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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 | /* $Id$ */ | |
17 | ||
18 | /* History of cvs commits: | |
19 | * | |
20 | * $Log$ | |
21 | * Revision 1.30 2006/09/13 07:31:01 kharlov | |
22 | * Effective C++ corrections (T.Pocheptsov) | |
23 | * | |
24 | * Revision 1.29 2005/05/28 14:19:05 schutz | |
25 | * Compilation warnings fixed by T.P. | |
26 | * | |
27 | */ | |
28 | ||
29 | //_________________________________________________________________________ | |
30 | // Implementation of the PHOS manager class for fast simulations | |
31 | // Tracks particles until the reach a grossly designed PHOS module | |
32 | // Modify the particles property (momentum, energy, type) according to | |
33 | // the PHOS response function. The result is called a virtual reconstructed | |
34 | // particle. | |
35 | // | |
36 | //*-- Author: Yves Schutz (SUBATECH) | |
37 | ||
38 | // --- ROOT system --- | |
39 | ||
40 | #include <TGeometry.h> | |
41 | #include <TParticle.h> | |
42 | #include <TDatabasePDG.h> | |
43 | #include "TClonesArray.h" | |
44 | #include <TVirtualMC.h> | |
45 | ||
46 | // --- Standard library --- | |
47 | ||
48 | // --- AliRoot header files --- | |
49 | #include "AliPHOSFastRecParticle.h" | |
50 | #include "AliPHOSGeometry.h" | |
51 | #include "AliPHOSLoader.h" | |
52 | #include "AliPHOSvFast.h" | |
53 | #include "AliRun.h" | |
54 | ||
55 | ClassImp(AliPHOSvFast) | |
56 | ||
57 | AliPHOSvFast::AliPHOSvFast() : | |
58 | fBigBoxX(0.), | |
59 | fBigBoxY(0.), | |
60 | fBigBoxZ(0.), | |
61 | fFastRecParticles(0), | |
62 | fNRecParticles(0), | |
63 | fRan(0), | |
64 | fResPara1(0.), | |
65 | fResPara2(0.), | |
66 | fResPara3(0.), | |
67 | fPosParaA0(0.), | |
68 | fPosParaA1(0.), | |
69 | fPosParaB0(0.), | |
70 | fPosParaB1(0.), | |
71 | fPosParaB2(0.) | |
72 | { | |
73 | // default ctor : initialize data member | |
74 | } | |
75 | ||
76 | //____________________________________________________________________________ | |
77 | AliPHOSvFast::AliPHOSvFast(const char *name, const char *title): | |
78 | AliPHOS(name,title), | |
79 | fBigBoxX(0.), | |
80 | fBigBoxY(0.), | |
81 | fBigBoxZ(0.), | |
82 | fFastRecParticles(new AliPHOSFastRecParticle::FastRecParticlesList("AliPHOSFastRecParticle", 100)), | |
83 | fNRecParticles(0), | |
84 | fRan(0), | |
85 | fResPara1(0.030), // GeV | |
86 | fResPara2(0.00003), | |
87 | fResPara3(0.00001), | |
88 | fPosParaA0(2.87), // mm | |
89 | fPosParaA1(-0.0975), | |
90 | fPosParaB0(0.257), | |
91 | fPosParaB1(0.137), | |
92 | fPosParaB2(0.00619) | |
93 | { | |
94 | // ctor | |
95 | // create the Loader | |
96 | SetBigBox(0, GetGeometry()->GetOuterBoxSize(0) ) ; | |
97 | SetBigBox(1, GetGeometry()->GetOuterBoxSize(3) + GetGeometry()->GetCPVBoxSize(1) ) ; | |
98 | SetBigBox(2, GetGeometry()->GetOuterBoxSize(2) ); | |
99 | } | |
100 | ||
101 | //____________________________________________________________________________ | |
102 | AliPHOSvFast::~AliPHOSvFast() | |
103 | { | |
104 | // dtor | |
105 | ||
106 | fFastRecParticles->Delete() ; | |
107 | delete fFastRecParticles ; | |
