]> git.uio.no Git - u/mrichter/AliRoot.git/blame - STEER/ESD/AliKFParticleBase.cxx
git://git.uio.no / u / mrichter / AliRoot.git / blame
? search:
summary | shortlog | log | commit | commitdiff | tree
blob | blame (incremental) | history | HEAD
Coverity fix
[u/mrichter/AliRoot.git] / STEER / ESD / AliKFParticleBase.cxx
CommitLineData
f826d409 1//---------------------------------------------------------------------------------
2// Implementation of the AliKFParticleBase class
3// .
57ddc2cb 4// @author S.Gorbunov, I.Kisel, I.Kulakov, M.Zyzak
f826d409 5// @version 1.0
6// @since 13.05.07
7//
8// Class to reconstruct and store the decayed particle parameters.
9// The method is described in CBM-SOFT note 2007-003,
10// ``Reconstruction of decayed particles based on the Kalman filter'',
11// http://www.gsi.de/documents/DOC-2007-May-14-1.pdf
12//
13// This class describes general mathematics which is used by AliKFParticle class
14//
15// -= Copyright &copy ALICE HLT Group =-
16//_________________________________________________________________________________
17
18
19#include "AliKFParticleBase.h"
20#include "TMath.h"
21
57ddc2cb 22#include <iostream>
effa6338 23ClassImp(AliKFParticleBase)
f826d409 24
25
57ddc2cb 26AliKFParticleBase::AliKFParticleBase() :fQ(0), fNDF(-3), fChi2(0), fSFromDecay(0), fAtProductionVertex(0), fIsLinearized(0),
27 fConstructMethod(2), SumDaughterMass(0), fMassHypo(-1)
f826d409 28{
29 //* Constructor
30
31 Initialize();
32}
e7b09c95 33
34void AliKFParticleBase::Initialize( const Double_t Param[], const Double_t Cov[], Int_t Charge, Double_t Mass )
35{
36 // Constructor from "cartesian" track, particle mass hypothesis should be provided
37 //
38 // Param[6] = { X, Y, Z, Px, Py, Pz } - position and momentum
39 // Cov [21] = lower-triangular part of the covariance matrix:
40 //
41 // ( 0 . . . . . )
42 // ( 1 2 . . . . )
43 // Cov. matrix = ( 3 4 5 . . . ) - numbering of covariance elements in Cov[]
44 // ( 6 7 8 9 . . )
45 // ( 10 11 12 13 14 . )
46 // ( 15 16 17 18 19 20 )
47
48
49 for( Int_t i=0; i<6 ; i++ ) fP[i] = Param[i];
50 for( Int_t i=0; i<21; i++ ) fC[i] = Cov[i];
51
52 Double_t energy = TMath::Sqrt( Mass*Mass + fP[3]*fP[3] + fP[4]*fP[4] + fP[5]*fP[5]);
53 fP[6] = energy;
54 fP[7] = 0;
55 fQ = Charge;
56 fNDF = 0;
57 fChi2 = 0;
58 fAtProductionVertex = 0;
59 fIsLinearized = 0;
60 fSFromDecay = 0;
61
62 Double_t energyInv = 1./energy;
63 Double_t
64 h0 = fP[3]*energyInv,
65 h1 = fP[4]*energyInv,
66 h2 = fP[5]*energyInv;
67
68 fC[21] = h0*fC[ 6] + h1*fC[10] + h2*fC[15];
69 fC[22] = h0*fC[ 7] + h1*fC[11] + h2*fC[16];
70 fC[23] = h0*fC[ 8] + h1*fC[12] + h2*fC[17];
71 fC[24] = h0*fC[ 9] + h1*fC[13] + h2*fC[18];
72 fC[25] = h0*fC[13] + h1*fC[14] + h2*fC[19];
73 fC[26] = h0*fC[18] + h1*fC[19] + h2*fC[20];
706952f5 74 fC[27] = ( h0*h0*fC[ 9] + h1*h1*fC[14] + h2*h2*fC[20]
75 + 2*(h0*h1*fC[13] + h0*h2*fC[18] + h1*h2*fC[19] ) );
