Merge branch 'master' of https://git.cern.ch/reps/AliRoot
[u/mrichter/AliRoot.git] / MUON / AliMUONPairLight.cxx
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55fd51b0 1/**************************************************************************
2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
3 * SigmaEffect_thetadegrees *
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 purpeateose. It is *
13 * provided "as is" without express or implied warranty. *
14 **************************************************************************/
15
16/* $Id$ */
17
3d1463c8 18//-----------------------------------------------------------------------------
55fd51b0 19//This class was prepared by INFN Cagliari, July 2006
20//(authors: H.Woehri, A.de Falco)
21//
22// Compact information for the generated muon pairs in the MUON arm
23// useful at the last stage of the analysis chain
24// Pairs are built with two AliMUONTrackLight objects
25// Using the class AliMUONTrackLight this class combines the decay
26// information ("history") of the reconstructed tracks and fills
27// a series of flags for the formed reconstructed dimuon:
28// fIsCorrelated, fCreationProcess, fIsFeedDown, ...
29// for information about the dimuon, use PrintInfo with the appropriate
30// printflag
31// To be used together with AliMUONTrackLight
3d1463c8 32//-----------------------------------------------------------------------------
55fd51b0 33
34
35//MUON classes
36#include "AliMUONPairLight.h"
37//Root classes
38#include "TString.h"
39
40ClassImp(AliMUONPairLight)
41
42//====================================
43AliMUONPairLight::AliMUONPairLight() :
44 TObject(),
45 fMu0(),
46 fMu1(),
47 fCreationProcess(-999),
48 fIsCorrelated(kFALSE),
49 fCauseOfCorrelation (-1),
50 fIsFeedDown(kFALSE)
51{
52 /// default constructor
53 ;
54}
55
56//====================================
57
58AliMUONPairLight::AliMUONPairLight(AliMUONPairLight &dimuCopy)
59 : TObject(dimuCopy),
60 fMu0(dimuCopy.fMu0),
0060b2f7 61 fMu1(dimuCopy.fMu1),
55fd51b0 62 fCreationProcess(dimuCopy.fCreationProcess),
63 fIsCorrelated(dimuCopy.fIsCorrelated),
64 fCauseOfCorrelation (dimuCopy.fCauseOfCorrelation),
65 fIsFeedDown(dimuCopy.fIsFeedDown)
66{
67/// copy constructor
68/// fMu0 = AliMUONTrackLight(dimuCopy.fMu0);
69/// fMu1 = AliMUONTrackLight(dimuCopy.fMu1);
70/// fIsCorrelated = dimuCopy.fIsCorrelated;
71/// fCauseOfCorrelation = dimuCopy.fCauseOfCorrelation;
72/// fCreationProcess = dimuCopy.fCreationProcess;
73/// fIsFeedDown = dimuCopy.fIsFeedDown;
74 ;
75}
76
77//====================================
78
79AliMUONPairLight::~AliMUONPairLight(){
80 /// destructor
81}
82
83//====================================
84
e733e3dd 85AliMUONPairLight& AliMUONPairLight::operator=(const AliMUONPairLight& dimuCopy)
86{
87 // check assignment to self
88 if (this == &dimuCopy) return *this;
89
90 // base class assignment
91 TObject::operator=(dimuCopy);
92
93 // assignment operator
94 fMu0 = dimuCopy.fMu0;
95 fMu1 = dimuCopy.fMu1;
96 fCreationProcess = dimuCopy.fCreationProcess;
97 fIsCorrelated = dimuCopy.fIsCorrelated;
98 fCauseOfCorrelation = dimuCopy.fCauseOfCorrelation;
99 fIsFeedDown = dimuCopy.fIsFeedDown;
72421d27 100
101 return *this;
e733e3dd 102}
103
104//====================================
105
55fd51b0 106Bool_t AliMUONPairLight::IsAResonance(){
107 /// checks if muon pair comes from a resonance decay
108 if (!fIsCorrelated) return kFALSE; //if muons not correlated, cannot be a resonance
109 //if muons are correlated, check if the PDG of the
110 //common mother is a resonance
b88403f3 111 Int_t nparents0 = fMu0.GetNParents();
112 Int_t nparents1 = fMu1.GetNParents();
55fd51b0 113
b88403f3 114 Int_t minP = TMath::Min(nparents0, nparents1);
115 for (Int_t i = 0 ; i < minP; i++) {
116 if (fMu0.IsMotherAResonance(nparents0-1-i) && fMu1.IsMotherAResonance(nparents1-1-i) &&
117 fMu0.GetParentPythiaLine(nparents0-1-i)==fMu1.GetParentPythiaLine(nparents1-1-i)) {
118 if (nparents0-1-i) SetFeedDown(nparents0-1-i);
119 return kTRUE;
120 }
121 }
122 return kFALSE;
55fd51b0 123}
124
125//====================================
126
127AliMUONTrackLight* AliMUONPairLight::GetMuon(Int_t index) {
128 /// return muon 0 or 1
129 if (index==0) return &fMu0;
130 else if (index==1) return &fMu1;
131 else{ printf ("Index can be either 0 or 1\n"); return 0;}
132 // else return &fMu1;
133}
134
135//====================================
136
137Int_t AliMUONPairLight::GetMuonMotherPDG(Int_t imuon, Int_t mother) {
138 /// return muon mother pdg code
139 if (imuon==0) return fMu0.GetParentPDGCode(mother);
140 else if (imuon==1) return fMu1.GetParentPDGCode(mother);
141 else { printf ("Index must be only 0 or 1\n"); return -999; }
142}
143
144//====================================
145void AliMUONPairLight::SetProcess(){
146 /// finds the process related to the muon pair (open charm/beauty, resonance,
147 /// uncorrelated...)
