1 #include "AliAODPair.h"
2 //_________________________________________________________________________
3 ///////////////////////////////////////////////////////////////////////////
7 // class implements pair of particles and taking care of caluclation (almost)
8 // all of pair properties (Qinv, InvMass,...)
10 // more info: http://alisoft.cern.ch/people/skowron/analyzer/index.html
12 ////////////////////////////////////////////////////////////////////////////
14 #include "AliVAODParticle.h"
15 #include "AliTrackPoints.h"
19 /************************************************************************/
20 AliAODPair::AliAODPair(Bool_t rev):
25 fQSideLCMSNotCalc(kTRUE),
27 fQOutLCMSNotCalc(kTRUE),
29 fQLongLCMSNotCalc(kTRUE),
33 fInvMassNotCalc(kTRUE),
45 fMassSqrNotCalc(kTRUE),
48 fAvarageDistance(0.0),
49 fAvarageDistanceNotCalc(kTRUE),
61 fGammaLCMSNotCalc(kTRUE),
64 //value of rev defines if it is Swapped
65 //if you pass kTRUE swpaped pair will NOT be created
66 //though you wont be able to get the swaped pair from this pair
68 if(!rev) fSwappedPair = new AliAODPair(kTRUE); //if false create swaped pair
71 /************************************************************************/
73 AliAODPair::AliAODPair(AliVAODParticle* part1, AliVAODParticle* part2, Bool_t rev):
78 fQSideLCMSNotCalc(kTRUE),
80 fQOutLCMSNotCalc(kTRUE),
82 fQLongLCMSNotCalc(kTRUE),
86 fInvMassNotCalc(kTRUE),
98 fMassSqrNotCalc(kTRUE),
100 fQInvLNotCalc(kTRUE),
101 fAvarageDistance(0.0),
102 fAvarageDistanceNotCalc(kTRUE),
112 fDiffsNotCalc(kTRUE),
114 fGammaLCMSNotCalc(kTRUE),
117 //value of rev defines if it is Swapped
118 //if you pass kTRUE swpaped pair will NOT be created
119 //though you wont be able to get the swaped pair from this pair
121 if(!rev) fSwappedPair = new AliAODPair(part2,part1,kTRUE); //if false create swaped pair
124 /************************************************************************/
125 AliAODPair::AliAODPair(const AliAODPair& in):
131 fQSideLCMSNotCalc(kTRUE),
133 fQOutLCMSNotCalc(kTRUE),
135 fQLongLCMSNotCalc(kTRUE),
139 fInvMassNotCalc(kTRUE),
143 fKStarNotCalc(kTRUE),
151 fMassSqrNotCalc(kTRUE),
153 fQInvLNotCalc(kTRUE),
154 fAvarageDistance(0.0),
155 fAvarageDistanceNotCalc(kTRUE),
165 fDiffsNotCalc(kTRUE),
167 fGammaLCMSNotCalc(kTRUE),
173 /************************************************************************/
175 AliAODPair& AliAODPair::operator=(const AliAODPair& in)
181 /************************************************************************/
183 Double_t AliAODPair::GetInvMass()
185 //Returns qinv value for a pair
188 CalculateInvMassSqr(); //method is inline so we not waste th time for jumping into method
190 if(fInvMassSqr<0) fInvMass = TMath::Sqrt(-fInvMassSqr);
191 else fInvMass = TMath::Sqrt(fInvMassSqr);
193 fInvMassNotCalc = kFALSE;
197 /************************************************************************/
199 Double_t AliAODPair::GetQSideLCMS()
201 //return Q Side in Central Of Mass System in Longitudialy Comoving Frame
203 if (fQSideLCMSNotCalc)
205 fQSideLCMS = (fPart1->Px()*fPart2->Py()-fPart2->Px()*fPart1->Py())/GetKt();
206 fQSideLCMSNotCalc = kFALSE;
210 /************************************************************************/
212 Double_t AliAODPair::GetQOutLCMS()
214 //caculates Qout in Center Of Mass Longitudionally Co-Moving
220 if (fPart1->Mass() != fPart2->Mass())
224 Double_t beta = fPzSum/fESum;
225 Double_t gamma = GetGammaToLCMS();
226 Double_t el = gamma * (fPart1->E() - beta * fPart1->Pz());
227 Double_t x = ( fPart1->Px()*fPxSum + fPart1->Py()*fPySum) / ( 2.0*GetKt() );
228 beta = 2.0*GetKt()/GetMt();
229 gamma = GetMt()/GetQInv();
230 fQOutLCMS = gamma * (x - beta * el);
233 //beta=fPzSum/fESum; // Longit. V == beta
234 Double_t beta=fPzSum/fESum;
235 Double_t gamma = GetGammaToLCMS();
237 Double_t cosphi=fPxSum/(2.0*GetKt()); // cos(phi)
238 Double_t sinphi=fPySum/(2.0*GetKt()); // sin(phi)
240 // ROTATE(part1Px,part1Py,SPHI,CPHI,part1Px,part1Py);//ROT8
241 // ROTATE(part2Px,part2Py,SPHI,CPHI,part2Px,part2Py);//ROT8
243 tmp = fPart1->Px()*cosphi + fPart1->Py()*sinphi;
244 Double_t part1Py = fPart1->Py()*cosphi - fPart1->Px()*sinphi;
245 Double_t part1Px = tmp;
247 tmp = fPart2->Px()*cosphi + fPart2->Py()*sinphi;
248 Double_t part2Py = fPart2->Py()*cosphi - fPart2->Px()*sinphi;
249 Double_t part2Px = tmp;