108 | fFastRecParticles = 0 ; | |
109 | ||
110 | } | |
111 | ||
112 | //____________________________________________________________________________ | |
113 | void AliPHOSvFast::AddRecParticle(const AliPHOSFastRecParticle & rp) | |
114 | { | |
115 | // Add a virtually reconstructed particle to the list | |
116 | ||
117 | new( (*fFastRecParticles)[fNRecParticles] ) AliPHOSFastRecParticle(rp) ; | |
118 | fNRecParticles++ ; | |
119 | } | |
120 | ||
121 | //____________________________________________________________________________ | |
122 | void AliPHOSvFast::CreateGeometry() | |
123 | { | |
124 | // Create the geometry for GEANT | |
125 | ||
126 | AliPHOSvFast *phostmp = (AliPHOSvFast*)gAlice->GetModule("PHOS") ; | |
127 | ||
128 | if ( phostmp == NULL ) { | |
129 | ||
130 | fprintf(stderr, "PHOS detector not found!\n") ; | |
131 | return ; | |
132 | ||
133 | } | |
134 | ||
135 | // Get pointer to the array containing media indeces | |
136 | Int_t *idtmed = fIdtmed->GetArray() - 699 ; | |
137 | ||
138 | Float_t bigbox[3] ; | |
139 | bigbox[0] = GetBigBox(0) / 2.0 ; | |
140 | bigbox[1] = GetBigBox(1) / 2.0 ; | |
141 | bigbox[2] = GetBigBox(2) / 2.0 ; | |
142 | ||
143 | gMC->Gsvolu("PHOS", "BOX ", idtmed[798], bigbox, 3) ; | |
144 | ||
145 | // --- Position PHOS mdules in ALICE setup --- | |
146 | ||
147 | Int_t idrotm[99] ; | |
148 | Double_t const kRADDEG = 180.0 / TMath::Pi() ; | |
149 | ||
150 | for( Int_t i = 1; i <= GetGeometry()->GetNModules(); i++ ) { | |
151 | ||
152 | Float_t angle = GetGeometry()->GetPHOSAngle(i) ; | |
153 | AliMatrix(idrotm[i-1], 90.0, angle, 90.0, 90.0+angle, 0.0, 0.0) ; | |
154 | ||
155 | Float_t r = GetGeometry()->GetIPtoCrystalSurface() + GetBigBox(1) / 2.0 ; | |
156 | ||
157 | Float_t xP1 = r * TMath::Sin( angle / kRADDEG ) ; | |
158 | Float_t yP1 = -r * TMath::Cos( angle / kRADDEG ) ; | |
159 | gMC->Gspos("PHOS", i, "ALIC", xP1, yP1, 0.0, idrotm[i-1], "ONLY") ; | |
160 | ||
161 | } // for GetNModules | |
162 | ||
163 | } | |
164 | ||
165 | ||
166 | //____________________________________________________________________________ | |
167 | void AliPHOSvFast::Init(void) | |
168 | { | |
169 | // Prints out an information message | |
170 | ||
171 | Int_t i; | |
172 | ||
173 | printf("\n"); | |
174 | for(i=0;i<35;i++) printf("*"); | |
175 | printf(" FAST PHOS_INIT "); | |
176 | for(i=0;i<35;i++) printf("*"); | |
177 | printf("\n"); | |
178 | ||
179 | // Here the PHOS initialisation code (if any!) | |
180 | ||
181 | for(i=0;i<80;i++) printf("*"); | |
182 | printf("\n"); | |
183 | ||
184 | } | |
185 | ||
186 | //___________________________________________________________________________ | |
187 | Float_t AliPHOSvFast::GetBigBox(Int_t index) const | |
188 | { | |
189 | // Get the X, Y or Z dimension of the box describing a PHOS module | |
190 | ||
191 | Float_t rv = 0 ; | |
192 | ||
193 | switch (index) { | |
194 | case 0: | |
195 | rv = fBigBoxX ; | |
196 | break ; | |
197 | case 1: | |
198 | rv = fBigBoxY ; | |
199 | break ; | |
200 | case 2: | |
201 | rv = fBigBoxZ ; | |
202 | break ; | |
203 | } | |
