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
44 virtual Double_t GetQtLCMS(); //returns Q transverse CMS longitudionally co-moving
46 virtual Double_t GetQt(); //returns Q transverse to Kt
49 virtual Double_t GetKt(); //returns K transverse
50 virtual Double_t GetKStar();
51 virtual Double_t GetKStarOut(); //z.ch.
52 virtual Double_t GetKStarSide(); //z.ch.
53 virtual Double_t GetKStarLong(); //z.ch.
56 virtual Double_t GetAvarageDistance();//returns avarage distnace between two tracks
58 virtual Double_t GetDeltaE(); //return difference of Energies
59 virtual Double_t GetDeltaP(); //return difference of momenta (scalar difference)
60 virtual Double_t GetDeltaPvector(); //return legth of difference vector of momenta
61 virtual Double_t GetDeltaPt();
62 virtual Double_t GetDeltaPx();
63 virtual Double_t GetDeltaPy();
64 virtual Double_t GetDeltaPz();
66 virtual Double_t GetDeltaTheta();
67 virtual Double_t GetDeltaPhi();
69 virtual Double_t GetGammaToLCMS();
70 virtual Double_t GetPIDProb() const {return fPart1->GetPidProb()*fPart2->GetPidProb();}
73 AliVAODParticle* fPart1; //pointer to first particle
74 AliVAODParticle* fPart2; //pointer to second particle
76 AliAODPair* fSwappedPair; //pointer to swapped pair
78 /************************************************************/
79 /************CMS (LC) Q's *********************************/
80 /************************************************************/
81 //Center Mass System - Longitudinally Comoving
83 Double_t fQSideLCMS; //value of Q side CMS longitudially co-moving
84 Bool_t fQSideLCMSNotCalc; //flag indicating if fQSideLCMS is already calculated for this pair
86 Double_t fQOutLCMS; //value of Q out CMS longitudially co-moving
87 Bool_t fQOutLCMSNotCalc;//flag indicating if fQOutLCMS is already calculated for this pair
89 Double_t fQLongLCMS; //value of Q long CMS longitudially co-moving
90 Bool_t fQLongLCMSNotCalc;//flag indicating if fQLongLCMS is already calculated for this pair
92 Double_t fQtLCMS; //value of Qt CMS longitudially co-moving (hypot(qsidelcms,qoutlcms))
93 Bool_t fQtLCMSNotCalc;//flag indicating if fQLongLCMS is already calculated for this pair
95 Double_t fQt; //value of Qt, projection of 3-mom diff to Kt
96 Bool_t fQtNotCalc;//flag indicating if fQt is already calculated for this pair
98 /************************************************************/
99 /************************************************************/
100 Double_t fQInv; //half of differnece of 4-momenta
101 Bool_t fQInvNotCalc;//flag indicating if fQInv is already calculated for this pair
103 Double_t fInvMass; //invariant mass
104 Bool_t fInvMassNotCalc;//flag indicating if fInvMass is already calculated for this pair
106 Double_t fKt; //K == sum vector of particle's momenta. Kt transverse component
107 Bool_t fKtNotCalc;//flag indicating if fKt is already calculated for this pair
109 Double_t fKStar; // KStar
110 Bool_t fKStarNotCalc;// flag indicating if fKStar is calculated
111 Double_t fKStarOut; // KStarOut z.ch.
112 Double_t fKStarSide;// KStarSide z.ch.
113 Double_t fKStarLong;// KStarLong z.ch.
115 Bool_t fKStarCompNotCalc; // flag indicating if CalcuteKStarComp() is calculated z.ch.
117 Double_t fPInv; //invariant momentum
119 Double_t fQSide; //Q Side
120 Double_t fOut;//Q Out
121 Double_t fQLong;//Q Long
123 Double_t fMt;//Transverse coordinate of Inv. Mass
124 Bool_t fMtNotCalc;//flag indicating if Mt is calculated for current pair
126 Double_t fInvMassSqr;//squre of invariant mass
127 Bool_t fMassSqrNotCalc; //flag indicating if fInvMassSqr for this pair
128 void CalculateInvMassSqr();
130 Double_t fQInvL; //Qinv in longitudional direction
131 Bool_t fQInvLNotCalc;//flag indicating if fQInvL is calculated for current pair
132 void CalculateQInvL();
134 Double_t fAvarageDistance;//value of the avarage distance calculated out of track points
135 Bool_t fAvarageDistanceNotCalc;//flag indicating if the avarage distance is calculated
137 Double_t fPxSum;// Sum of Px momenta
138 Double_t fPySum;// Sum of Py momenta
139 Double_t fPzSum;// Sum of Pz momenta
140 Double_t fESum;// Sum of energies
141 Bool_t fSumsNotCalc;//flag indicating if fPxSum,fPxSum,fPxSum and fESum is calculated for current pair
142 void CalculateSums();
143 void CalculateKStarComp();
145 Double_t fPxDiff;// Difference of Px momenta
146 Double_t fPyDiff;// Difference of Px momenta
147 Double_t fPzDiff;// Difference of Px momenta
148 Double_t fEDiff;// Difference of Px momenta
149 Bool_t fDiffsNotCalc;//flag indicating if fPxDiff,fPxDiff,fPxDiff and fEDiff is calculated for current pair
150 void CalculateDiffs();
152 Double_t fGammaLCMS;//gamma of boost in LCMS
153 Bool_t fGammaLCMSNotCalc;//flag indicating if fGammaLCMS is calculated for current pair
154 /***************************************************/
155 Bool_t fChanged;//flag indicating if object has been changed
157 void CalculateBase();
158 Double_t AvDistance();
