Changes for #82873: Module debugging broken (Christian)
[u/mrichter/AliRoot.git] / PWG2 / RESONANCES / AliRsnMother.cxx
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7356f978 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//
18// This class implements a candidate resonance. It has two pointers to its
19// two candidate daughters, whose 4-momenta are combined to obtain the mother
20// invariant mass and other kinematical quantities.
21// This class contains also some methods used to compute kinematical relations
22// between the candidate resonance and other particles.
23//
24// authors: A. Pulvirenti (alberto.pulvirenti@ct.infn.it)
25// M. Vala (martin.vala@cern.ch)
26//
27////////////////////////////////////////////////////////////////////////////////
747592c1 28
2dab9030 29#include <Riostream.h>
4820b1ae 30#include <TVector3.h>
747592c1 31
ec927a7d 32#include "AliAODMCParticle.h"
33#include "AliMCParticle.h"
d7712d44 34#include "AliRsnEvent.h"
35
2dab9030 36#include "AliRsnMother.h"
37
38ClassImp(AliRsnMother)
39
f34f960b 40//__________________________________________________________________________________________________
2a1c7696 41AliRsnMother::AliRsnMother(const AliRsnMother &obj) :
42 TObject(obj),
d7712d44 43 fRefEvent(obj.fRefEvent),
2a1c7696 44 fSum(obj.fSum),
110620ce 45 fSumMC(obj.fSumMC),
46 fRef(obj.fRef),
47 fRefMC(obj.fRefMC)
2dab9030 48{
49//
50// Copy constructor.
2dab9030 51// Does not duplicate pointers.
52//
53
2a1c7696 54 Int_t i;
55 for (i = 0; i < 2; i++) fDaughter[i] = obj.fDaughter[i];
2dab9030 56}
57
f34f960b 58//__________________________________________________________________________________________________
2dab9030 59AliRsnMother& AliRsnMother::operator=(const AliRsnMother &obj)
60{
61//
62// Assignment operator.
2dab9030 63// Does not duplicate pointers.
64//
65
2a1c7696 66 fSum = obj.fSum;
f34f960b 67 fRef = obj.fRef;
110620ce 68 fSumMC = obj.fSumMC;
69 fRefMC = obj.fRefMC;
d7712d44 70 fRefEvent = obj.fRefEvent;
f34f960b 71 fDaughter[0] = obj.fDaughter[0];
72 fDaughter[1] = obj.fDaughter[1];
73
2a1c7696 74 return (*this);
2dab9030 75}
76
f34f960b 77//__________________________________________________________________________________________________
2dab9030 78AliRsnMother::~AliRsnMother()
79{
80//
81// Desctructor.
82// Does nothing, since pointers are not created in this class.
83//
84}
85
f34f960b 86//_______________________________________________________________________________________________________________________
87void AliRsnMother::Reset()
2dab9030 88{
89//
7356f978 90// Resets the mother, zeroing all data members.
2dab9030 91//
92
2a1c7696 93 Int_t i;
94 for (i = 0; i < 2; i++) fDaughter[i] = 0x0;
d7712d44 95 fRefEvent = 0x0;
f34f960b 96 fSum.SetXYZM(0.0, 0.0, 0.0, 0.0);
97 fRef.SetXYZM(0.0, 0.0, 0.0, 0.0);
2dab9030 98}
99
f34f960b 100//__________________________________________________________________________________________________
101Int_t AliRsnMother::CommonMother() const
d7712d44 102{
103//
f34f960b 104// If MC info is available, checks if the two tracks in the pair have the same mother.
105// If the mother label is the same, the function returns the PDG code of mother,
106// otherwise it returns 0.
107// The two arguments passed by reference contain the GEANT labels of the mother
108// of the two particles to which the two daughters point. This is for being able
109// to check if they are really coming from a resonance (indexes >= 0) or not.
d7712d44 110//
111
f34f960b 112 Int_t m1 = fDaughter[0]->GetMother();
113 Int_t m2 = fDaughter[1]->GetMother();
114 Int_t out = 0;
115
116 // a true mother makes sense only if both mothers
117 // are not-negative and equal
118 if (m1 >= 0 && m2 >= 0 && m1 == m2) {
119 out = TMath::Abs(fDaughter[0]->GetMotherPDG());
120 AliDebugClass(1, Form("Mothers are: %d %d --> EQUAL (PDG = %d)", m1, m2, out));
121 }
d7712d44 122
f34f960b 123 return out;
d7712d44 124}
125
f34f960b 126//__________________________________________________________________________________________________
d7712d44 127Double_t AliRsnMother::AngleToLeading(Bool_t &success)
128{
129//
130// Compute the angle betwee this and the leading particls
131// of the reference event (if this was set properly).
132// In case one of the two daughters is the leading, return
133// a meaningless value, in order to skip this pair.
134// if second argument is kTRUE, use MC values.