e7b09c95 76 for( Int_t i=28; i<36; i++ ) fC[i] = 0;
77 fC[35] = 1.;
57ddc2cb 78
79 SumDaughterMass = Mass;
80 fMassHypo = Mass;
e7b09c95 81}
82
f826d409 83void AliKFParticleBase::Initialize()
84{
85 //* Initialise covariance matrix and set current parameters to 0.0
86
87 for( Int_t i=0; i<8; i++) fP[i] = 0;
88 for(Int_t i=0;i<36;++i) fC[i]=0.;
89 fC[0] = fC[2] = fC[5] = 100.;
90 fC[35] = 1.;
91 fNDF = -3;
92 fChi2 = 0.;
93 fQ = 0;
94 fSFromDecay = 0;
95 fAtProductionVertex = 0;
96 fVtxGuess[0]=fVtxGuess[1]=fVtxGuess[2]=0.;
97 fIsLinearized = 0;
57ddc2cb 98 SumDaughterMass = 0;
99 fMassHypo = -1;
f826d409 100}
101
102void AliKFParticleBase::SetVtxGuess( Double_t x, Double_t y, Double_t z )
103{
104 //* Set decay vertex parameters for linearisation
105
106 fVtxGuess[0] = x;
107 fVtxGuess[1] = y;
108 fVtxGuess[2] = z;
109 fIsLinearized = 1;
110}
111
5fc72f28 112Int_t AliKFParticleBase::GetMomentum( Double_t &p, Double_t &error ) const
f826d409 113{
114 //* Calculate particle momentum
115
116 Double_t x = fP[3];
117 Double_t y = fP[4];
118 Double_t z = fP[5];
55ac3e1e 119
f826d409 120 Double_t x2 = x*x;
121 Double_t y2 = y*y;
122 Double_t z2 = z*z;
123 Double_t p2 = x2+y2+z2;
5fc72f28 124 p = TMath::Sqrt(p2);
55ac3e1e 125
5fc72f28 126 error = (x2*fC[9]+y2*fC[14]+z2*fC[20] + 2*(x*y*fC[13]+x*z*fC[18]+y*z*fC[19]) );
55ac3e1e 127 if( error>1.e-16 && p>1.e-4 ){
5fc72f28 128 error = TMath::Sqrt(error)/p;
f826d409 129 return 0;
130 }
55ac3e1e 131 error = 1.e8;
f826d409 132 return 1;
133}
134
5fc72f28 135Int_t AliKFParticleBase::GetPt( Double_t &pt, Double_t &error ) const
706952f5 136{
137 //* Calculate particle transverse momentum
138
139 Double_t px = fP[3];
140 Double_t py = fP[4];
141 Double_t px2 = px*px;
142 Double_t py2 = py*py;
143 Double_t pt2 = px2+py2;
5fc72f28 144 pt = TMath::Sqrt(pt2);
145 error = (px2*fC[9] + py2*fC[14] + 2*px*py*fC[13] );
146 if( error>0 && pt>1.e-4 ){
147 error = TMath::Sqrt(error)/pt;
706952f5 148 return 0;
149 }
5fc72f28 150 error = 1.e10;
706952f5 151 return 1;
152}
153
5fc72f28 154Int_t AliKFParticleBase::GetEta( Double_t &eta, Double_t &error ) const
706952f5 155{
156 //* Calculate particle pseudorapidity
157
158 Double_t px = fP[3];
159 Double_t py = fP[4];
160 Double_t pz = fP[5];
161 Double_t pt2 = px*px + py*py;
162 Double_t p2 = pt2 + pz*pz;
163 Double_t p = TMath::Sqrt(p2);
164 Double_t a = p + pz;
165 Double_t b = p - pz;
5fc72f28 166 eta = 1.e10;
706952f5 167 if( b > 1.e-8 ){
168 Double_t c = a/b;
a65041d0 169 if( c>1.e-8 ) eta = 0.5*TMath::Log(c);
706952f5 170 }
171 Double_t h3 = -px*pz;
a65041d0 172 Double_t h4 = -py*pz;
173 Double_t pt4 = pt2*pt2;
174 Double_t p2pt4 = p2*pt4;
175 error = (h3*h3*fC[9] + h4*h4*fC[14] + pt4*fC[20] + 2*( h3*(h4*fC[13] + fC[18]*pt2) + pt2*h4*fC[19] ) );
706952f5 176
a65041d0 177 if( error>0 && p2pt4>1.e-10 ){
178 error = TMath::Sqrt(error/p2pt4);
706952f5 179 return 0;
180 }
a65041d0 181
5fc72f28 182 error = 1.e10;