b88403f3 148
55fd51b0 149 AliMUONTrackLight *mu1 = &fMu0;
150 AliMUONTrackLight *mu2 = &fMu1;
151
55fd51b0 152 // check if the two muons are correlated
153 // first check if they come from the same hadron (resonance or beauty/charm meson)
154 Int_t npar1 = mu1->GetNParents();
155 Int_t npar2 = mu2->GetNParents();
55fd51b0 156 for (Int_t imoth1 = npar1-1; imoth1>=0; imoth1--) {
157 Int_t lineMo1 = mu1->GetParentPythiaLine(imoth1);
55fd51b0 158 for (Int_t imoth2 = npar2-1; imoth2>=0; imoth2--) {
159 Int_t lineMo2 = mu2->GetParentPythiaLine(imoth2);
160 if(lineMo1 == lineMo2) {
b88403f3 161 //reject "diquark" mothers
162 if(mu1->IsDiquark(mu1->GetParentPDGCode(imoth1)))return;
163// if(IsDiquark(mu1->GetParentPDGCode(imoth1))) return;
55fd51b0 164 this->SetCorrelated(kTRUE);
165 this->SetCauseOfCorrelation(mu1->GetParentPDGCode(imoth1));
166 if(!IsAResonance()) fCreationProcess = 3;
167 else fCreationProcess = -1;
b88403f3 168 return;
55fd51b0 169 }
170 }
91e620e2 171 }
172
173 //now, check if we have a correlated pi/K:
174 if(this->IsDimuonFromCorrPiK()){
175 this->SetCorrelated(kTRUE);
176 this->SetCauseOfCorrelation(mu1->GetParentPDGCode(0));
177 fCreationProcess = -1;
178 }
179
55fd51b0 180 // if Open Beauty/Charm we can have 3 creation processes
181 // (pair creation [0], gluon splitting [1] or flavour excitation [2])
55fd51b0 182 // 1.) gluon splitting: gluon (stored with index 2, id=21) must be the same
b88403f3 183 Int_t flavPar1 = mu1->GetParentFlavour(0);
184 Int_t flavPar2 = mu2->GetParentFlavour(0);
185 for (Int_t imoth1 = 0; imoth1 < 4; imoth1++) {
186 Int_t lineMo1 = mu1->GetQuarkPythiaLine(imoth1);
187 for (Int_t imoth2 = 0; imoth2 < 4; imoth2++) {
188 Int_t lineMo2 = mu2->GetQuarkPythiaLine(imoth2);
189 if(lineMo1 == lineMo2 && mu1->GetQuarkPDGCode(imoth1) == 21) {
190 //now, check also that the string fragmented into two hadrons
191 //of the same flavour (string usually splits into many hadrons
192 //among which there are mostly soft particles)
193 if(flavPar1 == flavPar2){
194 this->SetCorrelated(kTRUE);
195 if(GetCauseOfCorrelation() == -1)
196 this->SetCauseOfCorrelation(mu1->GetQuarkPDGCode(imoth1));
197
198 fCreationProcess = 1;
199 return;
200 }
201 }
55fd51b0 202 }
55fd51b0 203 }
91e620e2 204
55fd51b0 205 Int_t line1 = mu1->GetQuarkPythiaLine(2); //[2] ... very first quark
206 Int_t line2 = mu2->GetQuarkPythiaLine(2);
b88403f3 207
208 Int_t line6or7[2] = {-1, -1}; //holds the index of quark in line 6 or 7
209 Int_t flavourLine6or7[2] = {-1, -1};
210 // 2.) pair creation: if pythia line 6 of one track *and* pythia line 7 of second track
211 // are filled with a Q and Qbar
212 for (Int_t imoth1 = 3; imoth1>=0; imoth1--) {
213 Int_t lineMo1 = mu1->GetQuarkPythiaLine(imoth1);
214 Int_t flavour1 = TMath::Abs(mu1->GetQuarkPDGCode(imoth1));
215 if(lineMo1 == 6 || lineMo1 == 7){ //track 0 has a mother in line 6 or 7
216 line6or7[0] = imoth1;
217 flavourLine6or7[0] = flavour1;
218 }
219 for (Int_t imoth2 = 3; imoth2>=0; imoth2--) {
220 Int_t lineMo2 = mu2->GetQuarkPythiaLine(imoth2);
221 Int_t flavour2 = TMath::Abs(mu2->GetQuarkPDGCode(imoth2));
222 if(lineMo2 == 6 || lineMo2 == 7){ //track 1 has a mother in line 6 or 7