204 | return rv ; | |
205 | } | |
206 | //___________________________________________________________________________ | |
207 | ||
208 | void AliPHOSvFast::MakeBranch(Option_t* opt) | |
209 | { | |
210 | // Create new branch in the current reconstructed Root Tree | |
211 | AliDetector::MakeBranch(opt); | |
212 | const char *cd = strstr(opt,"R"); | |
213 | ||
214 | if (fFastRecParticles && fLoader->TreeR() && cd) { | |
215 | MakeBranchInTree(fLoader->TreeR(), GetName(), &fFastRecParticles, fBufferSize, 0); | |
216 | } | |
217 | } | |
218 | //____________________________________________________________________________ | |
219 | ||
220 | Double_t AliPHOSvFast::MakeEnergy(Double_t energy) | |
221 | { | |
222 | // Smears the energy according to the energy dependent energy resolution. | |
223 | // A gaussian distribution is assumed | |
224 | ||
225 | Double_t sigma = SigmaE(energy) ; | |
226 | return fRan.Gaus(energy, sigma) ; | |
227 | } | |
228 | //____________________________________________________________________________ | |
229 | ||
230 | TVector3 AliPHOSvFast::MakePosition(Double_t energy, TVector3 pos, Double_t theta, Double_t phi) | |
231 | { | |
232 | // Smears the impact position according to the energy dependent position resolution | |
233 | // A gaussian position distribution is assumed | |
234 | ||
235 | TVector3 newpos ; | |
236 | Double_t sigma = SigmaP( energy, theta*180./TMath::Pi() ) ; | |
237 | Double_t x = fRan.Gaus( pos.X(), sigma ) ; | |
238 | sigma = SigmaP( energy, phi*180./TMath::Pi() ) ; | |
239 | Double_t z = fRan.Gaus( pos.Z(), sigma ) ; | |
240 | Double_t y = pos.Y() ; | |
241 | ||
242 | newpos.SetX(x) ; | |
243 | newpos.SetY(y) ; | |
244 | newpos.SetZ(z) ; | |
245 | ||
246 | return newpos ; | |
247 | } | |
248 | ||
249 | //____________________________________________________________________________ | |
250 | void AliPHOSvFast::MakeRecParticle(Int_t modid, TVector3 pos, AliPHOSFastRecParticle & rp) | |
251 | { | |
252 | // Modify the primary particle properties according | |
253 | // 1. the response function of PHOS | |
254 | // 2. the performance of the EMC+PPSD setup | |
255 | ||
256 | Int_t type = MakeType( rp ) ; | |
257 | rp.SetType(type) ; | |
258 | ||
259 | ||
260 | // get the detected energy | |
261 | ||
262 | TLorentzVector momentum ; | |
263 | rp.Momentum(momentum) ; | |
264 | Double_t kineticenergy = TMath::Sqrt( TMath::Power(momentum.E(), 2) - TMath::Power(rp.GetMass(), 2) ) ; | |
265 | Double_t modifiedkineticenergy = MakeEnergy(kineticenergy ) ; | |
266 | Double_t modifiedenergy = TMath::Sqrt( TMath::Power(modifiedkineticenergy, 2) | |
267 | + TMath::Power( rp.GetMass(), 2) ) ; | |
268 | ||
269 | // get the angle of incidence | |
270 | ||
271 | Double_t incidencetheta = 90. * TMath::Pi() /180 - rp.Theta() ; | |
272 | Double_t incidencephi = ( 270 + GetGeometry()->GetPHOSAngle(modid) ) * TMath::Pi() / 180. - rp.Phi() ; | |
273 | ||
274 | // get the detected direction | |
275 | ||
276 | TVector3 modifiedposition = MakePosition(kineticenergy, pos, incidencetheta, incidencephi) ; | |
