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5f20d3fb | 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 | //_________________________________________________________________________ | |
19 | // Implementation of the PHOS manager class for fast simulations | |
20 | // Tracks particles until the reach a grossly designed PHOS module | |
21 | // Modify the particles property (momentum, energy, type) according to | |
22 | // the PHOS response function. The result is called a virtual reconstructed | |
23 | // particle. | |
24 | // | |
25 | //*-- Author: Yves Schutz (SUBATECH) | |
26 | ||
27 | // --- ROOT system --- | |
28 | ||
29 | #include "TBRIK.h" | |
30 | #include "TNode.h" | |
31 | #include "TParticle.h" | |
94de3818 | 32 | #include "TTree.h" |
33 | #include "TGeometry.h" | |
5f20d3fb | 34 | |
35 | // --- Standard library --- | |
36 | ||
37 | #include <stdio.h> | |
38 | ||
39 | // --- AliRoot header files --- | |
40 | ||
41 | #include "AliPHOSv4.h" | |
42 | #include "AliRun.h" | |
43 | #include "AliConst.h" | |
94de3818 | 44 | #include "AliMC.h" |
5f20d3fb | 45 | |
46 | ClassImp(AliPHOSv4) | |
47 | ||
5f20d3fb | 48 | //____________________________________________________________________________ |
49 | AliPHOSv4::AliPHOSv4(const char *name, const char *title): | |
50 | AliPHOS(name,title) | |
51 | { | |
52 | // ctor | |
53 | ||
54 | // gets an instance of the geometry parameters class | |
5cbba5aa | 55 | if (strcmp(GetTitle(),"") != 0 ) |
56 | fGeom = AliPHOSGeometry::GetInstance(GetTitle(), "") ; | |
e04976bd | 57 | |
aafe457d | 58 | |
59 | SetBigBox(0, fGeom->GetOuterBoxSize(0) ) ; | |
9a00a811 | 60 | SetBigBox(1, fGeom->GetOuterBoxSize(1) + fGeom->GetCPVBoxSize(1) ) ; |
aafe457d | 61 | SetBigBox(2, fGeom->GetOuterBoxSize(0) ); |
62 | ||
63 | fNRecParticles = 0 ; | |
64 | fFastRecParticles = new AliPHOSFastRecParticle::FastRecParticlesList("AliPHOSFastRecParticle", 100) ; | |
5cbba5aa | 65 | |
aafe457d | 66 | fResPara1 = 0.030 ; // GeV |
67 | fResPara2 = 0.00003 ; | |
68 | fResPara3 = 0.00001 ; | |
69 | ||
70 | fPosParaA0 = 2.87 ; // mm | |
71 | fPosParaA1 = -0.0975 ; | |
72 | fPosParaB0 = 0.257 ; | |
73 | fPosParaB1 = 0.137 ; | |
74 | fPosParaB2 = 0.00619 ; | |
5f20d3fb | 75 | } |
76 | ||
77 | //____________________________________________________________________________ | |
78 | AliPHOSv4::~AliPHOSv4() | |
79 | { | |
80 | // dtor | |
81 | ||
82 | fFastRecParticles->Delete() ; | |
83 | delete fFastRecParticles ; | |
84 | fFastRecParticles = 0 ; | |
85 | ||
86 | } | |
87 | ||
88 | //____________________________________________________________________________ | |
89 | void AliPHOSv4::AddRecParticle(const AliPHOSFastRecParticle & rp) | |
90 | { | |
91 | // Add a virtually reconstructed particle to the list | |
92 | ||
93 | new( (*fFastRecParticles)[fNRecParticles] ) AliPHOSFastRecParticle(rp) ; | |
94 | fNRecParticles++ ; | |
95 | } | |
96 | ||
97 | //____________________________________________________________________________ | |
98 | void AliPHOSv4::BuildGeometry() | |
99 | { | |
100 | // Build the PHOS geometry for the ROOT display | |
101 | //BEGIN_HTML | |
102 | /* | |
103 | <H2> | |
104 | PHOS FAST in ALICE displayed by root | |
105 | </H2> | |
106 | <H4> All Views </H4> | |
107 | <P> | |
108 | <CENTER> | |
109 | <IMG Align=BOTTOM ALT="Fast All Views" SRC="../images/AliPHOSv4AllViews.gif"> | |
110 | </CENTER></P> | |
111 | <H4> Front View </H4> | |
