3 //_________________________________________________________________________
4 ///////////////////////////////////////////////////////////////////////////
8 // class implements pair of particles and taking care of caluclation (almost)
9 // all of pair properties (Qinv, InvMass,...)
10 // more info: http://alisoft.cern.ch/people/skowron/analyzer/index.html
12 ////////////////////////////////////////////////////////////////////////////
15 #include "AliVAODParticle.h"
18 class AliAODPair: public TObject
21 AliAODPair(Bool_t rev = kFALSE); //contructor
22 AliAODPair(AliVAODParticle* part1, AliVAODParticle* part2, Bool_t rev = kFALSE); //contructor
23 AliAODPair(const AliAODPair& in);
25 virtual ~AliAODPair(){}
27 AliAODPair& operator=(const AliAODPair& in);
29 void SetParticles(AliVAODParticle* p1,AliVAODParticle* p2); //sets particles in the pair
30 AliAODPair* GetSwappedPair() {return fSwappedPair;} //returns pair with swapped particles
32 AliVAODParticle* Particle1() const {return fPart1;} //returns pointer to first particle
33 AliVAODParticle* Particle2() const {return fPart2;} //returns pointer to decond particle
35 virtual void Changed();
36 //Center Mass System - Longitudinally Comoving
38 virtual Double_t GetInvMass(); //returns invariant mass of the pair
39 virtual Double_t GetMt();
40 virtual Double_t GetQInv(); //returns Q invariant
41 virtual Double_t GetQSideLCMS(); //returns Q Side CMS longitudionally co-moving
42 virtual Double_t GetQOutLCMS(); //returns Q out CMS longitudionally co-moving
43 virtual Double_t GetQLongLCMS(); //returns Q Long CMS longitudionally co-moving
46 virtual Double_t GetKt(); //returns K transverse
47 virtual Double_t GetKStar();
49 virtual Double_t GetAvarageDistance();//returns avarage distnace between two tracks
51 virtual Double_t GetDeltaP(); //return difference of momenta
52 virtual Double_t GetDeltaPt();
53 virtual Double_t GetDeltaPx();
54 virtual Double_t GetDeltaPy();
55 virtual Double_t GetDeltaPz();
57 virtual Double_t GetDeltaTheta();
58 virtual Double_t GetDeltaPhi();
60 virtual Double_t GetGammaToLCMS();
61 virtual Double_t GetPIDProb() const {return fPart1->GetPidProb()*fPart2->GetPidProb();}
64 AliVAODParticle* fPart1; //pointer to first particle
65 AliVAODParticle* fPart2; //pointer to second particle
67 AliAODPair* fSwappedPair; //pointer to swapped pair
69 /************************************************************/
70 /************CMS (LC) Q's *********************************/
71 /************************************************************/
72 //Center Mass System - Longitudinally Comoving
74 Double_t fQSideLCMS; //value of Q side CMS longitudially co-moving
75 Bool_t fQSideLCMSNotCalc; //flag indicating if fQSideLCMS is already calculated for this pair
77 Double_t fQOutLCMS; //value of Q out CMS longitudially co-moving
78 Bool_t fQOutLCMSNotCalc;//flag indicating if fQOutLCMS is already calculated for this pair
80 Double_t fQLongLCMS; //value of Q long CMS longitudially co-moving
81 Bool_t fQLongLCMSNotCalc;//flag indicating if fQLongLCMS is already calculated for this pair
82 /************************************************************/
83 /************************************************************/
84 Double_t fQInv; //half of differnece of 4-momenta
85 Bool_t fQInvNotCalc;//flag indicating if fQInv is already calculated for this pair
87 Double_t fInvMass; //invariant mass
88 Bool_t fInvMassNotCalc;//flag indicating if fInvMass is already calculated for this pair
90 Double_t fKt; //K == sum vector of particle's momenta. Kt transverse component
91 Bool_t fKtNotCalc;//flag indicating if fKt is already calculated for this pair
93 Double_t fKStar; // KStar
94 Bool_t fKStarNotCalc;// flag indicating if fKStar is calculated
96 Double_t fPInv; //invariant momentum
98 Double_t fQSide; //Q Side
100 Double_t fQLong;//Q Long
102 Double_t fMt;//Transverse coordinate of Inv. Mass
103 Bool_t fMtNotCalc;//flag indicating if Mt is calculated for current pair
105 Double_t fInvMassSqr;//squre of invariant mass
106 Bool_t fMassSqrNotCalc; //flag indicating if fInvMassSqr for this pair
107 void CalculateInvMassSqr();
109 Double_t fQInvL; //Qinv in longitudional direction
110 Bool_t fQInvLNotCalc;//flag indicating if fQInvL is calculated for current pair
111 void CalculateQInvL();
113 Double_t fAvarageDistance;//value of the avarage distance calculated out of track points
114 Bool_t fAvarageDistanceNotCalc;//flag indicating if the avarage distance is calculated
116 Double_t fPxSum;// Sum of Px momenta
