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886b6f73 | 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 | $Log$ | |
b22ee262 | 18 | Revision 1.4 2000/06/14 15:21:05 morsch |
19 | Include clean-up (IH) | |
20 | ||
5c3fd7ea | 21 | Revision 1.3 2000/06/09 20:32:54 morsch |
22 | All coding rule violations except RS3 corrected | |
23 | ||
f87cfe57 | 24 | Revision 1.2 1999/11/04 11:30:48 fca |
25 | Improve comments | |
26 | ||
9ae59e17 | 27 | Revision 1.1 1999/11/03 17:43:20 fca |
28 | New version from G.Martinez & A.Morsch | |
29 | ||
886b6f73 | 30 | */ |
31 | ||
32 | //====================================================================== | |
33 | // AliGenPHOSlib class contains parameterizations of the | |
34 | // pion, kaon, eta, omega, etaprime, phi and baryon (proton, | |
35 | // antiproton, neutron and anti-neutron) particles for the | |
36 | // study of the neutral background in PHOS detector. | |
37 | // These parameterizations are used by the | |
38 | // AliGenParam class: | |
39 | // AliGenParam(npar, param, AliGenPHOSlib::GetPt(param), | |
40 | // AliGenPHOSlib::GetY(param), | |
41 | // AliGenPHOSlib::GetIp(param) ) | |
42 | // param represents the particle to be simulated : | |
43 | // Pion, Kaon, Eta, Omega, Etaprime, Phi or Baryon | |
44 | // Pt distributions are calculated from the transverse mass scaling | |
9ae59e17 | 45 | // with Pions, using the PtScal function taken from AliGenMUONlib |
886b6f73 | 46 | // version aliroot 3.01 |
47 | // | |
9ae59e17 | 48 | // Gines MARTINEZ. Laurent APHECETCHE and Yves SCHUTZ |
49 | // GPS @ SUBATECH, Nantes , France (October 1999) | |
886b6f73 | 50 | // http://www-subatech.in2p3.fr/~photons/subatech |
51 | // martinez@subatech.in2p3.fr | |
52 | //====================================================================== | |
53 | ||
54 | #include "AliGenPHOSlib.h" | |
5c3fd7ea | 55 | #include "AliMC.h" |
886b6f73 | 56 | |
57 | ClassImp(AliGenPHOSlib) | |
58 | ||
59 | //====================================================================== | |
60 | // P I O N S | |
61 | // (From GetPt, GetY and GetIp as param = Pion) | |
62 | // Transverse momentum distribution" PtPion | |
63 | // Rapidity distribution YPion | |
64 | // Particle distribution IdPion 111, 211 and -211 (pi0, pi+ and pi-) | |
65 | // | |
66 | Double_t AliGenPHOSlib::PtPion(Double_t *px, Double_t *) | |
67 | { | |
68 | // Pion transverse momentum distribtuion taken | |
9ae59e17 | 69 | // from AliGenMUONlib class, version 3.01 of aliroot |
886b6f73 | 70 | // PT-PARAMETERIZATION CDF, PRL 61(88) 1819 |
71 | // POWER LAW FOR PT > 500 MEV | |
72 | // MT SCALING BELOW (T=160 MEV) | |
73 | // | |
f87cfe57 | 74 | const Double_t kp0 = 1.3; |
75 | const Double_t kxn = 8.28; | |
76 | const Double_t kxlim=0.5; | |
77 | const Double_t kt=0.160; | |
78 | const Double_t kxmpi=0.139; | |
79 | const Double_t kb=1.; | |
80 | Double_t y, y1, kxmpi2, ynorm, a; | |
886b6f73 | 81 | Double_t x=*px; |
82 | // | |
f87cfe57 | 83 | y1=TMath::Power(kp0/(kp0+kxlim),kxn); |
84 | kxmpi2=kxmpi*kxmpi; | |
85 | ynorm=kb*(TMath::Exp(-sqrt(kxlim*kxlim+kxmpi2)/kt)); | |
886b6f73 | 86 | a=ynorm/y1; |
f87cfe57 | 87 | if (x > kxlim) |
88 | y=a*TMath::Power(kp0/(kp0+x),kxn); | |
886b6f73 | 89 | else |
f87cfe57 | 90 | y=kb*TMath::Exp(-sqrt(x*x+kxmpi2)/kt); |