706952f5 183 return 1;
184}
185
5fc72f28 186Int_t AliKFParticleBase::GetPhi( Double_t &phi, Double_t &error ) const
706952f5 187{
188 //* Calculate particle polar angle
189
190 Double_t px = fP[3];
191 Double_t py = fP[4];
192 Double_t px2 = px*px;
193 Double_t py2 = py*py;
194 Double_t pt2 = px2 + py2;
5fc72f28 195 phi = TMath::ATan2(py,px);
196 error = (py2*fC[9] + px2*fC[14] - 2*px*py*fC[13] );
197 if( error>0 && pt2>1.e-4 ){
198 error = TMath::Sqrt(error)/pt2;
706952f5 199 return 0;
200 }
5fc72f28 201 error = 1.e10;
706952f5 202 return 1;
203}
204
5fc72f28 205Int_t AliKFParticleBase::GetR( Double_t &r, Double_t &error ) const
706952f5 206{
207 //* Calculate distance to the origin
208
209 Double_t x = fP[0];
210 Double_t y = fP[1];
211 Double_t x2 = x*x;
212 Double_t y2 = y*y;
5fc72f28 213 r = TMath::Sqrt(x2 + y2);
214 error = (x2*fC[0] + y2*fC[2] - 2*x*y*fC[1] );
215 if( error>0 && r>1.e-4 ){
216 error = TMath::Sqrt(error)/r;
706952f5 217 return 0;
218 }
5fc72f28 219 error = 1.e10;
706952f5 220 return 1;
221}
222
5fc72f28 223Int_t AliKFParticleBase::GetMass( Double_t &m, Double_t &error ) const
f826d409 224{
225 //* Calculate particle mass
226
227 // s = sigma^2 of m2/2
228
229 Double_t s = ( fP[3]*fP[3]*fC[9] + fP[4]*fP[4]*fC[14] + fP[5]*fP[5]*fC[20]
230 + fP[6]*fP[6]*fC[27]
231 +2*( + fP[3]*fP[4]*fC[13] + fP[5]*(fP[3]*fC[18] + fP[4]*fC[19])
232 - fP[6]*( fP[3]*fC[24] + fP[4]*fC[25] + fP[5]*fC[26] ) )
233 );
57ddc2cb 234// Double_t m2 = TMath::Abs(fP[6]*fP[6] - fP[3]*fP[3] - fP[4]*fP[4] - fP[5]*fP[5]);
235// m = TMath::Sqrt(m2);
236// if( m>1.e-10 ){
237// if( s>=0 ){
238// error = TMath::Sqrt(s)/m;
239// return 0;
240// }
241// }
242// error = 1.e20;
243// return 1;
244 Double_t m2 = (fP[6]*fP[6] - fP[3]*fP[3] - fP[4]*fP[4] - fP[5]*fP[5]);
245
246 if(m2<0.)
247 {
248 error = 1.e20;
249 m = -TMath::Sqrt(-m2);
250 return 1;
251 }
252
5fc72f28 253 m = TMath::Sqrt(m2);
57ddc2cb 254 if( m>1.e-6 ){
255 if( s >= 0 ) {
5fc72f28 256 error = TMath::Sqrt(s)/m;
616ffc76 257 return 0;
258 }
f826d409 259 }
57ddc2cb 260 else {
261 error = 1.e20;
262 return 0;
263 }
5fc72f28 264 error = 1.e20;
57ddc2cb 265
f826d409 266 return 1;
267}
268
269
5fc72f28 270Int_t AliKFParticleBase::GetDecayLength( Double_t &l, Double_t &error ) const
f826d409 271{
272 //* Calculate particle decay length [cm]
273
274 Double_t x = fP[3];
275 Double_t y = fP[4];
276 Double_t z = fP[5];
277 Double_t t = fP[7];
278 Double_t x2 = x*x;
279 Double_t y2 = y*y;
280 Double_t z2 = z*z;
281 Double_t p2 = x2+y2+z2;
5fc72f28 282 l = t*TMath::Sqrt(p2);
f826d409 283 if( p2>1.e-4){
5fc72f28 284 error = p2*fC[35] + t*t/p2*(x2*fC[9]+y2*fC[14]+z2*fC[20]
f826d409 285 + 2*(x*y*fC[13]+x*z*fC[18]+y*z*fC[19]) )
286 + 2*t*(x*fC[31]+y*fC[32]+z*fC[33]);
5fc72f28 287 error = TMath::Sqrt(TMath::Abs(error));
f826d409 288 return 0;
289 }
5fc72f28 290 error = 1.e20;
f826d409 291 return 1;
292}
293
