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 GetGammaToTransverse();
71 virtual Double_t GetPIDProb() const {return fPart1->GetPidProb()*fPart2->GetPidProb();}
73 virtual Double_t GetRStar() ;
74 virtual Double_t GetR() ;//returns distance between particle production points
79 void Print(const Option_t* option ) const {TObject::Print(option);}
83 AliVAODParticle* fPart1; //pointer to first particle
84 AliVAODParticle* fPart2; //pointer to second particle
86 AliAODPair* fSwappedPair; //pointer to swapped pair
88 /************************************************************/
89 /************CMS (LC) Q's *********************************/
90 /************************************************************/
91 //Center Mass System - Longitudinally Comoving
93 Double_t fQSideLCMS; //value of Q side CMS longitudially co-moving
94 Bool_t fQSideLCMSNotCalc; //flag indicating if fQSideLCMS is already calculated for this pair
96 Double_t fQOutLCMS; //value of Q out CMS longitudially co-moving
97 Bool_t fQOutLCMSNotCalc;//flag indicating if fQOutLCMS is already calculated for this pair
99 Double_t fQLongLCMS; //value of Q long CMS longitudially co-moving
100 Bool_t fQLongLCMSNotCalc;//flag indicating if fQLongLCMS is already calculated for this pair
102 Double_t fQtLCMS; //value of Qt CMS longitudially co-moving (hypot(qsidelcms,qoutlcms))
103 Bool_t fQtLCMSNotCalc;//flag indicating if fQLongLCMS is already calculated for this pair
105 Double_t fQt; //value of Qt, projection of 3-mom diff to Kt
106 Bool_t fQtNotCalc;//flag indicating if fQt is already calculated for this pair
108 /************************************************************/
109 /************************************************************/
110 Double_t fQInv; //half of differnece of 4-momenta
111 Bool_t fQInvNotCalc;//flag indicating if fQInv is already calculated for this pair
113 Double_t fInvMass; //invariant mass
114 Bool_t fInvMassNotCalc;//flag indicating if fInvMass is already calculated for this pair
116 Double_t fKt; //K == sum vector of particle's momenta. Kt transverse component
117 Bool_t fKtNotCalc;//flag indicating if fKt is already calculated for this pair
119 Double_t fKStar; // KStar
120 Bool_t fKStarNotCalc;// flag indicating if fKStar is calculated
121 Double_t fKStarOut; // KStarOut z.ch.
122 Double_t fKStarSide;// KStarSide z.ch.
123 Double_t fKStarLong;// KStarLong z.ch.
125 Bool_t fKStarCompNotCalc; // flag indicating if CalcuteKStarComp() is calculated z.ch.
127 Double_t fPInv; //invariant momentum
129 Double_t fQSide; //Q Side
130 Double_t fOut;//Q Out
131 Double_t fQLong;//Q Long
133 Double_t fMt;//Transverse coordinate of Inv. Mass
134 Bool_t fMtNotCalc;//flag indicating if Mt is calculated for current pair
136 Double_t fInvMassSqr;//squre of invariant mass
137 Bool_t fMassSqrNotCalc; //flag indicating if fInvMassSqr for this pair
138 void CalculateInvMassSqr();
140 Double_t fQInvL; //Qinv in longitudional direction
141 Bool_t fQInvLNotCalc;//flag indicating if fQInvL is calculated for current pair
142 void CalculateQInvL();
144 Double_t fAvarageDistance;//value of the avarage distance calculated out of track points
145 Bool_t fAvarageDistanceNotCalc;//flag indicating if the avarage distance is calculated
147 Double_t fPxSum;// Sum of Px momenta
148 Double_t fPySum;// Sum of Py momenta
149 Double_t fPzSum;// Sum of Pz momenta
150 Double_t fESum;// Sum of energies
151 Bool_t fSumsNotCalc;//flag indicating if fPxSum,fPxSum,fPxSum and fESum is calculated for current pair
152 void CalculateSums();
153 void CalculateKStarComp();
155 Double_t fPxDiff;// Difference of Px momenta
156 Double_t fPyDiff;// Difference of Px momenta
157 Double_t fPzDiff;// Difference of Px momenta
158 Double_t fEDiff;// Difference of Px momenta
159 Bool_t fDiffsNotCalc;//flag indicating if fPxDiff,fPxDiff,fPxDiff and fEDiff is calculated for current pair
160 void CalculateDiffs();
162 Double_t fGammaLCMS;//gamma of boost in LCMS
163 Bool_t fGammaLCMSNotCalc;//flag indicating if fGammaLCMS is calculated for current pair
164 /***************************************************/
165 Bool_t fChanged;//flag indicating if object has been changed
167 void CalculateBase();
168 Double_t AvDistance();
172 ClassDef(AliAODPair,1)
174 /****************************************************************/
176 void AliAODPair::SetParticles(AliVAODParticle* p1,AliVAODParticle* p2)
178 //sets the particle to the pair
182 if (fSwappedPair) //if we have Swapped (so we are not)
183 fSwappedPair->SetParticles(fPart2,p1); //set particles for him too
185 //and do nothing until will be asked for
