4c039060 |
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 | $Log$ |
18 | */ |
19 | |
fe4da5cc |
20 | #include "AliGenMUONlib.h" |
21 | #include "AliRun.h" |
22 | ClassImp(AliGenMUONlib) |
23 | // |
24 | // Pions |
25 | Double_t AliGenMUONlib::PtPion(Double_t *px, Double_t *) |
26 | { |
27 | // |
28 | // PT-PARAMETERIZATION CDF, PRL 61(88) 1819 |
29 | // POWER LAW FOR PT > 500 MEV |
30 | // MT SCALING BELOW (T=160 MEV) |
31 | // |
32 | const Double_t p0 = 1.3; |
33 | const Double_t xn = 8.28; |
34 | const Double_t xlim=0.5; |
35 | const Double_t t=0.160; |
36 | const Double_t xmpi=0.139; |
37 | const Double_t b=1.; |
38 | Double_t y, y1, xmpi2, ynorm, a; |
39 | Double_t x=*px; |
40 | // |
41 | y1=TMath::Power(p0/(p0+xlim),xn); |
42 | xmpi2=xmpi*xmpi; |
43 | ynorm=b*(TMath::Exp(-sqrt(xlim*xlim+xmpi2)/t)); |
44 | a=ynorm/y1; |
45 | if (x > xlim) |
46 | y=a*TMath::Power(p0/(p0+x),xn); |
47 | else |
48 | y=b*TMath::Exp(-sqrt(x*x+xmpi2)/t); |
49 | return y*x; |
50 | } |
753690b0 |
51 | // |
52 | // y-distribution |
53 | // |
54 | Double_t AliGenMUONlib::YPion( Double_t *py, Double_t *) |
55 | { |
56 | const Double_t a = 7000.; |
57 | const Double_t dy = 4.; |
58 | |
59 | Double_t y=TMath::Abs(*py); |
60 | // |
61 | Double_t ex = y*y/(2*dy*dy); |
62 | return a*TMath::Exp(-ex); |
63 | } |
64 | // particle composition |
65 | // |
66 | Int_t AliGenMUONlib::IpPion() |
67 | { |
753690b0 |
68 | Float_t random[1]; |
cfce8870 |
69 | gMC->Rndm(random,1); |
753690b0 |
70 | if (random[0] < 0.5) { |
71 | return 211; |
72 | } else { |
73 | return -211; |
74 | } |
75 | } |
fe4da5cc |
76 | |
77 | //____________________________________________________________ |
78 | // |
79 | // Mt-scaling |
80 | |
81 | Double_t AliGenMUONlib::PtScal(Double_t pt, Int_t np) |
82 | { |
83 | // SCALING EN MASSE PAR RAPPORT A PTPI |
84 | // MASS PI,K,ETA,RHO,OMEGA,ETA',PHI |
85 | const Double_t hm[10] = {.13957,.493,.5488,.769,.7826,.958,1.02,0,0,0}; |
86 | // VALUE MESON/PI AT 5 GEV |
87 | const Double_t fmax[10]={1.,0.3,0.55,1.0,1.0,1.0,1.0,0,0,0}; |
88 | np--; |
89 | Double_t f5=TMath::Power(((sqrt(100.018215)+2.)/(sqrt(100.+hm[np]*hm[np])+2.0)),12.3); |
90 | Double_t fmax2=f5/fmax[np]; |
91 | // PIONS |
92 | Double_t ptpion=100.*PtPion(&pt, (Double_t*) 0); |
93 | Double_t fmtscal=TMath::Power(((sqrt(pt*pt+0.018215)+2.)/ |
94 | (sqrt(pt*pt+hm[np]*hm[np])+2.0)),12.3)/ fmax2; |
95 | return fmtscal*ptpion; |
96 | } |
97 | // |
753690b0 |
98 | // kaon |
99 | // |
100 | // pt-distribution |
101 | //____________________________________________________________ |
102 | Double_t AliGenMUONlib::PtKaon( Double_t *px, Double_t *) |
103 | { |
104 | return PtScal(*px,2); |
105 | } |
106 | |
107 | // y-distribution |
fe4da5cc |
