1 /**************************************************************************
2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
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 **************************************************************************/
16 ////////////////////////////////////////////////////////////////////////////////
18 // This class contains all code which is used to compute any of the values
19 // which can be of interest within a resonance analysis. Besides the obvious
20 // invariant mass, it allows to compute other utility values on all possible
21 // targets, in order to allow a wide spectrum of binning and checks.
22 // When needed, this object can also define a binning in the variable which
23 // it is required to compute, which is used for initializing axes of output
24 // histograms (see AliRsnFunction).
25 // The value computation requires this object to be passed the object whose
26 // informations will be used. This object can be of any allowed input type
27 // (track, pair, event), then this class must inherit from AliRsnTarget.
28 // Then, when value computation is attempted, a check on target type is done
29 // and computation is successful only if expected target matches that of the
31 // In some cases, the value computation can require a support external object,
32 // which must then be passed to this class. It can be of any type inheriting
35 // authors: A. Pulvirenti (alberto.pulvirenti@ct.infn.it)
36 // M. Vala (martin.vala@cern.ch)
38 ////////////////////////////////////////////////////////////////////////////////
40 #include "Riostream.h"
41 #include "AliVVertex.h"
42 #include "AliMultiplicity.h"
43 #include "AliESDtrackCuts.h"
44 #include "AliESDpid.h"
45 #include "AliAODPid.h"
46 #include "AliCentrality.h"
47 #include "AliESDUtils.h"
49 #include "AliRsnEvent.h"
50 #include "AliRsnDaughter.h"
51 #include "AliRsnMother.h"
52 #include "AliRsnPairDef.h"
53 #include "AliRsnDaughterDef.h"
55 #include "AliRsnValuePair.h"
57 ClassImp(AliRsnValuePair)
59 //_____________________________________________________________________________
60 AliRsnValuePair::AliRsnValuePair(const char *name, EType type) :
61 AliRsnValue(name, AliRsnTarget::kMother),
69 //_____________________________________________________________________________
70 AliRsnValuePair::AliRsnValuePair(const AliRsnValuePair& copy) :
79 //_____________________________________________________________________________
80 AliRsnValuePair& AliRsnValuePair::operator=(const AliRsnValuePair& copy)
83 // Assignment operator.
84 // Works like copy constructor.
87 AliRsnValue::operator=(copy);
93 //_____________________________________________________________________________
94 const char* AliRsnValuePair::GetTypeName() const
97 // This method returns a string to give a name to each possible
102 case kPt: return "PairPt";
103 case kPz: return "PairPz";
104 case kInvMass: return "PairInvMass";
105 case kInvMassRes: return "PairInvMassResolution";
106 case kEta: return "PairEta";
107 case kMt: return "PairMt";
108 case kY: return "PairY";
109 case kPtRatio: return "PairPtRatio";
110 case kDipAngle: return "PairDipAngle";
111 case kCosThetaStar: return "PairCosThetaStar";
112 case kAngleLeading: return "PairAngleToLeading";
113 default: return "Undefined";
117 //_____________________________________________________________________________
118 Bool_t AliRsnValuePair::Eval(TObject *object)
121 // Evaluation of the required value.
122 // In this implementation, fills the member 4-vectors with data
123 // coming from the object passed as argument, and then returns the value
126 // coherence check, which also casts object
127 // to AliRsnTarget data members and returns kFALSE
128 // in case the object is NULL
129 if (!TargetOK(object)) return kFALSE;
131 // set a reference to the mother momentum
132 TLorentzVector &sum = fMother->Sum(fUseMCInfo);
133 TLorentzVector &ref = fMother->Ref(fUseMCInfo);
134 TLorentzVector &p1 = fMother->GetDaughter(0)->P(fUseMCInfo);
135 TLorentzVector &p2 = fMother->GetDaughter(1)->P(fUseMCInfo);
140 // compute value depending on types in the enumeration
141 // if the type does not match any available choice, or if
142 // the computation is not doable due to any problem
143 // (not initialized support object, wrong values, risk of floating point errors)
144 // the method returng kFALSE and sets the computed value to a meaningless number
147 fComputedValue = sum.Perp();
150 fComputedValue = sum.M();
153 fComputedValue = sum.Eta();
156 fComputedValue = fMother->Sum(kFALSE).M() - fMother->Sum(kTRUE).M();
157 fComputedValue /= fMother->Sum(kTRUE).M();
160 fComputedValue = ref.Mt();
163 fComputedValue = ref.Rapidity();
166 fComputedValue = TMath::Abs(p1.Perp() - p2.Perp());
167 fComputedValue /= TMath::Abs(p1.Perp() + p2.Perp());
170 fComputedValue = p1.Perp() * p2.Perp() + p1.Z() * p2.Z();
171 fComputedValue /= p1.Mag() * p2.Mag();
174 fComputedValue = fMother->CosThetaStar();
177 fComputedValue = fMother->AngleToLeading(success);
180 AliError(Form("[%s] Invalid value type for this computation", GetName()));