::PtOmega( Double_t *px, Double_t *dummy)
416 return PtScal(*px,5);
419 Double_t AliGenMUONlib::YOmega( Double_t *px, Double_t *dummy)
423 return YJpsi(px,dum);
425 // particle composition
427 Int_t AliGenMUONlib::IpOmega(TRandom *)
438 // pt-distribution (by scaling of pion distribution)
439 //____________________________________________________________
440 Double_t AliGenMUONlib::PtEta( Double_t *px, Double_t *dummy)
443 return PtScal(*px,3);
446 Double_t AliGenMUONlib::YEta( Double_t *px, Double_t *dummy)
450 return YJpsi(px,dum);
452 // particle composition
454 Int_t AliGenMUONlib::IpEta(TRandom *)
465 //____________________________________________________________
466 Double_t AliGenMUONlib::PtCharm( Double_t *px, Double_t *dummy)
469 const Double_t kpt0 = 4.08;
470 const Double_t kxn = 9.40;
474 Double_t pass1 = 1.+(x/kpt0);
475 return x/TMath::Power(pass1,kxn);
478 Double_t AliGenMUONlib::YCharm( Double_t *px, Double_t *dummy)
482 return YJpsi(px,dum);
485 Int_t AliGenMUONlib::IpCharm(TRandom *ran)
491 random = ran->Rndm();
494 } else if (random < 0.75) {
496 } else if (random < 0.90) {
501 if (ran->Rndm() < 0.5) {ip=-ip;}
512 //____________________________________________________________
513 Double_t AliGenMUONlib::PtBeauty( Double_t *px, Double_t *dummy)
516 const Double_t kpt0 = 4.;
517 const Double_t kxn = 3.6;
520 Double_t pass1 = 1.+(x/kpt0)*(x/kpt0);
521 return x/TMath::Power(pass1,kxn);
524 Double_t AliGenMUONlib::YBeauty( Double_t *px, Double_t *dummy)
528 return YJpsi(px,dum);
531 Int_t AliGenMUONlib::IpBeauty(TRandom *ran)
533 // Beauty Composition
536 random = ran->Rndm();
539 } else if (random < 0.75) {
541 } else if (random < 0.90) {
546 if (ran->Rndm() < 0.5) {ip=-ip;}
551 typedef Double_t (*GenFunc) (Double_t*, Double_t*);
552 GenFunc AliGenMUONlib::GetPt(Int_t param, const char* tname) const
554 // Return pointer to pT parameterisation
555 TString sname = TString(tname);
569 if (sname == "Vogt") {
576 if (sname == "Vogt") {
596 printf("<AliGenMUONlib::GetPt> unknown parametrisation\n");
601 GenFunc AliGenMUONlib::GetY(Int_t param, const char* tname) const
603 TString sname = TString(tname);
605 // Return pointer to y- parameterisation
619 if (sname == "Vogt") {
626 if (sname == "Vogt") {
646 printf("<AliGenMUONlib::GetY> unknown parametrisation\n");
650 typedef Int_t (*GenFuncIp) (TRandom *);
651 GenFuncIp AliGenMUONlib::GetIp(Int_t param, const char* tname) const
653 // Return pointer to particle type parameterisation
686 printf("<AliGenMUONlib::GetIp> unknown parametrisation\n");
693 Float_t AliGenMUONlib::Interpolate(Float_t x, Float_t* y, Float_t x0,
698 // Neville's alorithm for interpolation
704 // n: number of data points
705 // no: order of polynom
707 Float_t* c = new Float_t[n];
708 Float_t* d = new Float_t[n];
710 for (i = 0; i < n; i++) {
715 Int_t ns = int((x - x0)/dx);
719 for (m = 0; m < no; m++) {
720 for (i = 0; i < n-m; i++) {
721 Float_t ho = x0 + Float_t(i) * dx - x;
722 Float_t hp = x0 + Float_t(i+m+1) * dx - x;
723 Float_t w = c[i+1] - d[i];
731 if (2*ns < (n-m-1)) {