112 | <P> | |
113 | <CENTER> | |
114 | <IMG Align=BOTTOM ALT="Fast Front View" SRC="../images/AliPHOSv4FrontView.gif"> | |
115 | </CENTER></P> | |
116 | */ | |
117 | //END_HTML | |
118 | ||
119 | const Int_t kColorPHOS = kRed ; | |
120 | ||
121 | Double_t const kRADDEG = 180.0 / kPI ; | |
122 | ||
123 | new TBRIK( "BigBox", "PHOS box", "void", GetBigBox(0)/2, | |
124 | GetBigBox(1)/2, | |
125 | GetBigBox(2)/2 ); | |
126 | ||
127 | // position PHOS into ALICE | |
128 | ||
129 | Float_t r = fGeom->GetIPtoCrystalSurface() + GetBigBox(1) / 2.0 ; | |
130 | Int_t number = 988 ; | |
131 | Float_t pphi = TMath::ATan( GetBigBox(0) / ( 2.0 * fGeom->GetIPtoCrystalSurface() ) ) ; | |
132 | pphi *= kRADDEG ; | |
133 | TNode * top = gAlice->GetGeometry()->GetNode("alice") ; | |
134 | ||
135 | char * nodename = new char[20] ; | |
136 | char * rotname = new char[20] ; | |
137 | ||
138 | for( Int_t i = 1; i <= fGeom->GetNModules(); i++ ) { | |
139 | Float_t angle = pphi * 2 * ( i - fGeom->GetNModules() / 2.0 - 0.5 ) ; | |
140 | sprintf(rotname, "%s%d", "rot", number++) ; | |
141 | new TRotMatrix(rotname, rotname, 90, angle, 90, 90 + angle, 0, 0); | |
142 | top->cd(); | |
143 | sprintf(nodename,"%s%d", "Module", i) ; | |
144 | Float_t x = r * TMath::Sin( angle / kRADDEG ) ; | |
145 | Float_t y = -r * TMath::Cos( angle / kRADDEG ) ; | |
146 | TNode * bigboxnode = new TNode(nodename, nodename, "BigBox", x, y, 0, rotname ) ; | |
147 | bigboxnode->SetLineColor(kColorPHOS) ; | |
148 | fNodes->Add(bigboxnode) ; | |
149 | } | |
150 | delete[] nodename ; | |
151 | delete[] rotname ; | |
152 | } | |
153 | ||
154 | //____________________________________________________________________________ | |
155 | void AliPHOSv4::CreateGeometry() | |
156 | { | |
157 | // Create the geometry for GEANT | |
158 | ||
159 | AliPHOSv4 *phostmp = (AliPHOSv4*)gAlice->GetModule("PHOS") ; | |
160 | ||
161 | if ( phostmp == NULL ) { | |
162 | ||
163 | fprintf(stderr, "PHOS detector not found!\n") ; | |
164 | return ; | |
165 | ||
166 | } | |
167 | ||
168 | // Get pointer to the array containing media indeces | |
169 | Int_t *idtmed = fIdtmed->GetArray() - 699 ; | |
170 | ||
171 | Float_t bigbox[3] ; | |
172 | bigbox[0] = GetBigBox(0) / 2.0 ; | |
173 | bigbox[1] = GetBigBox(1) / 2.0 ; | |
174 | bigbox[2] = GetBigBox(2) / 2.0 ; | |
175 | ||
176 | gMC->Gsvolu("PHOS", "BOX ", idtmed[798], bigbox, 3) ; | |
177 | ||
178 | // --- Position PHOS mdules in ALICE setup --- | |
179 | ||
180 | Int_t idrotm[99] ; | |
181 | Double_t const kRADDEG = 180.0 / kPI ; | |
182 | ||
183 | for( Int_t i = 1; i <= fGeom->GetNModules(); i++ ) { | |
184 | ||
185 | Float_t angle = fGeom->GetPHOSAngle(i) ; | |
186 | AliMatrix(idrotm[i-1], 90.0, angle, 90.0, 90.0+angle, 0.0, 0.0) ; | |
187 | ||
188 | Float_t r = fGeom->GetIPtoCrystalSurface() + GetBigBox(1) / 2.0 ; | |
189 | ||
190 | Float_t xP1 = r * TMath::Sin( angle / kRADDEG ) ; | |
191 | Float_t yP1 = -r * TMath::Cos( angle / kRADDEG ) ; | |
192 | gMC->Gspos("PHOS", i, "ALIC", xP1, yP1, 0.0, idrotm[i-1], "ONLY") ; | |
193 | ||
194 | } // for GetNModules | |
195 | ||
196 | } | |
197 | ||
198 | ||
199 | //____________________________________________________________________________ | |
200 | void AliPHOSv4::Init(void) | |
201 | { | |
202 | // Prints out an information message | |
203 | ||
204 | Int_t i; | |
205 | ||
206 | printf("\n"); | |
207 | for(i=0;i<35;i++) printf("*"); | |