886b6f73 | 91 | return y*x; |
92 | } | |
886b6f73 | 93 | Double_t AliGenPHOSlib::YPion( Double_t *py, Double_t *) |
94 | { | |
f87cfe57 | 95 | // |
96 | // pion y-distribution | |
97 | // | |
98 | ||
99 | const Double_t ka = 7000.; | |
100 | const Double_t kdy = 4.; | |
886b6f73 | 101 | |
102 | Double_t y=TMath::Abs(*py); | |
103 | // | |
f87cfe57 | 104 | Double_t ex = y*y/(2*kdy*kdy); |
105 | return ka*TMath::Exp(-ex); | |
886b6f73 | 106 | } |
f87cfe57 | 107 | |
886b6f73 | 108 | Int_t AliGenPHOSlib::IpPion() |
109 | { | |
f87cfe57 | 110 | // particle composition pi+, pi0, pi- |
111 | // | |
112 | ||
886b6f73 | 113 | Float_t random[1]; |
114 | gMC->Rndm(random,1); | |
115 | ||
116 | if ( (3.*random[0]) < 1. ) | |
117 | { | |
118 | return 211 ; | |
119 | } | |
120 | else | |
121 | { | |
122 | if ( (3.*random[0]) >= 2.) | |
123 | { | |
124 | return -211 ; | |
125 | } | |
126 | else | |
127 | { | |
128 | return 111 ; | |
129 | } | |
130 | } | |
131 | } | |
132 | // End Pions | |
133 | //============================================================= | |
134 | // | |
f87cfe57 | 135 | Double_t AliGenPHOSlib::PtScal(Double_t pt, Int_t np) |
136 | { | |
886b6f73 | 137 | // Mt-scaling |
138 | // Fonction for the calculation of the Pt distribution for a | |
139 | // given particle np, from the pion Pt distribution using the | |
140 | // mt scaling. This function was taken from AliGenMUONlib | |
141 | // aliroot version 3.01, and was extended for baryons | |
142 | // np = 1=>Pions 2=>Kaons 3=>Etas 4=>Omegas 5=>ETA' 6=>PHI | |
143 | // 7=>BARYONS-BARYONBARS | |
f87cfe57 | 144 | |
886b6f73 | 145 | // SCALING EN MASSE PAR RAPPORT A PTPI |
146 | // MASS 1=>PI, 2=>K, 3=>ETA, 4=>OMEGA, 5=>ETA',6=>PHI | |
f87cfe57 | 147 | const Double_t khm[10] = {0.1396, 0.494, 0.547, 0.782, 0.957, 1.02, |
886b6f73 | 148 | // MASS 7=>BARYON-BARYONBAR |
149 | 0.938, 0. , 0., 0.}; | |
150 | // VALUE MESON/PI AT 5 GEV | |
f87cfe57 | 151 | const Double_t kfmax[10]={1., 1., 1., 1., 1., 1., 1., 1., 1., 1.}; |
886b6f73 | 152 | np--; |
f87cfe57 | 153 | Double_t f5=TMath::Power(((sqrt(100.018215)+2.)/(sqrt(100.+khm[np]*khm[np])+2.0)),12.3); |
154 | Double_t kfmax2=f5/kfmax[np]; | |
886b6f73 | 155 | // PIONS |
156 | Double_t ptpion=100.*PtPion(&pt, (Double_t*) 0); | |
157 | Double_t fmtscal=TMath::Power(((sqrt(pt*pt+0.018215)+2.)/ | |
f87cfe57 | 158 | (sqrt(pt*pt+khm[np]*khm[np])+2.0)),12.3)/ kfmax2; |
886b6f73 | 159 | return fmtscal*ptpion; |
160 | } | |
161 | // End Scaling | |
162 | //============================================================================ | |
163 | // K A O N S | |
886b6f73 | 164 | Double_t AliGenPHOSlib::PtKaon( Double_t *px, Double_t *) |
165 | { | |
f87cfe57 | 166 | // kaon |
167 | // pt-distribution | |
168 | //____________________________________________________________ | |
169 | ||
886b6f73 | 170 | return PtScal(*px,2); // 2==> Kaon in the PtScal function |
171 | } | |
172 | ||
886b6f73 | 173 | Double_t AliGenPHOSlib::YKaon( Double_t *py, Double_t *) |
174 | { | |
f87cfe57 | 175 | // y-distribution |
176 | //____________________________________________________________ | |
177 | ||
178 | const Double_t ka = 1000.; | |
179 | const Double_t kdy = 4.; | |
886b6f73 | 180 | |
181 | ||
182 | Double_t y=TMath::Abs(*py); | |
183 | // | |
f87cfe57 | 184 | Double_t ex = y*y/(2*kdy*kdy); |