117 Double_t fPySum;// Sum of Py momenta
118 Double_t fPzSum;// Sum of Pz momenta
119 Double_t fESum;// Sum of energies
120 Bool_t fSumsNotCalc;//flag indicating if fPxSum,fPxSum,fPxSum and fESum is calculated for current pair
121 void CalculateSums();
123 Double_t fPxDiff;// Difference of Px momenta
124 Double_t fPyDiff;// Difference of Px momenta
125 Double_t fPzDiff;// Difference of Px momenta
126 Double_t fEDiff;// Difference of Px momenta
127 Bool_t fDiffsNotCalc;//flag indicating if fPxDiff,fPxDiff,fPxDiff and fEDiff is calculated for current pair
128 void CalculateDiffs();
130 Double_t fGammaLCMS;//gamma of boost in LCMS
131 Bool_t fGammaLCMSNotCalc;//flag indicating if fGammaLCMS is calculated for current pair
132 /***************************************************/
133 Bool_t fChanged;//flag indicating if object has been changed
135 void CalculateBase();
136 Double_t AvDistance();
140 ClassDef(AliAODPair,1)
142 /****************************************************************/
144 void AliAODPair::SetParticles(AliVAODParticle* p1,AliVAODParticle* p2)
146 //sets the particle to the pair
150 if (fSwappedPair) //if we have Swapped (so we are not)
151 fSwappedPair->SetParticles(p2,p1); //set particles for him too
153 //and do nothing until will be asked for
155 /****************************************************************/
158 void AliAODPair::Changed()
160 // Resel all calculations (flags)
162 fSumsNotCalc = kTRUE;
163 fDiffsNotCalc = kTRUE;
164 fMassSqrNotCalc = kTRUE;
165 fInvMassNotCalc = kTRUE;
166 fQInvNotCalc = kTRUE;
168 fQSideLCMSNotCalc = kTRUE;
169 fQOutLCMSNotCalc = kTRUE;
170 fQLongLCMSNotCalc = kTRUE;
172 fKStarNotCalc = kTRUE;
173 fQInvLNotCalc = kTRUE;
174 fGammaLCMSNotCalc = kTRUE;
175 fAvarageDistanceNotCalc = kTRUE;
177 /****************************************************************/
179 void AliAODPair::CalculateInvMassSqr()
181 //calculates square of qinv
186 Double_t fPart12s= (fPxSum*fPxSum) + (fPySum*fPySum) + (fPzSum*fPzSum);
188 fInvMassSqr=fESum*fESum-fPart12s;
190 fMassSqrNotCalc = kFALSE;
193 /****************************************************************/
195 void AliAODPair::CalculateQInvL()
197 //Calculates square root of Qinv
201 fQInvL = fEDiff*fEDiff - ( fPxDiff*fPxDiff + fPyDiff*fPyDiff + fPzDiff*fPzDiff );
202 fQInvLNotCalc = kFALSE;
205 /****************************************************************/
207 void AliAODPair::CalculateSums()
209 //calculates momenta and energy sums
212 fPxSum = fPart1->Px()+fPart2->Px();
213 fPySum = fPart1->Py()+fPart2->Py();
214 fPzSum = fPart1->Pz()+fPart2->Pz();
215 fESum = fPart1->E() + fPart2->E();
216 fSumsNotCalc = kFALSE;
219 /****************************************************************/
221 void AliAODPair::CalculateDiffs()
223 //calculates momenta and energy differences
226 fPxDiff = fPart1->Px()-fPart2->Px();
227 fPyDiff = fPart1->Py()-fPart2->Py();
228 fPzDiff = fPart1->Pz()-fPart2->Pz();
229 fEDiff = fPart1->E() - fPart2->E();
230 fDiffsNotCalc = kFALSE;
234 /****************************************************************/
236 Double_t AliAODPair::GetDeltaP() //return difference of momenta
238 //returns difference of momenta (length of vector)
240 return TMath::Sqrt(fPxDiff*fPxDiff + fPyDiff*fPyDiff + fPzDiff*fPzDiff);
242 /****************************************************************/
245 Double_t AliAODPair::GetDeltaPt()
247 //returns difference of Pz
248 return fPart1->Pt()-fPart2->Pt();
250 /****************************************************************/
253 Double_t AliAODPair::GetDeltaPx()
255 //returns difference of Pz
259 /****************************************************************/
261 Double_t AliAODPair::GetDeltaPy()
263 //returns difference of Py
268 /****************************************************************/
270 Double_t AliAODPair::GetDeltaPz()
272 //returns difference of Pz
276 /****************************************************************/
279 Double_t AliAODPair::GetDeltaPhi()
281 //returns difference of Phi
282 Double_t phi1 = fPart1->Phi();
283 Double_t phi2 = fPart2->Phi();
284 Double_t diff = phi1-phi2;
285 if (TMath::Abs(diff) > TMath::Pi())
287 if (phi1 > TMath::Pi())
289 phi1-=TMath::TwoPi();
293 phi2-=TMath::TwoPi();
299 /****************************************************************/
302 Double_t AliAODPair::GetDeltaTheta()
304 //returns difference of Theta
305 return fPart1->Theta()-fPart2->Theta();
307 /****************************************************************/