208 | printf(" FAST PHOS_INIT "); | |
209 | for(i=0;i<35;i++) printf("*"); | |
210 | printf("\n"); | |
211 | ||
212 | // Here the PHOS initialisation code (if any!) | |
213 | ||
214 | for(i=0;i<80;i++) printf("*"); | |
215 | printf("\n"); | |
216 | ||
217 | } | |
218 | ||
219 | //___________________________________________________________________________ | |
220 | Float_t AliPHOSv4::GetBigBox(Int_t index) | |
221 | { | |
222 | // Get the X, Y or Z dimension of the box describing a PHOS module | |
223 | ||
224 | Float_t rv = 0 ; | |
225 | ||
226 | switch (index) { | |
227 | case 0: | |
228 | rv = fBigBoxX ; | |
229 | break ; | |
230 | case 1: | |
231 | rv = fBigBoxY ; | |
232 | break ; | |
233 | case 2: | |
234 | rv = fBigBoxZ ; | |
235 | break ; | |
236 | } | |
237 | return rv ; | |
238 | } | |
239 | ||
240 | //___________________________________________________________________________ | |
241 | void AliPHOSv4::MakeBranch(Option_t* opt) | |
242 | { | |
243 | // Create new branch in the current reconstructed Root Tree | |
244 | ||
245 | AliDetector::MakeBranch(opt) ; | |
246 | ||
247 | char branchname[10]; | |
248 | sprintf(branchname,"%s",GetName()); | |
249 | char *cd = strstr(opt,"R"); | |
250 | ||
251 | if (fFastRecParticles && gAlice->TreeR() && cd) { | |
252 | gAlice->TreeR()->Branch(branchname, &fFastRecParticles, fBufferSize); | |
253 | } | |
254 | } | |
255 | ||
256 | //____________________________________________________________________________ | |
257 | Double_t AliPHOSv4::MakeEnergy(const Double_t energy) | |
258 | { | |
259 | // Smears the energy according to the energy dependent energy resolution. | |
260 | // A gaussian distribution is assumed | |
261 | ||
262 | Double_t sigma = SigmaE(energy) ; | |
263 | return fRan.Gaus(energy, sigma) ; | |
264 | } | |
265 | ||
266 | //____________________________________________________________________________ | |
267 | TVector3 AliPHOSv4::MakePosition(const Double_t energy, const TVector3 pos, const Double_t theta, const Double_t phi) | |
268 | { | |
269 | // Smears the impact position according to the energy dependent position resolution | |
270 | // A gaussian position distribution is assumed | |
271 | ||
272 | TVector3 newpos ; | |
273 | Double_t sigma = SigmaP( energy, theta*180./TMath::Pi() ) ; | |
274 | Double_t x = fRan.Gaus( pos.X(), sigma ) ; | |
275 | sigma = SigmaP( energy, phi*180./TMath::Pi() ) ; | |
276 | Double_t z = fRan.Gaus( pos.Z(), sigma ) ; | |
277 | Double_t y = pos.Y() ; | |
278 | ||
279 | newpos.SetX(x) ; | |
280 | newpos.SetY(y) ; | |
281 | newpos.SetZ(z) ; | |
282 | ||
283 | return newpos ; | |
284 | } | |
285 | ||
286 | //____________________________________________________________________________ | |
287 | void AliPHOSv4::MakeRecParticle(const Int_t modid, const TVector3 pos, AliPHOSFastRecParticle & rp) | |
288 | { | |
289 | // Modify the primary particle properties according | |
290 | // 1. the response function of PHOS | |
291 | // 2. the performance of the EMC+PPSD setup | |
292 | ||
293 | Int_t type = MakeType( rp ) ; | |
294 | rp.SetType(type) ; | |
295 | ||
296 | ||
297 | // get the detected energy | |
298 | ||
299 | TLorentzVector momentum ; | |
300 | rp.Momentum(momentum) ; | |
301 | Double_t kineticenergy = TMath::Sqrt( TMath::Power(momentum.E(), 2) - TMath::Power(rp.GetMass(), 2) ) ; | |
302 | Double_t modifiedkineticenergy = MakeEnergy(kineticenergy ) ; | |