185 | return ka*TMath::Exp(-ex); | |
886b6f73 | 186 | } |
187 | ||
886b6f73 | 188 | Int_t AliGenPHOSlib::IpKaon() |
189 | { | |
f87cfe57 | 190 | // particle composition |
191 | // | |
192 | ||
886b6f73 | 193 | Float_t random[1],random2[1]; |
194 | gMC->Rndm(random,1); | |
195 | gMC->Rndm(random2,1); | |
196 | if (random2[0] < 0.5) | |
197 | { | |
198 | if (random[0] < 0.5) { | |
199 | return 321; // K+ | |
200 | } else { | |
201 | return -321; // K- | |
202 | } | |
203 | } | |
204 | else | |
205 | { | |
206 | if (random[0] < 0.5) { | |
9ae59e17 | 207 | return 130; // K^0 short |
886b6f73 | 208 | } else { |
9ae59e17 | 209 | return 310; // K^0 long |
886b6f73 | 210 | } |
211 | } | |
212 | } | |
213 | // End Kaons | |
214 | //============================================================================ | |
215 | //============================================================================ | |
216 | // E T A S | |
886b6f73 | 217 | Double_t AliGenPHOSlib::PtEta( Double_t *px, Double_t *) |
218 | { | |
f87cfe57 | 219 | // etas |
220 | // pt-distribution | |
221 | //____________________________________________________________ | |
222 | ||
886b6f73 | 223 | return PtScal(*px,3); // 3==> Eta in the PtScal function |
224 | } | |
225 | ||
886b6f73 | 226 | Double_t AliGenPHOSlib::YEta( Double_t *py, Double_t *) |
227 | { | |
f87cfe57 | 228 | // y-distribution |
229 | //____________________________________________________________ | |
230 | ||
231 | const Double_t ka = 1000.; | |
232 | const Double_t kdy = 4.; | |
886b6f73 | 233 | |
234 | ||
235 | Double_t y=TMath::Abs(*py); | |
236 | // | |
f87cfe57 | 237 | Double_t ex = y*y/(2*kdy*kdy); |
238 | return ka*TMath::Exp(-ex); | |
886b6f73 | 239 | } |
240 | ||
886b6f73 | 241 | Int_t AliGenPHOSlib::IpEta() |
242 | { | |
f87cfe57 | 243 | // particle composition |
244 | // | |
245 | ||
886b6f73 | 246 | return 221; // eta |
247 | } | |
248 | // End Etas | |
249 | //============================================================================ | |
250 | //============================================================================ | |
251 | // O M E G A S | |
f87cfe57 | 252 | Double_t AliGenPHOSlib::PtOmega( Double_t *px, Double_t *) |
253 | { | |
886b6f73 | 254 | // omegas |
255 | // pt-distribution | |
256 | //____________________________________________________________ | |
f87cfe57 | 257 | |
886b6f73 | 258 | return PtScal(*px,4); // 4==> Omega in the PtScal function |
259 | } | |
260 | ||
886b6f73 | 261 | Double_t AliGenPHOSlib::YOmega( Double_t *py, Double_t *) |
262 | { | |
f87cfe57 | 263 | // y-distribution |
264 | //____________________________________________________________ | |
265 | ||
266 | const Double_t ka = 1000.; | |
267 | const Double_t kdy = 4.; | |
886b6f73 | 268 | |
269 | ||
270 | Double_t y=TMath::Abs(*py); | |
271 | // | |
f87cfe57 | 272 | Double_t ex = y*y/(2*kdy*kdy); |
273 | return ka*TMath::Exp(-ex); | |
886b6f73 | 274 | } |
275 | ||
886b6f73 | 276 | Int_t AliGenPHOSlib::IpOmega() |
277 | { | |
f87cfe57 | 278 | // particle composition |
279 | // | |
280 | ||
886b6f73 | 281 | return 223; // Omega |
282 | } | |
283 | // End Omega | |
284 | //============================================================================ | |
285 | //============================================================================ | |