277 | modifiedposition *= modifiedkineticenergy / modifiedposition.Mag() ; | |
278 | ||
279 | // Set the modified 4-momentum of the reconstructed particle | |
280 | ||
281 | rp.SetMomentum(modifiedposition.X(), modifiedposition.Y(), modifiedposition.Z(), modifiedenergy) ; | |
282 | ||
283 | } | |
284 | ||
285 | //____________________________________________________________________________ | |
286 | Int_t AliPHOSvFast::MakeType(AliPHOSFastRecParticle & rp ) | |
287 | { | |
288 | // Generate a particle type using the performance of the EMC+PPSD setup | |
289 | ||
290 | Int_t rv = AliPHOSFastRecParticle::kUNDEFINED ; | |
291 | Int_t charge = (Int_t)rp.GetPDG()->Charge() ; | |
292 | Int_t test ; | |
293 | Float_t ran ; | |
294 | if ( charge != 0 && ( TMath::Abs(rp.GetPdgCode()) != 11 ) ) | |
295 | test = - 1 ; | |
296 | else | |
297 | test = rp.GetPdgCode() ; | |
298 | ||
299 | Fatal("MakeType", "SHOULD NOT BE USED until values of probabilities are properly set ") ; | |
300 | // NB: ALL VALUES SHOULD BE CHECKED !!!! | |
301 | switch (test) { | |
302 | ||
303 | case 22: // it's a photon // NB: ALL VALUES SHOLD BE CHECKED !!!! | |
304 | ran = fRan.Rndm() ; | |
305 | if( ran <= 0.9498 ) | |
306 | rv = AliPHOSFastRecParticle::kNEUTRALHAFAST ; | |
307 | else | |
308 | rv = AliPHOSFastRecParticle::kNEUTRALEMFAST ; | |
309 | break ; | |
310 | ||
311 | case 2112: // it's a neutron | |
312 | ran = fRan.Rndm() ; | |
313 | if ( ran <= 0.9998 ) | |
314 | rv = AliPHOSFastRecParticle::kNEUTRALHASLOW ; | |
315 | else | |
316 | rv = AliPHOSFastRecParticle::kNEUTRALEMSLOW ; | |
317 | break ; | |
318 | ||
319 | case -2112: // it's a anti-neutron | |
320 | ran = fRan.Rndm() ; | |
321 | if ( ran <= 0.9984 ) | |
322 | rv = AliPHOSFastRecParticle::kNEUTRALHASLOW ; | |
323 | else | |
324 | rv = AliPHOSFastRecParticle::kNEUTRALEMSLOW ; | |
325 | break ; | |
326 | ||
327 | case 11: // it's a electron | |
328 | ran = fRan.Rndm() ; | |
329 | if ( ran <= 0.9996 ) | |
330 | rv = AliPHOSFastRecParticle::kCHARGEDEMFAST ; | |
331 | else | |
332 | rv = AliPHOSFastRecParticle::kCHARGEDHAFAST ; | |
333 | break; | |
334 | ||
335 | case -11: // it's a positon | |
336 | ran = fRan.Rndm() ; | |
337 | if ( ran <= 0.9996 ) | |
338 | rv = AliPHOSFastRecParticle::kCHARGEDEMFAST ; | |
339 | else | |
340 | rv = AliPHOSFastRecParticle::kCHARGEDHAFAST ; | |
341 | break; | |
342 | ||
343 | case -1: // it's a charged | |
344 | ran = fRan.Rndm() ; | |
345 | if ( ran <= 0.9996 ) | |
346 | rv = AliPHOSFastRecParticle::kCHARGEDHAFAST ; | |
347 | else | |
348 | rv = AliPHOSFastRecParticle::kNEUTRALHAFAST ; | |
349 | ||
350 | break ; | |
351 | } | |
352 | ||
353 | ||
354 | return rv ; | |
355 | } | |
356 | ||
357 | //___________________________________________________________________________ | |
358 | void AliPHOSvFast::ResetPoints() | |
359 | { | |
360 | // This overloads the method in AliDetector | |
361 | ||
362 | ResetFastRecParticles() ; | |
363 | } | |
364 | ||
365 | //___________________________________________________________________________ | |
366 | void AliPHOSvFast::ResetFastRecParticles() | |
367 | { | |