446ce366 294Int_t AliKFParticleBase::GetDecayLengthXY( Double_t &l, Double_t &error ) const
295{
296 //* Calculate particle decay length in XY projection [cm]
297
298 Double_t x = fP[3];
299 Double_t y = fP[4];
300 Double_t t = fP[7];
301 Double_t x2 = x*x;
302 Double_t y2 = y*y;
303 Double_t pt2 = x2+y2;
304 l = t*TMath::Sqrt(pt2);
305 if( pt2>1.e-4){
306 error = pt2*fC[35] + t*t/pt2*(x2*fC[9]+y2*fC[14] + 2*x*y*fC[13] )
307 + 2*t*(x*fC[31]+y*fC[32]);
308 error = TMath::Sqrt(TMath::Abs(error));
309 return 0;
310 }
311 error = 1.e20;
312 return 1;
313}
314
315
5fc72f28 316Int_t AliKFParticleBase::GetLifeTime( Double_t &tauC, Double_t &error ) const
f826d409 317{
318 //* Calculate particle decay time [s]
319
320 Double_t m, dm;
321 GetMass( m, dm );
322 Double_t cTM = (-fP[3]*fC[31] - fP[4]*fC[32] - fP[5]*fC[33] + fP[6]*fC[34]);
5fc72f28 323 tauC = fP[7]*m;
324 error = m*m*fC[35] + 2*fP[7]*cTM + fP[7]*fP[7]*dm*dm;
325 if( error > 0 ){
326 error = TMath::Sqrt( error );
f826d409 327 return 0;
328 }
5fc72f28 329 error = 1.e20;
f826d409 330 return 1;
331}
332
333
334void AliKFParticleBase::operator +=( const AliKFParticleBase &Daughter )
335{
336 //* Add daughter via operator+=
337
338 AddDaughter( Daughter );
339}
340
706952f5 341Double_t AliKFParticleBase::GetSCorrection( const Double_t Part[], const Double_t XYZ[] )
342{
343 //* Get big enough correction for S error to let the particle Part be fitted to XYZ point
344
345 Double_t d[3] = { XYZ[0]-Part[0], XYZ[1]-Part[1], XYZ[2]-Part[2] };
346 Double_t p2 = Part[3]*Part[3]+Part[4]*Part[4]+Part[5]*Part[5];
a65041d0 347 Double_t sigmaS = (p2>1.e-4) ? ( 10.1+3.*TMath::Sqrt( d[0]*d[0]+d[1]*d[1]+d[2]*d[2]) )/TMath::Sqrt(p2) : 1.;
706952f5 348 return sigmaS;
349}
616ffc76 350
351void AliKFParticleBase::GetMeasurement( const Double_t XYZ[], Double_t m[], Double_t V[] ) const
352{
e7b09c95 353 //* Get additional covariances V used during measurement
354
616ffc76 355 Double_t b[3];
356 GetFieldValue( XYZ, b );
357 const Double_t kCLight = 0.000299792458;
358 b[0]*=kCLight; b[1]*=kCLight; b[2]*=kCLight;
359
360 Transport( GetDStoPoint(XYZ), m, V );
361
706952f5 362 Double_t sigmaS = GetSCorrection( m, XYZ );
616ffc76 363
364 Double_t h[6];
365
366 h[0] = m[3]*sigmaS;
367 h[1] = m[4]*sigmaS;
368 h[2] = m[5]*sigmaS;
369 h[3] = ( h[1]*b[2]-h[2]*b[1] )*GetQ();
370 h[4] = ( h[2]*b[0]-h[0]*b[2] )*GetQ();
371 h[5] = ( h[0]*b[1]-h[1]*b[0] )*GetQ();
372
616ffc76 373 V[ 0]+= h[0]*h[0];
374 V[ 1]+= h[1]*h[0];
375 V[ 2]+= h[1]*h[1];
376 V[ 3]+= h[2]*h[0];
377 V[ 4]+= h[2]*h[1];
378 V[ 5]+= h[2]*h[2];
379
380 V[ 6]+= h[3]*h[0];
381 V[ 7]+= h[3]*h[1];
382 V[ 8]+= h[3]*h[2];
383 V[ 9]+= h[3]*h[3];
384
385 V[10]+= h[4]*h[0];
386 V[11]+= h[4]*h[1];
387 V[12]+= h[4]*h[2];
388 V[13]+= h[4]*h[3];
389 V[14]+= h[4]*h[4];
390
391 V[15]+= h[5]*h[0];
392 V[16]+= h[5]*h[1];
393 V[17]+= h[5]*h[2];
394 V[18]+= h[5]*h[3];
395 V[19]+= h[5]*h[4];
396 V[20]+= h[5]*h[5];
397}
398