286 | // E T A P R I M E | |
f87cfe57 | 287 | Double_t AliGenPHOSlib::PtEtaprime( Double_t *px, Double_t *) |
288 | { | |
886b6f73 | 289 | // etaprime |
290 | // pt-distribution | |
291 | //____________________________________________________________ | |
f87cfe57 | 292 | |
886b6f73 | 293 | return PtScal(*px,5); // 5==> Etaprime in the PtScal function |
294 | } | |
295 | ||
886b6f73 | 296 | Double_t AliGenPHOSlib::YEtaprime( Double_t *py, Double_t *) |
297 | { | |
f87cfe57 | 298 | // y-distribution |
299 | //____________________________________________________________ | |
300 | ||
301 | const Double_t ka = 1000.; | |
302 | const Double_t kdy = 4.; | |
886b6f73 | 303 | |
304 | ||
305 | Double_t y=TMath::Abs(*py); | |
306 | // | |
f87cfe57 | 307 | Double_t ex = y*y/(2*kdy*kdy); |
308 | return ka*TMath::Exp(-ex); | |
886b6f73 | 309 | } |
310 | ||
886b6f73 | 311 | Int_t AliGenPHOSlib::IpEtaprime() |
312 | { | |
f87cfe57 | 313 | // particle composition |
314 | // | |
315 | ||
886b6f73 | 316 | return 331; // Etaprime |
317 | } | |
318 | // End EtaPrime | |
319 | //=================================================================== | |
320 | //============================================================================ | |
321 | // P H I S | |
f87cfe57 | 322 | Double_t AliGenPHOSlib::PtPhi( Double_t *px, Double_t *) |
323 | { | |
886b6f73 | 324 | // phi |
325 | // pt-distribution | |
326 | //____________________________________________________________ | |
f87cfe57 | 327 | |
886b6f73 | 328 | return PtScal(*px,6); // 6==> Phi in the PtScal function |
329 | } | |
330 | ||
886b6f73 | 331 | Double_t AliGenPHOSlib::YPhi( Double_t *py, Double_t *) |
332 | { | |
f87cfe57 | 333 | // y-distribution |
334 | //____________________________________________________________ | |
335 | ||
336 | const Double_t ka = 1000.; | |
337 | const Double_t kdy = 4.; | |
886b6f73 | 338 | |
339 | ||
340 | Double_t y=TMath::Abs(*py); | |
341 | // | |
f87cfe57 | 342 | Double_t ex = y*y/(2*kdy*kdy); |
343 | return ka*TMath::Exp(-ex); | |
886b6f73 | 344 | } |
345 | ||
f87cfe57 | 346 | Int_t AliGenPHOSlib::IpPhi() |
347 | { | |
886b6f73 | 348 | // particle composition |
349 | // | |
f87cfe57 | 350 | |
886b6f73 | 351 | return 333; // Phi |
352 | } | |
353 | // End Phis | |
354 | //=================================================================== | |
355 | //============================================================================ | |
356 | // B A R Y O N S == protons, protonsbar, neutrons, and neutronsbars | |
f87cfe57 | 357 | Double_t AliGenPHOSlib::PtBaryon( Double_t *px, Double_t *) |
358 | { | |
886b6f73 | 359 | // baryons |
360 | // pt-distribution | |
361 | //____________________________________________________________ | |
f87cfe57 | 362 | |
886b6f73 | 363 | return PtScal(*px,7); // 7==> Baryon in the PtScal function |
364 | } | |
365 | ||
886b6f73 | 366 | Double_t AliGenPHOSlib::YBaryon( Double_t *py, Double_t *) |
367 | { | |
f87cfe57 | 368 | // y-distribution |
369 | //____________________________________________________________ | |
370 | ||
371 | const Double_t ka = 1000.; | |
372 | const Double_t kdy = 4.; | |
886b6f73 | 373 | |
374 | ||
375 | Double_t y=TMath::Abs(*py); | |
376 | // | |
f87cfe57 | 377 | Double_t ex = y*y/(2*kdy*kdy); |
378 | return ka*TMath::Exp(-ex); | |
