Added new cuts for (TPC pid & TOF match) and (TPC pid & TOF veto) for K* pA analysis
[u/mrichter/AliRoot.git] / PWGLF / 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//__________________________________________________________________________________________________
61f275d1 59AliRsnMother &AliRsnMother::operator=(const AliRsnMother &obj)
2dab9030 60{
61//
62// Assignment operator.
2dab9030 63// Does not duplicate pointers.
64//
61f275d1 65 if (this == &obj)
66 return *this;
67
68 fSum = obj.fSum;
69 fRef = obj.fRef;
70 fSumMC = obj.fSumMC;
71 fRefMC = obj.fRefMC;
72 fRefEvent = obj.fRefEvent;
73 fDaughter[0] = obj.fDaughter[0];
74 fDaughter[1] = obj.fDaughter[1];
75
76 return (*this);
2dab9030 77}
78
f34f960b 79//__________________________________________________________________________________________________
2dab9030 80AliRsnMother::~AliRsnMother()
81{
82//
83// Desctructor.
84// Does nothing, since pointers are not created in this class.
85//
86}
87
f34f960b 88//_______________________________________________________________________________________________________________________
89void AliRsnMother::Reset()
2dab9030 90{
91//
7356f978 92// Resets the mother, zeroing all data members.
2dab9030 93//
94
2a1c7696 95 Int_t i;
96 for (i = 0; i < 2; i++) fDaughter[i] = 0x0;
d7712d44 97 fRefEvent = 0x0;
f34f960b 98 fSum.SetXYZM(0.0, 0.0, 0.0, 0.0);
99 fRef.SetXYZM(0.0, 0.0, 0.0, 0.0);
2dab9030 100}
101
f34f960b 102//__________________________________________________________________________________________________
103Int_t AliRsnMother::CommonMother() const
d7712d44 104{
105//
f34f960b 106// If MC info is available, checks if the two tracks in the pair have the same mother.
107// If the mother label is the same, the function returns the PDG code of mother,
108// otherwise it returns 0.
109// The two arguments passed by reference contain the GEANT labels of the mother
61f275d1 110// of the two particles to which the two daughters point. This is for being able
f34f960b 111// to check if they are really coming from a resonance (indexes >= 0) or not.
d7712d44 112//
113
f34f960b 114 Int_t m1 = fDaughter[0]->GetMother();
115 Int_t m2 = fDaughter[1]->GetMother();
116 Int_t out = 0;
61f275d1 117
f34f960b 118 // a true mother makes sense only if both mothers
119 // are not-negative and equal
120 if (m1 >= 0 && m2 >= 0 && m1 == m2) {
121 out = TMath::Abs(fDaughter[0]->GetMotherPDG());
122 AliDebugClass(1, Form("Mothers are: %d %d --> EQUAL (PDG = %d)", m1, m2, out));
61f275d1 123 }
124
f34f960b 125 return out;
d7712d44 126}
127
f34f960b 128//__________________________________________________________________________________________________
d7712d44 129Double_t AliRsnMother::AngleToLeading(Bool_t &success)
130{
131//
132// Compute the angle betwee this and the leading particls
133// of the reference event (if this was set properly).
134// In case one of the two daughters is the leading, return
135// a meaningless value, in order to skip this pair.
136// if second argument is kTRUE, use MC values.
137//
138
139 if (!fRefEvent) {
140 success = kFALSE;
141 return -99.0;
142 }
61f275d1 143
d7712d44 144 Int_t id1 = fDaughter[0]->GetID();
145 Int_t id2 = fDaughter[1]->GetID();
f34f960b 146 Int_t idL = fRefEvent->GetLeadingIndex();
61f275d1 147
d7712d44 148 if (id1 == idL || id2 == idL) {
149 success = kFALSE;
150 return -99.0;
151 }
61f275d1 152
f34f960b 153 AliRsnDaughter leading = fRefEvent->GetDaughter(idL, kFALSE);
d7712d44 154 AliVParticle *ref = leading.GetRef();
155 Double_t angle = ref->Phi() - fSum.Phi();
61f275d1 156
d7712d44 157 //return angle w.r.t. leading particle in the range -pi/2, 3/2pi
158 while (angle >= 1.5 * TMath::Pi()) angle -= 2 * TMath::Pi();
159 while (angle < -0.5 * TMath::Pi()) angle += 2 * TMath::Pi();
160 success = kTRUE;
61f275d1 161
d7712d44 162 return angle;
163}
164
f34f960b 165//__________________________________________________________________________________________________
166void AliRsnMother::ComputeSum(Double_t mass0, Double_t mass1, Double_t motherMass)
167{
168//
169// Sets the masses for the 4-momenta of the daughters and then
170// sums them, taking into account that the space part is set to
171// each of them when the reference object is set (see AliRsnDaughter::SetRef)
172//
173
174 fDaughter[0]->FillP(mass0);
175 fDaughter[1]->FillP(mass1);
176
177 // sum
178 fSum = fDaughter[0]->Prec() + fDaughter[1]->Prec();
179 fSumMC = fDaughter[0]->Psim() + fDaughter[1]->Psim();
61f275d1 180
f34f960b 181 // reference
182 fRef.SetXYZM(fSum.X(), fSum.Y(), fSum.Z(), motherMass);
183 fRefMC.SetXYZM(fSumMC.X(), fSumMC.Y(), fSumMC.Z(), motherMass);
184}
185
186//__________________________________________________________________________________________________
2e521c29 187Double_t AliRsnMother::CosThetaStar(Bool_t first, Bool_t useMC)
cadcd9e0 188{
7356f978 189//
190// Computes the cosine of theta*, which is the angle of one of the daughters
191// with respect to the total momentum of the resonance, in its rest frame.