f826d409 399void AliKFParticleBase::AddDaughter( const AliKFParticleBase &Daughter )
400{
616ffc76 401 if( fNDF<-1 ){ // first daughter -> just copy
402 fNDF = -1;
403 fQ = Daughter.GetQ();
404 for( Int_t i=0; i<7; i++) fP[i] = Daughter.fP[i];
405 for( Int_t i=0; i<28; i++) fC[i] = Daughter.fC[i];
406 fSFromDecay = 0;
57ddc2cb 407 fMassHypo = Daughter.fMassHypo;
408 SumDaughterMass = Daughter.SumDaughterMass;
616ffc76 409 return;
410 }
411
57ddc2cb 412 if(fConstructMethod == 0)
413 AddDaughterWithEnergyFit(Daughter);
414 else if(fConstructMethod == 1)
415 AddDaughterWithEnergyCalc(Daughter);
416 else if(fConstructMethod == 2)
417 AddDaughterWithEnergyFitMC(Daughter);
418
419 SumDaughterMass += Daughter.SumDaughterMass;
420 fMassHypo = -1;
421}
422
423void AliKFParticleBase::AddDaughterWithEnergyFit( const AliKFParticleBase &Daughter )
424{
425 //* Energy considered as an independent veriable, fitted independently from momentum, without any constraints on mass
426
427 //* Add daughter
428
f826d409 429 TransportToDecayVertex();
430
431 Double_t b[3];
432 Int_t maxIter = 1;
433
434 if( !fIsLinearized ){
435 if( fNDF==-1 ){
436 Double_t ds, ds1;
616ffc76 437 GetDStoParticle(Daughter, ds, ds1);
f826d409 438 TransportToDS( ds );
616ffc76 439 Double_t m[8];
440 Double_t mCd[36];
441 Daughter.Transport( ds1, m, mCd );
442 fVtxGuess[0] = .5*( fP[0] + m[0] );
443 fVtxGuess[1] = .5*( fP[1] + m[1] );
444 fVtxGuess[2] = .5*( fP[2] + m[2] );
445 } else {
446 fVtxGuess[0] = fP[0];
447 fVtxGuess[1] = fP[1];
448 fVtxGuess[2] = fP[2];
f826d409 449 }
f826d409 450 maxIter = 3;
451 }
452
453 for( Int_t iter=0; iter<maxIter; iter++ ){
454
455 {
456 GetFieldValue( fVtxGuess, b );
457 const Double_t kCLight = 0.000299792458;
458 b[0]*=kCLight; b[1]*=kCLight; b[2]*=kCLight;
459 }
f826d409 460
616ffc76 461 Double_t *ffP = fP, *ffC = fC, tmpP[8], tmpC[36];
de0d0ceb 462 if( fNDF==-1 ){
616ffc76 463 GetMeasurement( fVtxGuess, tmpP, tmpC );
464 ffP = tmpP;
465 ffC = tmpC;
f826d409 466 }
467
e7b09c95 468 Double_t m[8], mV[36];
de0d0ceb 469
e7b09c95 470 if( Daughter.fC[35]>0 ){
471 Daughter.GetMeasurement( fVtxGuess, m, mV );
472 } else {
473 for( Int_t i=0; i<8; i++ ) m[i] = Daughter.fP[i];
474 for( Int_t i=0; i<36; i++ ) mV[i] = Daughter.fC[i];
475 }
f826d409 476 //*
477
478 Double_t mS[6];
479 {
616ffc76 480 Double_t mSi[6] = { ffC[0]+mV[0],
481 ffC[1]+mV[1], ffC[2]+mV[2],
482 ffC[3]+mV[3], ffC[4]+mV[4], ffC[5]+mV[5] };
57ddc2cb 483
f826d409 484 mS[0] = mSi[2]*mSi[5] - mSi[4]*mSi[4];
485 mS[1] = mSi[3]*mSi[4] - mSi[1]*mSi[5];
486 mS[2] = mSi[0]*mSi[5] - mSi[3]*mSi[3];
487 mS[3] = mSi[1]*mSi[4] - mSi[2]*mSi[3];
488 mS[4] = mSi[1]*mSi[3] - mSi[0]*mSi[4];
489 mS[5] = mSi[0]*mSi[2] - mSi[1]*mSi[1];
706952f5 490
57ddc2cb 491 Double_t s = ( mSi[0]*mS[0] + mSi[1]*mS[1] + mSi[3]*mS[3] );
492 s = ( TMath::Abs(s) > 1.E-20 ) ?1./s :0;
f826d409 493 mS[0]*=s;
494 mS[1]*=s;
495 mS[2]*=s;
496 mS[3]*=s;