187 /****************************************************************/
190 void AliAODPair::Changed()
192 // Resel all calculations (flags)
194 fSumsNotCalc = kTRUE;
195 fDiffsNotCalc = kTRUE;
196 fMassSqrNotCalc = kTRUE;
197 fInvMassNotCalc = kTRUE;
198 fQInvNotCalc = kTRUE;
200 fQSideLCMSNotCalc = kTRUE;
201 fQOutLCMSNotCalc = kTRUE;
202 fQLongLCMSNotCalc = kTRUE;
203 fQtLCMSNotCalc = kTRUE;
206 fKStarNotCalc = kTRUE;
207 fKStarCompNotCalc = kTRUE;
208 fQInvLNotCalc = kTRUE;
209 fGammaLCMSNotCalc = kTRUE;
210 fAvarageDistanceNotCalc = kTRUE;
212 /****************************************************************/
214 void AliAODPair::CalculateInvMassSqr()
216 //calculates square of qinv
221 Double_t fPart12s= (fPxSum*fPxSum) + (fPySum*fPySum) + (fPzSum*fPzSum);
223 fInvMassSqr=fESum*fESum-fPart12s;
225 fMassSqrNotCalc = kFALSE;
228 /****************************************************************/
230 void AliAODPair::CalculateQInvL()
232 //Calculates square root of Qinv
236 fQInvL = fEDiff*fEDiff - ( fPxDiff*fPxDiff + fPyDiff*fPyDiff + fPzDiff*fPzDiff );
237 fQInvLNotCalc = kFALSE;
240 /****************************************************************/
242 void AliAODPair::CalculateSums()
244 //calculates momenta and energy sums
247 fPxSum = fPart1->Px()+fPart2->Px();
248 fPySum = fPart1->Py()+fPart2->Py();
249 fPzSum = fPart1->Pz()+fPart2->Pz();
250 fESum = fPart1->E() + fPart2->E();
251 fSumsNotCalc = kFALSE;
254 /****************************************************************/
256 void AliAODPair::CalculateKStarComp()
259 if (fKStarCompNotCalc)
263 Double_t ptrans = fPxSum*fPxSum + fPySum*fPySum;
264 Double_t mtrans = fESum*fESum - fPzSum*fPzSum;
265 Double_t pinv = TMath::Sqrt(mtrans - ptrans);
266 ptrans = TMath::Sqrt(ptrans);
267 mtrans = TMath::Sqrt(mtrans);
269 Double_t px1 = fPart1->Px();
270 Double_t py1 = fPart1->Py();
271 Double_t pz1 = fPart1->Pz();
272 Double_t pE1 = fPart1->E();
275 Double_t beta = fPzSum / fESum;
276 Double_t gamma = fESum / mtrans;
278 fKStarLong = gamma * (pz1 - beta * pE1);
279 double temp = gamma * (pE1 - beta * pz1);
281 // rotate in transverse plane
282 fKStarSide = (-px1*fPySum + py1*fPxSum)/ptrans;
283 fKStarOut = ( px1*fPxSum + py1*fPySum)/ptrans;
285 // go from LCMS to CMS
287 beta = ptrans/mtrans;
288 fKStarOut = gamma * (fKStarOut - beta * temp);
290 fKStarCompNotCalc = kFALSE;
294 /****************************************************************/
296 void AliAODPair::CalculateDiffs()
298 //calculates momenta and energy differences
301 fPxDiff = fPart1->Px()-fPart2->Px();
302 fPyDiff = fPart1->Py()-fPart2->Py();
303 fPzDiff = fPart1->Pz()-fPart2->Pz();
304 fEDiff = fPart1->E() - fPart2->E();
305 fDiffsNotCalc = kFALSE;
309 /****************************************************************/
312 Double_t AliAODPair::GetDeltaE()
314 //returns difference of energies
315 return fPart1->E() - fPart2->E();
317 /****************************************************************/
320 Double_t AliAODPair::GetDeltaP()
322 //returns difference of momenta (scalars)
323 return fPart1->P() - fPart2->P();
325 /****************************************************************/
328 Double_t AliAODPair::GetDeltaPvector() //return difference of momenta
330 //returns legth of the momenta difference vector
332 return TMath::Sqrt(fPxDiff*fPxDiff + fPyDiff*fPyDiff + fPzDiff*fPzDiff);
334 /****************************************************************/
337 Double_t AliAODPair::GetDeltaPt()
339 //returns difference of Pz
340 return fPart1->Pt()-fPart2->Pt();
342 /****************************************************************/
345 Double_t AliAODPair::GetDeltaPx()
347 //returns difference of Pz
351 /****************************************************************/
353 Double_t AliAODPair::GetDeltaPy()
355 //returns difference of Py
360 /****************************************************************/
362 Double_t AliAODPair::GetDeltaPz()
364 //returns difference of Pz
368 /****************************************************************/
371 Double_t AliAODPair::GetDeltaPhi()
373 //returns difference of Phi
374 Double_t phi1 = fPart1->Phi();
375 Double_t phi2 = fPart2->Phi();
376 Double_t diff = phi1-phi2;
377 if (TMath::Abs(diff) > TMath::Pi())
379 if (phi1 > TMath::Pi())
381 phi1-=TMath::TwoPi();
385 phi2-=TMath::TwoPi();
391 /****************************************************************/
394 Double_t AliAODPair::GetDeltaTheta()
396 //returns difference of Theta
397 return fPart1->Theta()-fPart2->Theta();
399 /****************************************************************/