192// The arguments are needed to choose which of the daughters one want to use
193// and if reconstructed or MC momentum must be used.
194// [Contribution from Z. Feckova]
195//
196
f34f960b 197 TLorentzVector &mother = Sum(useMC);
198 TLorentzVector &daughter0 = (first ? fDaughter[0]->P(useMC) : fDaughter[1]->P(useMC));
74d60285 199// TLorentzVector &daughter1 = (first ? fDaughter[1]->P(useMC) : fDaughter[0]->P(useMC));
2a1c7696 200 TVector3 momentumM(mother.Vect());
201 TVector3 normal(mother.Y() / momentumM.Mag(), -mother.X() / momentumM.Mag(), 0.0);
202
74d60285 203// // Computes first the invariant mass of the mother
204// Double_t mass0 = fDaughter[0]->P(useMC).M();
205// Double_t mass1 = fDaughter[1]->P(useMC).M();
206// Double_t p0 = daughter0.Vect().Mag();
207// Double_t p1 = daughter1.Vect().Mag();
208// Double_t E0 = TMath::Sqrt(mass0 * mass0 + p0 * p0);
209// Double_t E1 = TMath::Sqrt(mass1 * mass1 + p1 * p1);
210// Double_t MotherMass = TMath::Sqrt((E0 + E1) * (E0 + E1) - (p0 * p0 + 2.0 * daughter0.Vect().Dot(daughter1.Vect()) + p1 * p1));
211// MotherMass = fSum.M();
2a1c7696 212
213 // Computes components of beta
214 Double_t betaX = -mother.X() / mother.E();
215 Double_t betaY = -mother.Y() / mother.E();
216 Double_t betaZ = -mother.Z() / mother.E();
217
218 // Computes Lorentz transformation of the momentum of the first daughter
219 // into the rest frame of the mother and theta*
220 daughter0.Boost(betaX, betaY, betaZ);
221 TVector3 momentumD = daughter0.Vect();
222
223 Double_t cosThetaStar = normal.Dot(momentumD) / momentumD.Mag();
224
225 return cosThetaStar;
cadcd9e0 226}
227
f34f960b 228//__________________________________________________________________________________________________
2dab9030 229void AliRsnMother::PrintInfo(const Option_t * /*option*/) const
230{
231//
232// Print some info of the pair.
233// The options are passed to the AliRsnDaughter::Print() method
234//
235
2a1c7696 236 AliInfo("======== BEGIN PAIR INFO ===========");
237 AliInfo("Track #1");
238 fDaughter[0]->Print();
239 AliInfo("Track #2");
240 fDaughter[1]->Print();
241 AliInfo("========= END PAIR INFO ===========");
2dab9030 242}
243
f34f960b 244//__________________________________________________________________________________________________
0206329d 245Bool_t AliRsnMother::CheckPair(Bool_t checkMC) const
2dab9030 246{
247//
248// Checks that the pair is well initialized:
249// - both daughters are good pointers
250// - if MC is required, both daughters have a MC reference
251//
252
2a1c7696 253 if (!fDaughter[0] || !fDaughter[1]) {
254 AliError("One of the two tracks is NULL in this pair!");
2dab9030 255 return kFALSE;
2a1c7696 256 }
257
0206329d 258 if (checkMC) {
2a1c7696 259 if (fDaughter[0]->GetRefMC() == 0x0 || fDaughter[1]->GetRefMC() == 0x0) {
260 AliError("Required MC info but not all MC refs are available");
261 return kFALSE;
262 }
263 }
264
265 return kTRUE;
2dab9030 266}