223 line6or7[1] = imoth2;
224 flavourLine6or7[1] = flavour2;
225 }
226 if((line6or7[0] > 0 && line6or7[1] > 0) && //both tracks must have an entry in line 6 or 7
227 (flavourLine6or7[0] == 4 || flavourLine6or7[0] == 5) && //this entry must be a c or b quark
228 (flavourLine6or7[1] == 4 || flavourLine6or7[1] == 5) && // == " ==
229 (flavPar1 == flavPar2)){ //make sure that the first hadronised parents of the 2 tracks are of the same flavour
230 this->SetCorrelated(kTRUE);
231 fCreationProcess = 0;
232 return;
233 }
55fd51b0 234 }
235 }
236
91e620e2 237 // 3.)flavour excitation: if pythia line 6 of one track *and* pythia line 7 of second track
238 // are filled with a Q and Qbar and if in addition there is another heavy quark in line(s) 4 and/or 5
b88403f3 239 Int_t line2or3[2] = {-1, -1}; //holds the index of g/q in line 2 or 3
240 Int_t flavourLine2or3[2] = {-1, -1};
241 for (Int_t imoth1 = 3; imoth1>=0; imoth1--) {
242 Int_t lineMo1 = mu1->GetQuarkPythiaLine(imoth1);
243 Int_t flavour1 = TMath::Abs(mu1->GetQuarkPDGCode(imoth1));
244 if(lineMo1 == 2 || lineMo1 == 3){ //track 0 has a mother in line 2 or 3
245 line2or3[0] = imoth1;
246 flavourLine2or3[0] = flavour1;
247 }
248 for (Int_t imoth2 = 3; imoth2>=0; imoth2--) {
249 Int_t lineMo2 = mu2->GetQuarkPythiaLine(imoth2);
250 Int_t flavour2 = TMath::Abs(mu2->GetQuarkPDGCode(imoth2));
251 if(lineMo2 == 2 || lineMo2 == 3){ //track 1 has a mother in line 2 or 3
252 line2or3[1] = imoth2;
253 flavourLine2or3[1] = flavour2;
254 }
255 if(((line6or7[0] > 0 && (flavourLine6or7[0] == 4 || flavourLine6or7[0] == 5)) && //first track has Q in line 6 or 7
256 (line2or3[1] > 0 && (flavourLine2or3[1] == 21 || flavourLine2or3[1] < 10))) || //second track has a g/q in line 2 or 3
257 ((line6or7[1] > 0 && (flavourLine6or7[1] == 4 || flavourLine6or7[1] == 5)) && //or the same,
258 (line2or3[0] > 0 && (flavourLine2or3[0] == 21 || flavourLine2or3[0] < 10)))){ // swapping the track's indices
259 //now, check also that the string fragmented into two hadrons
260 //of the same flavour (string usually splits into many hadrons
261 //among which there are mostly soft particles)
262 if(flavPar1 == flavPar2){
263 this->SetCorrelated(kTRUE);
264 fCreationProcess = 2;
265 return;
266 }
267 }
268 }
269 }
270
271 //now flag (rare) processes in which only the incoming parton in line 2 or 3
272 //radiates a gluon which produces a QQbar pair:
273 //exclude the light quarks
274 if(line1 == line2 && (line1 == 2 || line1 == 3)){
275 if((TMath::Abs(mu1->GetQuarkPDGCode(1)) == 4 && TMath::Abs(mu2->GetQuarkPDGCode(1)) == 4) ||
276 (TMath::Abs(mu1->GetQuarkPDGCode(1)) == 5 && TMath::Abs(mu2->GetQuarkPDGCode(1)) == 5)){
277
278 //now, check also that the string fragmented into two hadrons
279 //of the same flavour (string usually splits into many hadrons
280 //among which there are mostly soft particles)
281 if(flavPar1 == flavPar2){
282
283 this->SetCorrelated(kTRUE);
284 fCreationProcess = 1;
285 if(GetCauseOfCorrelation() == -1){
286 this->SetCauseOfCorrelation(mu1->GetQuarkPDGCode(1));
287 }
288 return;
289 }
290 }
55fd51b0 291 }
91e620e2 292
293 //in initial-state-radiation produced QQbar events the "mother quark"