108 | //____________________________________________________________ |
753690b0 |
109 | Double_t AliGenMUONlib::YKaon( Double_t *py, Double_t *) |
fe4da5cc |
110 | { |
753690b0 |
111 | const Double_t a = 1000.; |
112 | const Double_t dy = 4.; |
113 | |
114 | |
fe4da5cc |
115 | Double_t y=TMath::Abs(*py); |
116 | // |
753690b0 |
117 | Double_t ex = y*y/(2*dy*dy); |
118 | return a*TMath::Exp(-ex); |
119 | } |
120 | |
121 | // particle composition |
122 | // |
123 | Int_t AliGenMUONlib::IpKaon() |
124 | { |
753690b0 |
125 | Float_t random[1]; |
cfce8870 |
126 | gMC->Rndm(random,1); |
753690b0 |
127 | if (random[0] < 0.5) { |
128 | return 321; |
129 | } else { |
130 | return -321; |
131 | } |
fe4da5cc |
132 | } |
753690b0 |
133 | |
fe4da5cc |
134 | // J/Psi |
135 | // |
136 | // |
137 | // pt-distribution |
138 | //____________________________________________________________ |
139 | Double_t AliGenMUONlib::PtJpsi( Double_t *px, Double_t *) |
140 | { |
141 | const Double_t pt0 = 4.; |
142 | const Double_t xn = 3.6; |
143 | Double_t x=*px; |
144 | // |
145 | Double_t pass1 = 1.+(x/pt0)*(x/pt0); |
146 | return x/TMath::Power(pass1,xn); |
147 | } |
148 | // |
149 | // y-distribution |
150 | //____________________________________________________________ |
151 | Double_t AliGenMUONlib::YJpsi(Double_t *py, Double_t *) |
152 | { |
153 | const Double_t y0 = 4.; |
154 | const Double_t b=1.; |
155 | Double_t yj; |
156 | Double_t y=TMath::Abs(*py); |
157 | // |
158 | if (y < y0) |
159 | yj=b; |
160 | else |
161 | yj=b*TMath::Exp(-(y-y0)*(y-y0)/2); |
162 | return yj; |
163 | } |
164 | // particle composition |
165 | // |
166 | Int_t AliGenMUONlib::IpJpsi() |
167 | { |
168 | return 443; |
169 | } |
170 | |
171 | // Upsilon |
172 | // |
173 | // |
174 | // pt-distribution |
175 | //____________________________________________________________ |
176 | Double_t AliGenMUONlib::PtUpsilon( Double_t *px, Double_t * ) |
177 | { |
178 | const Double_t pt0 = 5.3; |
179 | const Double_t xn = 2.5; |
180 | Double_t x=*px; |
181 | // |
182 | Double_t pass1 = 1.+(x/pt0)*(x/pt0); |
183 | return x/TMath::Power(pass1,xn); |
184 | } |
185 | // |
186 | // y-distribution |
187 | // |
188 | //____________________________________________________________ |
189 | Double_t AliGenMUONlib::YUpsilon(Double_t *py, Double_t *) |
190 | { |
191 | const Double_t y0 = 3.; |
192 | const Double_t b=1.; |
193 | Double_t yu; |
194 | Double_t y=TMath::Abs(*py); |
195 | // |
196 | if (y < y0) |
197 | yu=b; |
198 | else |
199 | yu=b*TMath::Exp(-(y-y0)*(y-y0)/2); |
200 | return yu; |
201 | } |
202 | // particle composition |
203 | // |
204 | Int_t AliGenMUONlib::IpUpsilon() |
205 | { |
206 | return 553; |
207 | } |
208 | |
209 | // |
210 | // Phi |