886b6f73 | 379 | } |
380 | ||
886b6f73 | 381 | Int_t AliGenPHOSlib::IpBaryon() |
382 | { | |
f87cfe57 | 383 | // particle composition |
384 | // | |
385 | ||
886b6f73 | 386 | Float_t random[1],random2[1]; |
387 | gMC->Rndm(random,1); | |
388 | gMC->Rndm(random2,1); | |
389 | if (random2[0] < 0.5) | |
390 | { | |
391 | if (random[0] < 0.5) { | |
392 | return 2212; // p | |
393 | } else { | |
394 | return -2212; // pbar | |
395 | } | |
396 | } | |
397 | else | |
398 | { | |
399 | if (random[0] < 0.5) { | |
400 | return 2112; // n | |
401 | } else { | |
402 | return -2112; // n bar | |
403 | } | |
404 | } | |
405 | } | |
406 | // End Baryons | |
407 | //=================================================================== | |
408 | ||
409 | ||
410 | typedef Double_t (*GenFunc) (Double_t*, Double_t*); | |
b22ee262 | 411 | GenFunc AliGenPHOSlib::GetPt(Param_t param, const char* tname) |
886b6f73 | 412 | { |
f87cfe57 | 413 | // Return pinter to pT parameterisation |
886b6f73 | 414 | GenFunc func; |
415 | ||
416 | switch (param) | |
417 | { | |
418 | case Pion: | |
419 | func=PtPion; | |
420 | break; | |
421 | case Kaon: | |
422 | func=PtKaon; | |
423 | break; | |
424 | case Eta: | |
425 | func=PtEta; | |
426 | break; | |
427 | case Omega: | |
428 | func=PtOmega; | |
429 | break; | |
430 | case Etaprime: | |
431 | func=PtEtaprime; | |
432 | break; | |
433 | case Baryon: | |
434 | func=PtBaryon; | |
435 | break; | |
436 | default: | |
437 | func=0; | |
438 | printf("<AliGenPHOSlib::GetPt> unknown parametrisationn"); | |
439 | } | |
440 | return func; | |
441 | } | |
442 | ||
b22ee262 | 443 | GenFunc AliGenPHOSlib::GetY(Param_t param, const char* tname) |
886b6f73 | 444 | { |
f87cfe57 | 445 | // Return pointer to Y parameterisation |
886b6f73 | 446 | GenFunc func; |
447 | switch (param) | |
448 | { | |
449 | case Pion: | |
450 | func=YPion; | |
451 | break; | |
452 | case Kaon: | |
453 | func=YKaon; | |
454 | break; | |
455 | case Eta: | |
456 | func=YEta; | |
457 | break; | |
458 | case Omega: | |
459 | func=YOmega; | |
460 | break; | |
461 | case Etaprime: | |
462 | func=YEtaprime; | |
463 | break; | |
464 | case Phi: | |
465 | func=YPhi; | |
466 | break; | |
467 | case Baryon: | |
468 | func=YBaryon; | |
469 | break; | |
470 | default: | |
471 | func=0; | |
472 | printf("<AliGenPHOSlib::GetY> unknown parametrisationn"); | |
473 | } | |
474 | return func; | |
475 | } | |
476 | typedef Int_t (*GenFuncIp) (); | |
b22ee262 | 477 | GenFuncIp AliGenPHOSlib::GetIp(Param_t param, const char* tname) |
886b6f73 | 478 | { |
f87cfe57 | 479 | // Return pointer to particle composition |
886b6f73 | 480 | GenFuncIp func; |
481 | switch (param) | |
482 | { | |
483 | case Pion: | |
484 | ||
485 | func=IpPion; | |
486 | break; | |
487 | case Kaon: | |
488 | func=IpKaon; | |
489 | break; | |
490 | case Eta: | |
491 | func=IpEta; | |
492 | break; | |
493 | case Omega: | |
494 | func=IpOmega; | |
495 | break; | |
496 | case Etaprime: | |
497 | func=IpEtaprime; | |
498 | break; | |
499 | case Phi: | |
500 | func=IpPhi; | |
501 | break; | |
502 | case Baryon: | |
503 | func=IpBaryon; | |
504 | break; | |
505 | default: | |
506 | func=0; | |
507 | printf("<AliGenPHOSlib::GetIp> unknown parametrisationn"); | |
508 | } | |
509 | return func; | |
510 | } | |
511 |