294 //is acknowledged as the second quark [1] and sits in line 2 or 3
295 //is part of gluon splitting
296 line1 = mu1->GetQuarkPythiaLine(1); //[1] ... direct mother quark of outgoing quark in [0]
297 line2 = mu2->GetQuarkPythiaLine(1);
298 if(line1 == line2 && (line1 == 2 || line1 == 3)){
299 if((TMath::Abs(mu1->GetQuarkPDGCode(0)) == 4 && TMath::Abs(mu2->GetQuarkPDGCode(0)) == 4) ||
300 (TMath::Abs(mu1->GetQuarkPDGCode(0)) == 5 && TMath::Abs(mu2->GetQuarkPDGCode(0)) == 5)){
301
302 //now, check also that the string fragmented into two hadrons
303 //of the same flavour (string usually splits into many hadrons
304 //among which there are mostly soft particles)
305 if(flavPar1 == flavPar2){
306
307 this->SetCorrelated(kTRUE);
308 fCreationProcess = 1;
309 if(GetCauseOfCorrelation() == -1){
310 this->SetCauseOfCorrelation(mu1->GetQuarkPDGCode(1)); //should be flagged as initial state radiation?
311 }
312 return;
313 }
314 }
315 }
316
317 //in final-state-radiation produced QQbar events the "mother quark"
318 //is acknowledged as the first quark [1] and sits in line 6 or 7
319 //is part of gluon splitting
320 line1 = mu1->GetQuarkPythiaLine(1); //[1] ... direct mother quark
321 line2 = mu2->GetQuarkPythiaLine(1);
322 if(line1 == line2 && (line1 == 6 || line1 == 7)){
323 if((TMath::Abs(mu1->GetQuarkPDGCode(0)) == 4 && TMath::Abs(mu2->GetQuarkPDGCode(0)) == 4) ||
324 (TMath::Abs(mu1->GetQuarkPDGCode(0)) == 5 && TMath::Abs(mu2->GetQuarkPDGCode(0)) == 5)){
325
326 //now, check also that the string fragmented into two hadrons
327 //of the same flavour (string usually splits into many hadrons
328 //among which there are mostly soft particles)
329 if(flavPar1 == flavPar2){
330
331 this->SetCorrelated(kTRUE);
332 fCreationProcess = 1;
333 if(GetCauseOfCorrelation() == -1){
334 this->SetCauseOfCorrelation(mu1->GetQuarkPDGCode(1));
335 }
336 return;
337 }
338 }
339 }
55fd51b0 340}
341
342//====================================
c3aca76f 343void AliMUONPairLight::SetMuons(const AliMUONTrackLight& mu0, const AliMUONTrackLight& mu1){
55fd51b0 344 /// set the two muons
345 fMu0 = mu0;
346 fMu1 = mu1;
347 this->SetProcess();
348}
349
350//====================================
57e2ad1a 351void AliMUONPairLight::PrintInfo(const Option_t* opt){
55fd51b0 352 /// print information about muon pairs
353 /// Options:
354 /// - "H" single muons' decay histories
355 /// - "K" dimuon kinematics
356 /// - "F" dimuon flags
357 /// - "A" all variables
358 TString options(opt);
359 options.ToUpper();
360
361 if(options.Contains("H") || options.Contains("A")){//muon decay histories
362
363 AliMUONTrackLight *mu1 = &fMu0;
364 AliMUONTrackLight *mu2 = &fMu1;
365
366 printf("========= History =======================\n");
367 printf("first muon");
368 mu1->PrintInfo("H");
369 printf("second muon");
370 mu2->PrintInfo("H");
371 printf("=========================================\n");
372 }
373 if(options.Contains("F") || options.Contains("A")){//flags
374 printf("the flags set for this muon pair are:\n");
375 printf("=====================================\n");
376 if(this->IsOneTrackNotAMuon()) printf("(*) one rec. track is not a muon\n");
377 fIsCorrelated ? printf("(*) it is a correlated pair\n") : printf("(*) it is not a correlated pair\n");
