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();}
72 virtual Double_t GetRStar() ;
73 virtual Double_t GetR() ;//returns distance between particle production points
78 AliVAODParticle* fPart1; //pointer to first particle
79 AliVAODParticle* fPart2; //pointer to second particle
81 AliAODPair* fSwappedPair; //pointer to swapped pair
83 /************************************************************/
84 /************CMS (LC) Q's *********************************/
85 /************************************************************/
86 //Center Mass System - Longitudinally Comoving
88 Double_t fQSideLCMS; //value of Q side CMS longitudially co-moving
89 Bool_t fQSideLCMSNotCalc; //flag indicating if fQSideLCMS is already calculated for this pair
91 Double_t fQOutLCMS; //value of Q out CMS longitudially co-moving
92 Bool_t fQOutLCMSNotCalc;//flag indicating if fQOutLCMS is already calculated for this pair
94 Double_t fQLongLCMS; //value of Q long CMS longitudially co-moving
95 Bool_t fQLongLCMSNotCalc;//flag indicating if fQLongLCMS is already calculated for this pair
97 Double_t fQtLCMS; //value of Qt CMS longitudially co-moving (hypot(qsidelcms,qoutlcms))
98 Bool_t fQtLCMSNotCalc;//flag indicating if fQLongLCMS is already calculated for this pair
100 Double_t fQt; //value of Qt, projection of 3-mom diff to Kt
101 Bool_t fQtNotCalc;//flag indicating if fQt is already calculated for this pair
103 /************************************************************/
104 /************************************************************/
105 Double_t fQInv; //half of differnece of 4-momenta
106 Bool_t fQInvNotCalc;//flag indicating if fQInv is already calculated for this pair
108 Double_t fInvMass; //invariant mass
109 Bool_t fInvMassNotCalc;//flag indicating if fInvMass is already calculated for this pair
111 Double_t fKt; //K == sum vector of particle's momenta. Kt transverse component
112 Bool_t fKtNotCalc;//flag indicating if fKt is already calculated for this pair
114 Double_t fKStar; // KStar
115 Bool_t fKStarNotCalc;// flag indicating if fKStar is calculated
116 Double_t fKStarOut; // KStarOut z.ch.
117 Double_t fKStarSide;// KStarSide z.ch.
118 Double_t fKStarLong;// KStarLong z.ch.
120 Bool_t fKStarCompNotCalc; // flag indicating if CalcuteKStarComp() is calculated z.ch.
122 Double_t fPInv; //invariant momentum
124 Double_t fQSide; //Q Side
125 Double_t fOut;//Q Out
126 Double_t fQLong;//Q Long
128 Double_t fMt;//Transverse coordinate of Inv. Mass
129 Bool_t fMtNotCalc;//flag indicating if Mt is calculated for current pair
131 Double_t fInvMassSqr;//squre of invariant mass
132 Bool_t fMassSqrNotCalc; //flag indicating if fInvMassSqr for this pair
133 void CalculateInvMassSqr();
135 Double_t fQInvL; //Qinv in longitudional direction
136 Bool_t fQInvLNotCalc;//flag indicating if fQInvL is calculated for current pair
137 void CalculateQInvL();
139 Double_t fAvarageDistance;//value of the avarage distance calculated out of track points
140 Bool_t fAvarageDistanceNotCalc;//flag indicating if the avarage distance is calculated
142 Double_t fPxSum;// Sum of Px momenta
143 Double_t fPySum;// Sum of Py momenta
144 Double_t fPzSum;// Sum of Pz momenta
145 Double_t fESum;// Sum of energies
146 Bool_t fSumsNotCalc;//flag indicating if fPxSum,fPxSum,fPxSum and fESum is calculated for current pair
147 void CalculateSums();
148 void CalculateKStarComp();
150 Double_t fPxDiff;// Difference of Px momenta
151 Double_t fPyDiff;// Difference of Px momenta
152 Double_t fPzDiff;// Difference of Px momenta
153 Double_t fEDiff;// Difference of Px momenta
154 Bool_t fDiffsNotCalc;//flag indicating if fPxDiff,fPxDiff,fPxDiff and fEDiff is calculated for current pair
155 void CalculateDiffs();
157 Double_t fGammaLCMS;//gamma of boost in LCMS
158 Bool_t fGammaLCMSNotCalc;//flag indicating if fGammaLCMS is calculated for current pair
159 /***************************************************/
160 Bool_t fChanged;//flag indicating if object has been changed
162 void CalculateBase();
163 Double_t AvDistance();
167 ClassDef(AliAODPair,1)
169 /****************************************************************/
171 void AliAODPair::SetParticles(AliVAODParticle* p1,AliVAODParticle* p2)
173 //sets the particle to the pair
177 if (fSwappedPair) //if we have Swapped (so we are not)
178 fSwappedPair->SetParticles(fPart2,p1); //set particles for him too
180 //and do nothing until will be asked for
182 /****************************************************************/