211 | // |
212 | // |
213 | // pt-distribution (by scaling of pion distribution) |
214 | //____________________________________________________________ |
215 | Double_t AliGenMUONlib::PtPhi( Double_t *px, Double_t *) |
216 | { |
217 | return PtScal(*px,7); |
218 | } |
219 | // y-distribution |
220 | Double_t AliGenMUONlib::YPhi( Double_t *px, Double_t *) |
221 | { |
ccdc344b |
222 | Double_t *dummy=0; |
fe4da5cc |
223 | return YJpsi(px,dummy); |
224 | } |
225 | // particle composition |
226 | // |
227 | Int_t AliGenMUONlib::IpPhi() |
228 | { |
229 | return 41; |
230 | } |
231 | |
232 | // |
233 | // Charm |
234 | // |
235 | // |
236 | // pt-distribution |
237 | //____________________________________________________________ |
238 | Double_t AliGenMUONlib::PtCharm( Double_t *px, Double_t *) |
239 | { |
240 | const Double_t pt0 = 4.08; |
241 | const Double_t xn = 9.40; |
242 | Double_t x=*px; |
243 | // |
244 | Double_t pass1 = 1.+(x/pt0)*(x/pt0); |
245 | return x/TMath::Power(pass1,xn); |
246 | } |
247 | // y-distribution |
248 | Double_t AliGenMUONlib::YCharm( Double_t *px, Double_t *) |
249 | { |
ccdc344b |
250 | Double_t *dummy=0; |
fe4da5cc |
251 | return YJpsi(px,dummy); |
252 | } |
253 | |
254 | Int_t AliGenMUONlib::IpCharm() |
255 | { |
fe4da5cc |
256 | Float_t random[2]; |
257 | Int_t ip; |
258 | // 411,421,431,4122 |
cfce8870 |
259 | gMC->Rndm(random,2); |
fe4da5cc |
260 | if (random[0] < 0.5) { |
261 | ip=411; |
262 | } else if (random[0] < 0.75) { |
263 | ip=421; |
264 | } else if (random[0] < 0.90) { |
265 | ip=431; |
266 | } else { |
267 | ip=4122; |
268 | } |
269 | if (random[1] < 0.5) {ip=-ip;} |
270 | |
271 | return ip; |
272 | } |
273 | |
274 | |
275 | // |
276 | // Beauty |
277 | // |
278 | // |
279 | // pt-distribution |
280 | //____________________________________________________________ |
281 | Double_t AliGenMUONlib::PtBeauty( Double_t *px, Double_t *) |
282 | { |
283 | const Double_t pt0 = 4.; |
284 | const Double_t xn = 3.6; |
285 | Double_t x=*px; |
286 | // |
287 | Double_t pass1 = 1.+(x/pt0)*(x/pt0); |
288 | return x/TMath::Power(pass1,xn); |
289 | } |
290 | // y-distribution |
291 | Double_t AliGenMUONlib::YBeauty( Double_t *px, Double_t *) |
292 | { |
ccdc344b |
293 | Double_t *dummy=0; |
fe4da5cc |
294 | return YJpsi(px,dummy); |
295 | } |
296 | |
297 | Int_t AliGenMUONlib::IpBeauty() |
298 | { |
fe4da5cc |
299 | Float_t random[2]; |
300 | Int_t ip; |
cfce8870 |
301 | gMC->Rndm(random,2); |
fe4da5cc |
302 | if (random[0] < 0.5) { |
303 | ip=511; |
304 | } else if (random[0] < 0.75) { |
305 | ip=521; |
306 | } else if (random[0] < 0.90) { |
307 | ip=531; |
308 | } else { |
309 | ip=5122; |
310 | } |
311 | if (random[1] < 0.5) {ip=-ip;} |
312 | |
313 | return ip; |