378 if(IsOpenCharm()) printf("(*) correlated open charm: ");
379 if(IsOpenBeauty()) printf("(*) correlated open beauty: ");
380 if(IsOpenCharm() || IsOpenBeauty()){
381 switch(fCreationProcess){
382 case 0:
383 printf("pair creation");
384 break;
385 case 1:
386 printf("gluon splitting");
387 break;
388 case 2:
389 printf("flavour excitation");
390 break;
391 case 3:
392 printf("both muons come from same fragmented mother");
393 break;
394 }
395 if(this->GetMuon(0)->GetOscillation() || this->GetMuon(1)->GetOscillation())
396 printf("... where oscillation occured\n");
397 else{
398 if(IsOpenBeauty())
399 printf(" (no oscillation)\n");
400 else
401 printf("\n");
402 }
403 }
b88403f3 404 IsAResonance() ? printf("(*) it is a resonance: %d\n", this->GetMuonMotherPDG(0, fIsFeedDown)) : printf("(*) it is not a resonance\n");
405 fIsFeedDown ? printf("(*) mother has feed-down: %d --> %d\n", this->GetMuonMotherPDG(0,fMu0.GetNParents()-2), this->GetMuonMotherPDG(0,fMu0.GetNParents()-1)) : printf("(*) no feed-down\n");
55fd51b0 406 printf("=====================================\n");
407 }
408 if(options.Contains("K") || options.Contains("A")){//dimuon kinematics
409 Double_t *vtx = this->GetMuon(0)->GetVertex();
410 TLorentzVector momRec = this->GetPRec();
411 TLorentzVector momGen = this->GetPGen();
412 printf("the dimuon charge is %d\n", this->GetCharge());
413 printf("primary Vertex: Vx = %1.3f, Vy = %1.3f, Vz = %1.3f\n", vtx[0], vtx[1], vtx[2]);
414 printf("Generated: Px = %1.3f, Py = %1.3f, Pz = %1.3f\n", momGen.Px(), momGen.Py(), momGen.Pz());
415 printf("Reconstructed: Px = %1.3f, Py = %1.3f, Pz = %1.3f\n", momRec.Px(), momRec.Py(), momRec.Pz());
416 //rapidity, pT, angles, ...
91e620e2 417 printf("Rec. variables: mass %1.3f, pT %1.3f, pseudo-rapidity %1.3f, openingAngle %1.3f (%1.3f degree), theta %1.3f (%1.3f degree), phi %1.3f (%1.3f degree)\n",
418 momRec.M(), momRec.Pt(), momRec.Eta(),
55fd51b0 419 TMath::Pi()/180.*this->GetOpeningAngle(), this->GetOpeningAngle(),
420 momRec.Theta(), 180./TMath::Pi() * momRec.Theta(),
421 momRec.Phi(), 180./TMath::Pi() * momRec.Phi());
422 }
423}
424
b88403f3 425//====================================
55fd51b0 426Double_t AliMUONPairLight::GetOpeningAngle() {
b88403f3 427 /// opening angle between the two muons in the lab frame (in degrees)
55fd51b0 428 TLorentzVector pRecMu0 = fMu0.GetPRec();
429 TLorentzVector pRecMu1 = fMu1.GetPRec();
430 TVector3 pRecMu03 = pRecMu0.Vect();
431 TVector3 pRecMu13 = pRecMu1.Vect();
432 Double_t scalar = pRecMu03.Dot(pRecMu13);
433 Double_t modMu0 = pRecMu03.Mag();
434 Double_t modMu1 = pRecMu13.Mag();
435 Double_t theta = (TMath::ACos(scalar/(modMu0*modMu1)))*(180./TMath::Pi());
436 return theta;
437}
91e620e2 438//================================================
439Bool_t AliMUONPairLight::IsDimuonFromCorrPiK(){
440 ///check if we have a correlated pi/K
441
442 AliMUONTrackLight *mu0 = this->GetMuon(0), *mu1 = this->GetMuon(1);
443 Bool_t fromSameLine = kFALSE;
444 if (mu0->IsParentPionOrKaon() &&
445 mu1->IsParentPionOrKaon() &&
446 mu1->GetQuarkPythiaLine() == mu0->GetQuarkPythiaLine()
447 ) fromSameLine = kTRUE;
448
449 return fromSameLine;
450}