185 void AliAODPair::Changed()
187 // Resel all calculations (flags)
189 fSumsNotCalc = kTRUE;
190 fDiffsNotCalc = kTRUE;
191 fMassSqrNotCalc = kTRUE;
192 fInvMassNotCalc = kTRUE;
193 fQInvNotCalc = kTRUE;
195 fQSideLCMSNotCalc = kTRUE;
196 fQOutLCMSNotCalc = kTRUE;
197 fQLongLCMSNotCalc = kTRUE;
198 fQtLCMSNotCalc = kTRUE;
201 fKStarNotCalc = kTRUE;
202 fKStarCompNotCalc = kTRUE;
203 fQInvLNotCalc = kTRUE;
204 fGammaLCMSNotCalc = kTRUE;
205 fAvarageDistanceNotCalc = kTRUE;
207 /****************************************************************/
209 void AliAODPair::CalculateInvMassSqr()
211 //calculates square of qinv
216 Double_t fPart12s= (fPxSum*fPxSum) + (fPySum*fPySum) + (fPzSum*fPzSum);
218 fInvMassSqr=fESum*fESum-fPart12s;
220 fMassSqrNotCalc = kFALSE;
223 /****************************************************************/
225 void AliAODPair::CalculateQInvL()
227 //Calculates square root of Qinv
231 fQInvL = fEDiff*fEDiff - ( fPxDiff*fPxDiff + fPyDiff*fPyDiff + fPzDiff*fPzDiff );
232 fQInvLNotCalc = kFALSE;
235 /****************************************************************/
237 void AliAODPair::CalculateSums()
239 //calculates momenta and energy sums
242 fPxSum = fPart1->Px()+fPart2->Px();
243 fPySum = fPart1->Py()+fPart2->Py();
244 fPzSum = fPart1->Pz()+fPart2->Pz();
245 fESum = fPart1->E() + fPart2->E();
246 fSumsNotCalc = kFALSE;
249 /****************************************************************/
251 void AliAODPair::CalculateKStarComp()
254 if (fKStarCompNotCalc)
258 Double_t ptrans = fPxSum*fPxSum + fPySum*fPySum;
259 Double_t mtrans = fESum*fESum - fPzSum*fPzSum;
260 Double_t pinv = TMath::Sqrt(mtrans - ptrans);
261 ptrans = TMath::Sqrt(ptrans);
262 mtrans = TMath::Sqrt(mtrans);
264 Double_t px1 = fPart1->Px();
265 Double_t py1 = fPart1->Py();
266 Double_t pz1 = fPart1->Pz();
267 Double_t pE1 = fPart1->E();
270 Double_t beta = fPzSum / fESum;
271 Double_t gamma = fESum / mtrans;
273 fKStarLong = gamma * (pz1 - beta * pE1);
274 double temp = gamma * (pE1 - beta * pz1);
276 // rotate in transverse plane
277 fKStarSide = (-px1*fPySum + py1*fPxSum)/ptrans;
278 fKStarOut = ( px1*fPxSum + py1*fPySum)/ptrans;
280 // go from LCMS to CMS
282 beta = ptrans/mtrans;
283 fKStarOut = gamma * (fKStarOut - beta * temp);
285 fKStarCompNotCalc = kFALSE;
289 /****************************************************************/
291 void AliAODPair::CalculateDiffs()
293 //calculates momenta and energy differences
296 fPxDiff = fPart1->Px()-fPart2->Px();
297 fPyDiff = fPart1->Py()-fPart2->Py();
298 fPzDiff = fPart1->Pz()-fPart2->Pz();
299 fEDiff = fPart1->E() - fPart2->E();
300 fDiffsNotCalc = kFALSE;
304 /****************************************************************/
307 Double_t AliAODPair::GetDeltaE()
309 //returns difference of energies
310 return fPart1->E() - fPart2->E();
312 /****************************************************************/
315 Double_t AliAODPair::GetDeltaP()
317 //returns difference of momenta (scalars)
318 return fPart1->P() - fPart2->P();
320 /****************************************************************/
323 Double_t AliAODPair::GetDeltaPvector() //return difference of momenta
325 //returns legth of the momenta difference vector
327 return TMath::Sqrt(fPxDiff*fPxDiff + fPyDiff*fPyDiff + fPzDiff*fPzDiff);
329 /****************************************************************/
332 Double_t AliAODPair::GetDeltaPt()
334 //returns difference of Pz
335 return fPart1->Pt()-fPart2->Pt();
337 /****************************************************************/
340 Double_t AliAODPair::GetDeltaPx()
342 //returns difference of Pz
346 /****************************************************************/
348 Double_t AliAODPair::GetDeltaPy()
350 //returns difference of Py
355 /****************************************************************/
357 Double_t AliAODPair::GetDeltaPz()
359 //returns difference of Pz
363 /****************************************************************/
366 Double_t AliAODPair::GetDeltaPhi()
368 //returns difference of Phi
369 Double_t phi1 = fPart1->Phi();
370 Double_t phi2 = fPart2->Phi();
371 Double_t diff = phi1-phi2;
372 if (TMath::Abs(diff) > TMath::Pi())
374 if (phi1 > TMath::Pi())
376 phi1-=TMath::TwoPi();
380 phi2-=TMath::TwoPi();
386 /****************************************************************/
389 Double_t AliAODPair::GetDeltaTheta()
391 //returns difference of Theta
392 return fPart1->Theta()-fPart2->Theta();
394 /****************************************************************/