497 mS[4]*=s;
498 mS[5]*=s;
499 }
f826d409 500 //* Residual (measured - estimated)
57ddc2cb 501
616ffc76 502 Double_t zeta[3] = { m[0]-ffP[0], m[1]-ffP[1], m[2]-ffP[2] };
de0d0ceb 503
f826d409 504 //* CHt = CH' - D'
57ddc2cb 505
f826d409 506 Double_t mCHt0[7], mCHt1[7], mCHt2[7];
57ddc2cb 507
616ffc76 508 mCHt0[0]=ffC[ 0] ; mCHt1[0]=ffC[ 1] ; mCHt2[0]=ffC[ 3] ;
509 mCHt0[1]=ffC[ 1] ; mCHt1[1]=ffC[ 2] ; mCHt2[1]=ffC[ 4] ;
510 mCHt0[2]=ffC[ 3] ; mCHt1[2]=ffC[ 4] ; mCHt2[2]=ffC[ 5] ;
511 mCHt0[3]=ffC[ 6]-mV[ 6]; mCHt1[3]=ffC[ 7]-mV[ 7]; mCHt2[3]=ffC[ 8]-mV[ 8];
512 mCHt0[4]=ffC[10]-mV[10]; mCHt1[4]=ffC[11]-mV[11]; mCHt2[4]=ffC[12]-mV[12];
513 mCHt0[5]=ffC[15]-mV[15]; mCHt1[5]=ffC[16]-mV[16]; mCHt2[5]=ffC[17]-mV[17];
514 mCHt0[6]=ffC[21]-mV[21]; mCHt1[6]=ffC[22]-mV[22]; mCHt2[6]=ffC[23]-mV[23];
f826d409 515
516 //* Kalman gain K = mCH'*S
517
518 Double_t k0[7], k1[7], k2[7];
519
520 for(Int_t i=0;i<7;++i){
521 k0[i] = mCHt0[i]*mS[0] + mCHt1[i]*mS[1] + mCHt2[i]*mS[3];
522 k1[i] = mCHt0[i]*mS[1] + mCHt1[i]*mS[2] + mCHt2[i]*mS[4];
523 k2[i] = mCHt0[i]*mS[3] + mCHt1[i]*mS[4] + mCHt2[i]*mS[5];
524 }
525
4bbc290d 526 //* New estimation of the vertex position
f826d409 527
528 if( iter<maxIter-1 ){
529 for(Int_t i=0; i<3; ++i)
616ffc76 530 fVtxGuess[i]= ffP[i] + k0[i]*zeta[0]+k1[i]*zeta[1]+k2[i]*zeta[2];
f826d409 531 continue;
532 }
533
534 // last itearation -> update the particle
535
536 //* Add the daughter momentum to the particle momentum
537
616ffc76 538 ffP[ 3] += m[ 3];
539 ffP[ 4] += m[ 4];
540 ffP[ 5] += m[ 5];
541 ffP[ 6] += m[ 6];
f826d409 542
616ffc76 543 ffC[ 9] += mV[ 9];
544 ffC[13] += mV[13];
545 ffC[14] += mV[14];
546 ffC[18] += mV[18];
547 ffC[19] += mV[19];
548 ffC[20] += mV[20];
549 ffC[24] += mV[24];
550 ffC[25] += mV[25];
551 ffC[26] += mV[26];
552 ffC[27] += mV[27];
f826d409 553
de0d0ceb 554
555 //* New estimation of the vertex position r += K*zeta
f826d409 556
557 for(Int_t i=0;i<7;++i)
616ffc76 558 fP[i] = ffP[i] + k0[i]*zeta[0] + k1[i]*zeta[1] + k2[i]*zeta[2];
f826d409 559
560 //* New covariance matrix C -= K*(mCH')'
de0d0ceb 561
f826d409 562 for(Int_t i=0, k=0;i<7;++i){
de0d0ceb 563 for(Int_t j=0;j<=i;++j,++k){
616ffc76 564 fC[k] = ffC[k] - (k0[i]*mCHt0[j] + k1[i]*mCHt1[j] + k2[i]*mCHt2[j] );
de0d0ceb 565 }
f826d409 566 }
de0d0ceb 567
f826d409 568 //* Calculate Chi^2
569
570 fNDF += 2;
571 fQ += Daughter.GetQ();
572 fSFromDecay = 0;
573 fChi2 += (mS[0]*zeta[0] + mS[1]*zeta[1] + mS[3]*zeta[2])*zeta[0]
574 + (mS[1]*zeta[0] + mS[2]*zeta[1] + mS[4]*zeta[2])*zeta[1]
706952f5 575 + (mS[3]*zeta[0] + mS[4]*zeta[1] + mS[5]*zeta[2])*zeta[2];
de0d0ceb 576
f826d409 577 }
578}
579
57ddc2cb 580void AliKFParticleBase::AddDaughterWithEnergyCalc( const AliKFParticleBase &Daughter )
581{
582 //* Energy considered as a dependent variable, calculated from the momentum and mass hypothesis
583
584 //* Add daughter
585
586 TransportToDecayVertex();
587
588 Double_t b[3];