303 | Double_t modifiedenergy = TMath::Sqrt( TMath::Power(modifiedkineticenergy, 2) | |
304 | + TMath::Power( rp.GetMass(), 2) ) ; | |
305 | ||
306 | // get the angle of incidence | |
307 | ||
308 | Double_t incidencetheta = 90. * TMath::Pi() /180 - rp.Theta() ; | |
309 | Double_t incidencephi = ( 270 + fGeom->GetPHOSAngle(modid) ) * TMath::Pi() / 180. - rp.Phi() ; | |
310 | ||
311 | // get the detected direction | |
312 | ||
313 | TVector3 modifiedposition = MakePosition(kineticenergy, pos, incidencetheta, incidencephi) ; | |
314 | modifiedposition *= modifiedkineticenergy / modifiedposition.Mag() ; | |
315 | ||
316 | // Set the modified 4-momentum of the reconstructed particle | |
317 | ||
318 | rp.SetMomentum(modifiedposition.X(), modifiedposition.Y(), modifiedposition.Z(), modifiedenergy) ; | |
319 | ||
320 | } | |
321 | ||
322 | //____________________________________________________________________________ | |
323 | Int_t AliPHOSv4::MakeType(AliPHOSFastRecParticle & rp ) | |
324 | { | |
325 | // Generate a particle type using the performance of the EMC+PPSD setup | |
326 | ||
327 | Int_t rv = AliPHOSFastRecParticle::kUNDEFINED ; | |
328 | Int_t charge = (Int_t)rp.GetPDG()->Charge() ; | |
329 | Int_t test ; | |
330 | Float_t ran ; | |
331 | if ( charge != 0 && ( TMath::Abs(rp.GetPdgCode()) != 11 ) ) | |
332 | test = - 1 ; | |
333 | else | |
334 | test = rp.GetPdgCode() ; | |
335 | ||
336 | switch (test) { | |
337 | ||
338 | case 22: // it's a photon | |
339 | ran = fRan.Rndm() ; | |
340 | if ( ran <= 0.5 ) // 50 % | |
341 | rv = AliPHOSFastRecParticle::kGAMMA ; | |
342 | else { | |
343 | ran = fRan.Rndm() ; | |
344 | if( ran <= 0.9498 ) | |
345 | rv = AliPHOSFastRecParticle::kNEUTRALEM ; | |
346 | else | |
347 | rv = AliPHOSFastRecParticle::kNEUTRALHA ; | |
348 | } | |
349 | break ; | |
350 | ||
351 | case 2112: // it's a neutron | |
352 | ran = fRan.Rndm() ; | |
353 | if ( ran <= 0.9998 ) | |
354 | rv = AliPHOSFastRecParticle::kNEUTRALHA ; | |
355 | else | |
356 | rv = AliPHOSFastRecParticle::kNEUTRALEM ; | |
357 | break ; | |
358 | ||
359 | case -2112: // it's a anti-neutron | |
360 | ran = fRan.Rndm() ; | |
361 | if ( ran <= 0.9984 ) | |
362 | rv = AliPHOSFastRecParticle::kNEUTRALHA ; | |
363 | else | |
364 | rv = AliPHOSFastRecParticle::kNEUTRALEM ; | |
365 | break ; | |
366 | ||
367 | case 11: // it's a electron | |
368 | ran = fRan.Rndm() ; | |
369 | if ( ran <= 0.9996 ) | |
370 | rv = AliPHOSFastRecParticle::kELECTRON ; | |
371 | else | |
372 | rv = AliPHOSFastRecParticle::kCHARGEDHA ; | |
373 | break; | |
374 | ||
375 | case -11: // it's a positon | |
376 | ran = fRan.Rndm() ; | |
377 | if ( ran <= 0.9996 ) | |
378 | rv = AliPHOSFastRecParticle::kELECTRON ; | |
379 | else | |
380 | rv = AliPHOSFastRecParticle::kCHARGEDHA ; | |
381 | break; | |
382 | ||
383 | case -1: // it's a charged | |
384 | ran = fRan.Rndm() ; | |
385 | if ( ran <= 0.9996 ) | |
386 | rv = AliPHOSFastRecParticle::kCHARGEDHA ; | |
387 | else | |
388 | rv = AliPHOSFastRecParticle::kGAMMA ; | |
389 | ||
390 | break ; | |
391 | } | |
392 | ||
393 | ||
394 | return rv ; | |
395 | } | |
396 | ||
397 | //___________________________________________________________________________ | |
398 | void AliPHOSv4::ResetPoints() | |
399 | { | |
400 | // This overloads the method in AliDetector | |
401 | ||
402 | ResetFastRecParticles() ; | |
403 | } | |
404 | ||
405 | //___________________________________________________________________________ | |