135//
136
137 if (!fRefEvent) {
138 success = kFALSE;
139 return -99.0;
140 }
141
142 Int_t id1 = fDaughter[0]->GetID();
143 Int_t id2 = fDaughter[1]->GetID();
f34f960b 144 Int_t idL = fRefEvent->GetLeadingIndex();
d7712d44 145
146 if (id1 == idL || id2 == idL) {
147 success = kFALSE;
148 return -99.0;
149 }
150
f34f960b 151 AliRsnDaughter leading = fRefEvent->GetDaughter(idL, kFALSE);
d7712d44 152 AliVParticle *ref = leading.GetRef();
153 Double_t angle = ref->Phi() - fSum.Phi();
154
155 //return angle w.r.t. leading particle in the range -pi/2, 3/2pi
156 while (angle >= 1.5 * TMath::Pi()) angle -= 2 * TMath::Pi();
157 while (angle < -0.5 * TMath::Pi()) angle += 2 * TMath::Pi();
158 success = kTRUE;
159
160 return angle;
161}
162
f34f960b 163//__________________________________________________________________________________________________
164void AliRsnMother::ComputeSum(Double_t mass0, Double_t mass1, Double_t motherMass)
165{
166//
167// Sets the masses for the 4-momenta of the daughters and then
168// sums them, taking into account that the space part is set to
169// each of them when the reference object is set (see AliRsnDaughter::SetRef)
170//
171
172 fDaughter[0]->FillP(mass0);
173 fDaughter[1]->FillP(mass1);
174
175 // sum
176 fSum = fDaughter[0]->Prec() + fDaughter[1]->Prec();
177 fSumMC = fDaughter[0]->Psim() + fDaughter[1]->Psim();
178
179 // reference
180 fRef.SetXYZM(fSum.X(), fSum.Y(), fSum.Z(), motherMass);
181 fRefMC.SetXYZM(fSumMC.X(), fSumMC.Y(), fSumMC.Z(), motherMass);
182}
183
184//__________________________________________________________________________________________________
2e521c29 185Double_t AliRsnMother::CosThetaStar(Bool_t first, Bool_t useMC)
cadcd9e0 186{
7356f978 187//
188// Computes the cosine of theta*, which is the angle of one of the daughters
189// with respect to the total momentum of the resonance, in its rest frame.
190// The arguments are needed to choose which of the daughters one want to use
191// and if reconstructed or MC momentum must be used.
192// [Contribution from Z. Feckova]
193//
194
f34f960b 195 TLorentzVector &mother = Sum(useMC);
196 TLorentzVector &daughter0 = (first ? fDaughter[0]->P(useMC) : fDaughter[1]->P(useMC));
197 TLorentzVector &daughter1 = (first ? fDaughter[1]->P(useMC) : fDaughter[0]->P(useMC));
2a1c7696 198 TVector3 momentumM(mother.Vect());
199 TVector3 normal(mother.Y() / momentumM.Mag(), -mother.X() / momentumM.Mag(), 0.0);
200
201 // Computes first the invariant mass of the mother
7356f978 202 Double_t mass0 = fDaughter[0]->P(useMC).M();
203 Double_t mass1 = fDaughter[1]->P(useMC).M();
204 Double_t p0 = daughter0.Vect().Mag();
205 Double_t p1 = daughter1.Vect().Mag();
206 Double_t E0 = TMath::Sqrt(mass0 * mass0 + p0 * p0);
207 Double_t E1 = TMath::Sqrt(mass1 * mass1 + p1 * p1);
208 Double_t MotherMass = TMath::Sqrt((E0 + E1) * (E0 + E1) - (p0 * p0 + 2.0 * daughter0.Vect().Dot(daughter1.Vect()) + p1 * p1));
2a1c7696 209 MotherMass = fSum.M();
210
211 // Computes components of beta
212 Double_t betaX = -mother.X() / mother.E();
213 Double_t betaY = -mother.Y() / mother.E();
214 Double_t betaZ = -mother.Z() / mother.E();
215
216 // Computes Lorentz transformation of the momentum of the first daughter
217 // into the rest frame of the mother and theta*
218 daughter0.Boost(betaX, betaY, betaZ);
219 TVector3 momentumD = daughter0.Vect();
220
221 Double_t cosThetaStar = normal.Dot(momentumD) / momentumD.Mag();
222
223 return cosThetaStar;
cadcd9e0 224}
225
f34f960b 226//__________________________________________________________________________________________________
2dab9030 227void AliRsnMother::PrintInfo(const Option_t * /*option*/) const
228{
229//
230// Print some info of the pair.
231// The options are passed to the AliRsnDaughter::Print() method
232//
233
2a1c7696 234 AliInfo("======== BEGIN PAIR INFO ===========");
235 AliInfo("Track #1");
236 fDaughter[0]->Print();
237 AliInfo("Track #2");
238 fDaughter[1]->Print();
239 AliInfo("========= END PAIR INFO ===========");
2dab9030 240}
241
f34f960b 242//__________________________________________________________________________________________________
0206329d 243Bool_t AliRsnMother::CheckPair(Bool_t checkMC) const
2dab9030 244{
245//
246// Checks that the pair is well initialized:
247// - both daughters are good pointers
248// - if MC is required, both daughters have a MC reference
249//
250
2a1c7696 251 if (!fDaughter[0] || !fDaughter[1]) {
252 AliError("One of the two tracks is NULL in this pair!");
2dab9030 253 return kFALSE;
2a1c7696 254 }
255
0206329d 256 if (checkMC) {
2a1c7696 257 if (fDaughter[0]->GetRefMC() == 0x0 || fDaughter[1]->GetRefMC() == 0x0) {
258 AliError("Required MC info but not all MC refs are available");
259 return kFALSE;
260 }
261 }
262
263 return kTRUE;
2dab9030 264}