589 Int_t maxIter = 1;
590
591 if( !fIsLinearized ){
592 if( fNDF==-1 ){
593 Double_t ds, ds1;
594 GetDStoParticle(Daughter, ds, ds1);
595 TransportToDS( ds );
596 Double_t m[8];
597 Double_t mCd[36];
598 Daughter.Transport( ds1, m, mCd );
599 fVtxGuess[0] = .5*( fP[0] + m[0] );
600 fVtxGuess[1] = .5*( fP[1] + m[1] );
601 fVtxGuess[2] = .5*( fP[2] + m[2] );
602 } else {
603 fVtxGuess[0] = fP[0];
604 fVtxGuess[1] = fP[1];
605 fVtxGuess[2] = fP[2];
606 }
607 maxIter = 3;
608 }
609
610 for( Int_t iter=0; iter<maxIter; iter++ ){
611
612 {
613 GetFieldValue( fVtxGuess, b );
614 const Double_t kCLight = 0.000299792458;
615 b[0]*=kCLight; b[1]*=kCLight; b[2]*=kCLight;
616 }
617
618 Double_t *ffP = fP, *ffC = fC, tmpP[8], tmpC[36];
619 if( fNDF==-1 ){
620 GetMeasurement( fVtxGuess, tmpP, tmpC );
621 ffP = tmpP;
622 ffC = tmpC;
623 }
624
625 Double_t m[8], mV[36];
626
627 if( Daughter.fC[35]>0 ){
628 Daughter.GetMeasurement( fVtxGuess, m, mV );
629 } else {
630 for( Int_t i=0; i<8; i++ ) m[i] = Daughter.fP[i];
631 for( Int_t i=0; i<36; i++ ) mV[i] = Daughter.fC[i];
632 }
633
634 double Mass_mf2 = m[6]*m[6] - (m[3]*m[3] + m[4]*m[4] + m[5]*m[5]);
635 double Mass_rf2 = fP[6]*fP[6] - (fP[3]*fP[3] + fP[4]*fP[4] + fP[5]*fP[5]);
636
637 //*
638
639 Double_t mS[6];
640 {
641 Double_t mSi[6] = { ffC[0]+mV[0],
642 ffC[1]+mV[1], ffC[2]+mV[2],
643 ffC[3]+mV[3], ffC[4]+mV[4], ffC[5]+mV[5] };
644
645 mS[0] = mSi[2]*mSi[5] - mSi[4]*mSi[4];
646 mS[1] = mSi[3]*mSi[4] - mSi[1]*mSi[5];
647 mS[2] = mSi[0]*mSi[5] - mSi[3]*mSi[3];
648 mS[3] = mSi[1]*mSi[4] - mSi[2]*mSi[3];
649 mS[4] = mSi[1]*mSi[3] - mSi[0]*mSi[4];
650 mS[5] = mSi[0]*mSi[2] - mSi[1]*mSi[1];
651
652 Double_t s = ( mSi[0]*mS[0] + mSi[1]*mS[1] + mSi[3]*mS[3] );
653
654 s = ( s > 1.E-20 ) ?1./s :0;
655 mS[0]*=s;
656 mS[1]*=s;
657 mS[2]*=s;
658 mS[3]*=s;
659 mS[4]*=s;
660 mS[5]*=s;
661 }
662
663 //* Residual (measured - estimated)
664
665 Double_t zeta[3] = { m[0]-ffP[0], m[1]-ffP[1], m[2]-ffP[2] };
666
667 //* CHt = CH' - D'
668
669 Double_t mCHt0[6], mCHt1[6], mCHt2[6];
670
671 mCHt0[0]=ffC[ 0] ; mCHt1[0]=ffC[ 1] ; mCHt2[0]=ffC[ 3] ;
672 mCHt0[1]=ffC[ 1] ; mCHt1[1]=ffC[ 2] ; mCHt2[1]=ffC[ 4] ;
673 mCHt0[2]=ffC[ 3] ; mCHt1[2]=ffC[ 4] ; mCHt2[2]=ffC[ 5] ;
674 mCHt0[3]=ffC[ 6]-mV[ 6]; mCHt1[3]=ffC[ 7]-mV[ 7]; mCHt2[3]=ffC[ 8]-mV[ 8];
675 mCHt0[4]=ffC[10]-mV[10]; mCHt1[4]=ffC[11]-mV[11]; mCHt2[4]=ffC[12]-mV[12];
676 mCHt0[5]=ffC[15]-mV[15]; mCHt1[5]=ffC[16]-mV[16]; mCHt2[5]=ffC[17]-mV[17];
677
678 //* Kalman gain K = mCH'*S
679
680 Double_t k0[6], k1[6], k2[6];
681
682 for(Int_t i=0;i<6;++i){
683 k0[i] = mCHt0[i]*mS[0] + mCHt1[i]*mS[1] + mCHt2[i]*mS[3];
684 k1[i] = mCHt0[i]*mS[1] + mCHt1[i]*mS[2] + mCHt2[i]*mS[4];
685 k2[i] = mCHt0[i]*mS[3] + mCHt1[i]*mS[4] + mCHt2[i]*mS[5];
686 }
687
688 //* New estimation of the vertex position
689
690 if( iter<maxIter-1 ){
691 for(Int_t i=0; i<3; ++i)
692 fVtxGuess[i]= ffP[i] + k0[i]*zeta[0]+k1[i]*zeta[1]+k2[i]*zeta[2];