252 // LTR(part1Pz,E1,beta,GetGammaToLCMS(),part1Pz,E1a);
253 // LTR(part2Pz,E2,beta,GetGammaToLCMS(),part2Pz,E2a);
254 Double_t part1Pz=gamma*(fPart1->Pz()-beta*fPart1->E());
255 Double_t part2Pz=gamma*(fPart2->Pz()-beta*fPart2->E());
257 Double_t part1P2=part1Px*part1Px+part1Py*part1Py+part1Pz*part1Pz;
258 Double_t part2P2=part2Px*part2Px+part2Py*part2Py+part2Pz*part2Pz;
259 Double_t part1E=TMath::Sqrt(fPart1->Mass()*fPart1->Mass()+part1P2);
260 Double_t part2E=TMath::Sqrt(fPart2->Mass()*fPart2->Mass()+part2P2);
261 Double_t sumE=part1E+part2E;
262 Double_t sumPx=part1Px+part2Px;
263 Double_t sumPy=part1Py+part2Py;
264 Double_t sumPZ=part1Pz+part2Pz;
265 Double_t sumP2=sumPx*sumPx+sumPy*sumPy+sumPZ*sumPZ;
267 Double_t relmass=TMath::Sqrt(sumE*sumE-sumP2);
268 Double_t hf = (fPart1->Mass()*fPart1->Mass() - fPart2->Mass()*fPart2->Mass())/(relmass*relmass);
269 fQOutLCMS=(part1Px-part2Px);//== id
270 fQOutLCMS=fQOutLCMS-sumPx*hf; //sumPx == fPxSum ale po rotacji i transf
274 Double_t k2 = fPxSum*fPxDiff+fPySum*fPyDiff;
275 fQOutLCMS = 0.5*k2/GetKt();
276 // if (non-id) fQOutLCMS=fQOutLCMS - sumPx*HF;
280 fQOutLCMSNotCalc = kFALSE;
284 /************************************************************************/
286 Double_t AliAODPair::GetQLongLCMS()
288 //return Q Long in Central Of Mass System in Longitudialy Comoving Frame
289 if (fQLongLCMSNotCalc)
293 Double_t beta = fPzSum/fESum;
294 fQLongLCMS = GetGammaToLCMS() * ( fPzDiff - beta*fEDiff );
295 fQLongLCMSNotCalc = kFALSE;
299 /************************************************************************/
301 Double_t AliAODPair::GetKt()
303 //calculates the evarage momentum of the pair
307 fKt = 0.5*TMath::Hypot(fPxSum,fPySum);
312 /************************************************************************/
314 Double_t AliAODPair::GetKStar()
316 //calculates invariant velocity difference
321 Double_t ptrans = fPxSum*fPxSum + fPySum*fPySum;
322 Double_t mtrans = fESum*fESum - fPzSum*fPzSum;
325 Error("GetKStar","Tranverse momentum bigger than transverse mass. Not normal for on-shell particles");
326 Error("GetKStar","Particle1:");
328 Error("GetKStar","Particle2:");
330 Error("GetKStar","");
333 fKStarNotCalc = kFALSE;
336 Double_t pinv = TMath::Sqrt(mtrans - ptrans);
338 Double_t q = (fPart1->Mass()*fPart1->Mass() - fPart2->Mass()*fPart2->Mass())/pinv;
345 Info("GetKStar","Sqrt of negative number q = %f",q);
346 Error("GetKStar","Particle1:");
348 Error("GetKStar","Particle2:");
351 fKStarNotCalc = kFALSE;
357 fKStarNotCalc = kFALSE;
361 /************************************************************************/
363 Double_t AliAODPair::GetQInv()
366 //warning for non-id particles you want to use 2*KStar
370 fQInv = TMath::Sqrt(TMath::Abs(fQInvL));
371 fQInvNotCalc = kFALSE;
375 /************************************************************************/
377 Double_t AliAODPair::GetGammaToLCMS()
379 //calculates gamma factor of the boost to LCMS
380 if(fGammaLCMSNotCalc)
383 Double_t beta = fPzSum/fESum;
384 fGammaLCMS = 1.0/TMath::Sqrt(1.0 - beta*beta);
385 fGammaLCMSNotCalc = kFALSE;
389 /************************************************************************/
391 Double_t AliAODPair::GetMt()
393 //Calculates transverse mass of the pair
397 fMt = TMath::Sqrt(fESum*fESum - fPzSum*fPzSum);
402 /************************************************************************/
404 Double_t AliAODPair::GetAvarageDistance()
406 //returns and buffers avarage distance between two tracks calculated
407 // out of track points (see AliAODTrackPoints class)
409 if (fAvarageDistanceNotCalc)
411 fAvarageDistance = AvDistance();
412 fAvarageDistanceNotCalc = kFALSE;
414 return fAvarageDistance;
416 /************************************************************************/
418 Double_t AliAODPair::AvDistance()
420 //returns avarage distance between two tracks in range
421 //as defined in Track-Points of AliVAODParticle
422 //returns negative value if error uccured f.g. tracks do not have track-points
423 AliTrackPoints* tpts1 = fPart1->GetTPCTrackPoints();
425 {//it could be simulated pair
426 // Warning("GetValue","Track 1 does not have Track Points. Pair NOT Passed.");
430 AliTrackPoints* tpts2 = fPart2->GetTPCTrackPoints();
433 // Warning("GetValue","Track 2 does not have Track Points. Pair NOT Passed.");
437 return tpts1->AvarageDistance(*tpts2);