162 ClassDef(AliAODPair,1)
164 /****************************************************************/
166 void AliAODPair::SetParticles(AliVAODParticle* p1,AliVAODParticle* p2)
168 //sets the particle to the pair
172 if (fSwappedPair) //if we have Swapped (so we are not)
173 fSwappedPair->SetParticles(p2,p1); //set particles for him too
175 //and do nothing until will be asked for
177 /****************************************************************/
180 void AliAODPair::Changed()
182 // Resel all calculations (flags)
184 fSumsNotCalc = kTRUE;
185 fDiffsNotCalc = kTRUE;
186 fMassSqrNotCalc = kTRUE;
187 fInvMassNotCalc = kTRUE;
188 fQInvNotCalc = kTRUE;
190 fQSideLCMSNotCalc = kTRUE;
191 fQOutLCMSNotCalc = kTRUE;
192 fQLongLCMSNotCalc = kTRUE;
193 fQtLCMSNotCalc = kTRUE;
196 fKStarNotCalc = kTRUE;
197 fKStarCompNotCalc = kTRUE;
198 fQInvLNotCalc = kTRUE;
199 fGammaLCMSNotCalc = kTRUE;
200 fAvarageDistanceNotCalc = kTRUE;
202 /****************************************************************/
204 void AliAODPair::CalculateInvMassSqr()
206 //calculates square of qinv
211 Double_t fPart12s= (fPxSum*fPxSum) + (fPySum*fPySum) + (fPzSum*fPzSum);
213 fInvMassSqr=fESum*fESum-fPart12s;
215 fMassSqrNotCalc = kFALSE;
218 /****************************************************************/
220 void AliAODPair::CalculateQInvL()
222 //Calculates square root of Qinv
226 fQInvL = fEDiff*fEDiff - ( fPxDiff*fPxDiff + fPyDiff*fPyDiff + fPzDiff*fPzDiff );
227 fQInvLNotCalc = kFALSE;
230 /****************************************************************/
232 void AliAODPair::CalculateSums()
234 //calculates momenta and energy sums
237 fPxSum = fPart1->Px()+fPart2->Px();
238 fPySum = fPart1->Py()+fPart2->Py();
239 fPzSum = fPart1->Pz()+fPart2->Pz();
240 fESum = fPart1->E() + fPart2->E();
241 fSumsNotCalc = kFALSE;
244 /****************************************************************/
246 void AliAODPair::CalculateKStarComp()
249 if (fKStarCompNotCalc)
253 Double_t ptrans = fPxSum*fPxSum + fPySum*fPySum;
254 Double_t mtrans = fESum*fESum - fPzSum*fPzSum;
255 Double_t pinv = TMath::Sqrt(mtrans - ptrans);
256 ptrans = TMath::Sqrt(ptrans);
257 mtrans = TMath::Sqrt(mtrans);
259 Double_t px1 = fPart1->Px();
260 Double_t py1 = fPart1->Py();
261 Double_t pz1 = fPart1->Pz();
262 Double_t pE1 = fPart1->E();
265 Double_t beta = fPzSum / fESum;
266 Double_t gamma = fESum / mtrans;
268 fKStarLong = gamma * (pz1 - beta * pE1);
269 double temp = gamma * (pE1 - beta * pz1);
271 // rotate in transverse plane
272 fKStarSide = (-px1*fPySum + py1*fPxSum)/ptrans;
273 fKStarOut = ( px1*fPxSum + py1*fPySum)/ptrans;
275 // go from LCMS to CMS
277 beta = ptrans/mtrans;
278 fKStarOut = gamma * (fKStarOut - beta * temp);
280 fKStarCompNotCalc = kFALSE;
284 /****************************************************************/
286 void AliAODPair::CalculateDiffs()
288 //calculates momenta and energy differences
291 fPxDiff = fPart1->Px()-fPart2->Px();
292 fPyDiff = fPart1->Py()-fPart2->Py();
293 fPzDiff = fPart1->Pz()-fPart2->Pz();
294 fEDiff = fPart1->E() - fPart2->E();
295 fDiffsNotCalc = kFALSE;
299 /****************************************************************/
302 Double_t AliAODPair::GetDeltaE()
304 //returns difference of energies
305 return fPart1->E() - fPart2->E();
307 /****************************************************************/
310 Double_t AliAODPair::GetDeltaP()
312 //returns difference of momenta (scalars)
313 return fPart1->P() - fPart2->P();
315 /****************************************************************/
318 Double_t AliAODPair::GetDeltaPvector() //return difference of momenta
320 //returns legth of the momenta difference vector
322 return TMath::Sqrt(fPxDiff*fPxDiff + fPyDiff*fPyDiff + fPzDiff*fPzDiff);
324 /****************************************************************/
327 Double_t AliAODPair::GetDeltaPt()
329 //returns difference of Pz
330 return fPart1->Pt()-fPart2->Pt();
332 /****************************************************************/
335 Double_t AliAODPair::GetDeltaPx()
337 //returns difference of Pz
341 /****************************************************************/
343 Double_t AliAODPair::GetDeltaPy()
345 //returns difference of Py
350 /****************************************************************/
352 Double_t AliAODPair::GetDeltaPz()
354 //returns difference of Pz
358 /****************************************************************/
361 Double_t AliAODPair::GetDeltaPhi()
363 //returns difference of Phi
364 Double_t phi1 = fPart1->Phi();
365 Double_t phi2 = fPart2->Phi();
366 Double_t diff = phi1-phi2;
367 if (TMath::Abs(diff) > TMath::Pi())
369 if (phi1 > TMath::Pi())
371 phi1-=TMath::TwoPi();
375 phi2-=TMath::TwoPi();
381 /****************************************************************/
384 Double_t AliAODPair::GetDeltaTheta()
386 //returns difference of Theta
387 return fPart1->Theta()-fPart2->Theta();
389 /****************************************************************/