314 | } |
315 | |
316 | typedef Double_t (*GenFunc) (Double_t*, Double_t*); |
753690b0 |
317 | GenFunc AliGenMUONlib::GetPt(Param_t param) |
fe4da5cc |
318 | { |
319 | GenFunc func; |
753690b0 |
320 | switch (param) |
fe4da5cc |
321 | { |
753690b0 |
322 | case phi_p: |
fe4da5cc |
323 | func=PtPhi; |
324 | break; |
753690b0 |
325 | case jpsi_p: |
fe4da5cc |
326 | func=PtJpsi; |
327 | break; |
753690b0 |
328 | case upsilon_p: |
fe4da5cc |
329 | func=PtUpsilon; |
330 | break; |
753690b0 |
331 | case charm_p: |
fe4da5cc |
332 | func=PtCharm; |
333 | break; |
753690b0 |
334 | case beauty_p: |
fe4da5cc |
335 | func=PtBeauty; |
336 | break; |
753690b0 |
337 | case pion_p: |
338 | func=PtPion; |
339 | break; |
340 | case kaon_p: |
341 | func=PtKaon; |
342 | break; |
119b35c7 |
343 | default: |
344 | func=0; |
345 | printf("<AliGenMUONlib::GetPt> unknown parametrisation\n"); |
fe4da5cc |
346 | } |
347 | return func; |
348 | } |
349 | |
753690b0 |
350 | GenFunc AliGenMUONlib::GetY(Param_t param) |
fe4da5cc |
351 | { |
352 | GenFunc func; |
753690b0 |
353 | switch (param) |
fe4da5cc |
354 | { |
753690b0 |
355 | case phi_p: |
fe4da5cc |
356 | func=YPhi; |
357 | break; |
753690b0 |
358 | case jpsi_p: |
fe4da5cc |
359 | func=YJpsi; |
360 | break; |
753690b0 |
361 | case upsilon_p: |
fe4da5cc |
362 | func=YUpsilon; |
363 | break; |
753690b0 |
364 | case charm_p: |
fe4da5cc |
365 | func=YCharm; |
366 | break; |
753690b0 |
367 | case beauty_p: |
fe4da5cc |
368 | func=YBeauty; |
369 | break; |
753690b0 |
370 | case pion_p: |
371 | func=YPion; |
372 | break; |
373 | case kaon_p: |
374 | func=YKaon; |
375 | break; |
119b35c7 |
376 | default: |
377 | func=0; |
378 | printf("<AliGenMUONlib::GetY> unknown parametrisation\n"); |
fe4da5cc |
379 | } |
380 | return func; |
381 | } |
382 | typedef Int_t (*GenFuncIp) (); |
753690b0 |
383 | GenFuncIp AliGenMUONlib::GetIp(Param_t param) |
fe4da5cc |
384 | { |
385 | GenFuncIp func; |
753690b0 |
386 | switch (param) |
fe4da5cc |
387 | { |
753690b0 |
388 | case phi_p: |
fe4da5cc |
389 | func=IpPhi; |
390 | break; |
753690b0 |
391 | case jpsi_p: |
fe4da5cc |
392 | func=IpJpsi; |
393 | break; |
753690b0 |
394 | case upsilon_p: |
fe4da5cc |
395 | func=IpUpsilon; |
396 | break; |
753690b0 |
397 | case charm_p: |
fe4da5cc |
398 | func=IpCharm; |
399 | break; |
753690b0 |
400 | case beauty_p: |
fe4da5cc |
401 | func=IpBeauty; |
402 | break; |
753690b0 |
403 | case pion_p: |
404 | func=IpPion; |
405 | break; |
406 | case kaon_p: |
407 | func=IpKaon; |
408 | break; |
119b35c7 |
409 | default: |
410 | func=0; |
411 | printf("<AliGenMUONlib::GetIp> unknown parametrisation\n"); |
fe4da5cc |
412 | } |
413 | return func; |
414 | } |
415 | |
416 | |
753690b0 |
417 | |
418 | |