368 | // Resets the list of virtual reconstructed particles | |
369 | ||
370 | if (fFastRecParticles) | |
371 | fFastRecParticles->Clear() ; | |
372 | fNRecParticles = 0 ; | |
373 | } | |
374 | ||
375 | //___________________________________________________________________________ | |
376 | void AliPHOSvFast::SetBigBox(Int_t index, Float_t value) | |
377 | { | |
378 | // Set the size of the Box describing a PHOS module | |
379 | ||
380 | switch (index) { | |
381 | case 0: | |
382 | fBigBoxX = value ; | |
383 | break ; | |
384 | case 1: | |
385 | fBigBoxY = value ; | |
386 | break ; | |
387 | case 2: | |
388 | fBigBoxZ = value ; | |
389 | break ; | |
390 | } | |
391 | ||
392 | } | |
393 | ||
394 | //____________________________________________________________________________ | |
395 | Double_t AliPHOSvFast::SigmaE(Double_t energy) | |
396 | { | |
397 | // Calculates the energy dependent energy resolution | |
398 | ||
399 | Double_t rv = -1 ; | |
400 | ||
401 | rv = TMath::Sqrt( TMath::Power(fResPara1/energy, 2) | |
402 | + TMath::Power(fResPara2/TMath::Sqrt(energy), 2) | |
403 | + TMath::Power(fResPara3, 2) ) ; | |
404 | ||
405 | return rv * energy ; | |
406 | } | |
407 | ||
408 | //____________________________________________________________________________ | |
409 | Double_t AliPHOSvFast::SigmaP(Double_t energy, Double_t incidence) | |
410 | { | |
411 | // Calculates the energy dependent position resolution | |
412 | ||
413 | Double_t paraA = fPosParaA0 + fPosParaA1 * incidence ; | |
414 | Double_t paraB = fPosParaB0 + fPosParaB1 * incidence + fPosParaB2 * incidence * incidence ; | |
415 | ||
416 | return ( paraA / TMath::Sqrt(energy) + paraB ) * 0.1 ; // in cm | |
417 | } | |
418 | ||
419 | //____________________________________________________________________________ | |
420 | void AliPHOSvFast::StepManager(void) | |
421 | { | |
422 | // Only verifies if the particle reaches PHOS and stops the tracking | |
423 | ||
424 | TLorentzVector lv ; | |
425 | gMC->TrackPosition(lv) ; | |
426 | TVector3 pos = lv.Vect() ; | |
427 | Int_t modid ; | |
428 | gMC->CurrentVolID(modid); | |
429 | ||
430 | Float_t energy = gMC->Etot() ; //Total energy of current track | |
431 | ||
432 | //Calculating mass of current particle | |
433 | TDatabasePDG * pdg = TDatabasePDG::Instance() ; | |
434 | TParticlePDG * partPDG = pdg->GetParticle(gMC->TrackPid()) ; | |
435 | Float_t mass = partPDG->Mass() ; | |
436 | ||
437 | if(energy > mass){ | |
438 | pos.SetMag(TMath::Sqrt(energy*energy-mass*mass)) ; | |
439 | TLorentzVector pTrack(pos, energy) ; | |
440 | ||
441 | TParticle * part = new TParticle(gMC->TrackPid(), 0,-1,-1,-1,-1, pTrack, lv) ; | |
442 | ||
443 | AliPHOSFastRecParticle rp(*part) ; | |
444 | ||
445 | // Adds the response of PHOS to the particle | |
446 | MakeRecParticle(modid, pos, rp) ; | |
447 | ||
448 | // add the `track' particle to the FastRecParticles list | |
449 | ||
450 | AddRecParticle(rp) ; | |
451 | ||
452 | part->Delete() ; | |
453 | } | |
454 | // stop the track as soon PHOS is reached | |
455 | ||
456 | gMC->StopTrack() ; | |
457 | ||
458 | } | |
459 |