406 | void AliPHOSv4::ResetFastRecParticles() | |
407 | { | |
408 | // Resets the list of virtual reconstructed particles | |
409 | ||
410 | if (fFastRecParticles) | |
411 | fFastRecParticles->Clear() ; | |
412 | fNRecParticles = 0 ; | |
413 | } | |
414 | ||
415 | //___________________________________________________________________________ | |
416 | void AliPHOSv4::SetBigBox(Int_t index, Float_t value) | |
417 | { | |
418 | // Set the size of the Box describing a PHOS module | |
419 | ||
420 | switch (index) { | |
421 | case 0: | |
422 | fBigBoxX = value ; | |
423 | break ; | |
424 | case 1: | |
425 | fBigBoxY = value ; | |
426 | break ; | |
427 | case 2: | |
428 | fBigBoxZ = value ; | |
429 | break ; | |
430 | } | |
431 | ||
432 | } | |
433 | ||
434 | //____________________________________________________________________________ | |
435 | Double_t AliPHOSv4::SigmaE(Double_t energy) | |
436 | { | |
437 | // Calculates the energy dependent energy resolution | |
438 | ||
439 | Double_t rv = -1 ; | |
440 | ||
441 | rv = TMath::Sqrt( TMath::Power(fResPara1/energy, 2) | |
442 | + TMath::Power(fResPara2/TMath::Sqrt(energy), 2) | |
443 | + TMath::Power(fResPara3, 2) ) ; | |
444 | ||
445 | return rv * energy ; | |
446 | } | |
447 | ||
448 | //____________________________________________________________________________ | |
449 | Double_t AliPHOSv4::SigmaP(Double_t energy, Int_t incidence) | |
450 | { | |
451 | // Calculates the energy dependent position resolution | |
452 | ||
453 | Double_t paraA = fPosParaA0 + fPosParaA1 * incidence ; | |
454 | Double_t paraB = fPosParaB0 + fPosParaB1 * incidence + fPosParaB2 * incidence * incidence ; | |
455 | ||
456 | return ( paraA / TMath::Sqrt(energy) + paraB ) * 0.1 ; // in cm | |
457 | } | |
458 | ||
459 | //____________________________________________________________________________ | |
460 | void AliPHOSv4::StepManager(void) | |
461 | { | |
462 | // Only verifies if the particle reaches PHOS and stops the tracking | |
5cbba5aa | 463 | |
5f20d3fb | 464 | Int_t primary = gAlice->GetPrimary( gAlice->CurrentTrack() ); |
5cbba5aa | 465 | |
5f20d3fb | 466 | TLorentzVector lv ; |
467 | gMC->TrackPosition(lv) ; | |
468 | TVector3 pos = lv.Vect() ; | |
469 | Int_t modid ; | |
470 | gMC->CurrentVolID(modid); | |
471 | ||
5cbba5aa | 472 | Float_t Energy = gMC->Etot() ; //Total energy of current track |
473 | ||
474 | //Calculating mass of current particle | |
475 | TDatabasePDG * PDG = TDatabasePDG::Instance() ; | |
476 | TParticlePDG * partPDG = PDG->GetParticle(gMC->TrackPid()) ; | |
477 | Float_t mass = partPDG->Mass() ; | |
5f20d3fb | 478 | |
5cbba5aa | 479 | if(Energy > mass){ |
480 | pos.SetMag(TMath::Sqrt(Energy*Energy-mass*mass)) ; | |
481 | TLorentzVector pTrack(pos,Energy) ; | |
482 | ||
483 | TParticle * part = new TParticle(gMC->TrackPid(), 0,-1,-1,-1,-1, pTrack, lv) ; | |
484 | ||
485 | AliPHOSFastRecParticle rp(*part) ; | |
486 | rp.SetPrimary(primary) ; | |
487 | ||
488 | // Adds the response of PHOS to the particle | |
489 | MakeRecParticle(modid, pos, rp) ; | |
490 | ||
491 | // add the `track' particle to the FastRecParticles list | |
5f20d3fb | 492 | |
5cbba5aa | 493 | AddRecParticle(rp) ; |
5f20d3fb | 494 | |
5cbba5aa | 495 | part->Delete() ; |
496 | } | |
5f20d3fb | 497 | // stop the track as soon PHOS is reached |
498 | ||
499 | gMC->StopTrack() ; | |
500 | ||
501 | } | |
502 |