693 continue;
694 }
695
696 //* find mf and Vf - optimum value of the measurement and its covariance matrix
697 //* mVHt = V*H'
698 Double_t mVHt0[6], mVHt1[6], mVHt2[6];
699
700 mVHt0[0]= mV[ 0] ; mVHt1[0]= mV[ 1] ; mVHt2[0]= mV[ 3] ;
701 mVHt0[1]= mV[ 1] ; mVHt1[1]= mV[ 2] ; mVHt2[1]= mV[ 4] ;
702 mVHt0[2]= mV[ 3] ; mVHt1[2]= mV[ 4] ; mVHt2[2]= mV[ 5] ;
703 mVHt0[3]= mV[ 6] ; mVHt1[3]= mV[ 7] ; mVHt2[3]= mV[ 8] ;
704 mVHt0[4]= mV[10] ; mVHt1[4]= mV[11] ; mVHt2[4]= mV[12] ;
705 mVHt0[5]= mV[15] ; mVHt1[5]= mV[16] ; mVHt2[5]= mV[17] ;
706
707 //* Kalman gain Km = mCH'*S
708
709 Double_t km0[6], km1[6], km2[6];
710
711 for(Int_t i=0;i<6;++i){
712 km0[i] = mVHt0[i]*mS[0] + mVHt1[i]*mS[1] + mVHt2[i]*mS[3];
713 km1[i] = mVHt0[i]*mS[1] + mVHt1[i]*mS[2] + mVHt2[i]*mS[4];
714 km2[i] = mVHt0[i]*mS[3] + mVHt1[i]*mS[4] + mVHt2[i]*mS[5];
715 }
716
717 Double_t mf[7] = { m[0], m[1], m[2], m[3], m[4], m[5], m[6] };
718
719 for(Int_t i=0;i<6;++i)
720 mf[i] = mf[i] - km0[i]*zeta[0] - km1[i]*zeta[1] - km2[i]*zeta[2];
721
722 Double_t E_mf = TMath::Sqrt( Mass_mf2 + (mf[3]*mf[3] + mf[4]*mf[4] + mf[5]*mf[5]) );
723
724 Double_t Vf[28];
725 for(Int_t iC=0; iC<28; iC++)
726 Vf[iC] = mV[iC];
727
728 //* hmf = d(E_mf)/d(mf)
729 Double_t hmf[7];
121dc8bd 730 if( TMath::Abs(E_mf) < 1.e-10) hmf[3] = 0; else hmf[3] = mf[3]/E_mf;
731 if( TMath::Abs(E_mf) < 1.e-10) hmf[4] = 0; else hmf[4] = mf[4]/E_mf;
732 if( TMath::Abs(E_mf) < 1.e-10) hmf[5] = 0; else hmf[5] = mf[5]/E_mf;
733// if( TMath::Abs(E_mf) < 1.e-10) hmf[6] = 0; else hmf[6] = mf[6]/E_mf;
57ddc2cb 734 hmf[6] = 0;
735
736 for(Int_t i=0, k=0;i<6;++i){
737 for(Int_t j=0;j<=i;++j,++k){
738 Vf[k] = Vf[k] - (km0[i]*mVHt0[j] + km1[i]*mVHt1[j] + km2[i]*mVHt2[j] );
739 }
740 }
741 Double_t Vf24 = Vf[24], Vf25 = Vf[25], Vf26 = Vf[26];
742 Vf[21] = Vf[6 ]*hmf[3] + Vf[10]*hmf[4] + Vf[15]*hmf[5] + Vf[21]*hmf[6];
743 Vf[22] = Vf[7 ]*hmf[3] + Vf[11]*hmf[4] + Vf[16]*hmf[5] + Vf[22]*hmf[6];
744 Vf[23] = Vf[8 ]*hmf[3] + Vf[12]*hmf[4] + Vf[17]*hmf[5] + Vf[23]*hmf[6];
745 Vf[24] = Vf[9 ]*hmf[3] + Vf[13]*hmf[4] + Vf[18]*hmf[5] + Vf[24]*hmf[6];
746 Vf[25] = Vf[13]*hmf[3] + Vf[14]*hmf[4] + Vf[19]*hmf[5] + Vf[25]*hmf[6];
747 Vf[26] = Vf[18]*hmf[3] + Vf[19]*hmf[4] + Vf[20]*hmf[5] + Vf[26]*hmf[6];
748 Vf[27] = Vf[24]*hmf[3] + Vf[25]*hmf[4] + Vf[26]*hmf[5] + (Vf24*hmf[3] + Vf25*hmf[4] + Vf26*hmf[5] + Vf[27]*hmf[6])*hmf[6]; //here Vf[] are already modified
749
750 mf[6] = E_mf;
751
752 //* find rf and Cf - optimum value of the measurement and its covariance matrix
753
754 //* mCCHt = C*H'
755 Double_t mCCHt0[6], mCCHt1[6], mCCHt2[6];
756
757 mCCHt0[0]=ffC[ 0]; mCCHt1[0]=ffC[ 1]; mCCHt2[0]=ffC[ 3];
758 mCCHt0[1]=ffC[ 1]; mCCHt1[1]=ffC[ 2]; mCCHt2[1]=ffC[ 4];
759 mCCHt0[2]=ffC[ 3]; mCCHt1[2]=ffC[ 4]; mCCHt2[2]=ffC[ 5];
760 mCCHt0[3]=ffC[ 6]; mCCHt1[3]=ffC[ 7]; mCCHt2[3]=ffC[ 8];
761 mCCHt0[4]=ffC[10]; mCCHt1[4]=ffC[11]; mCCHt2[4]=ffC[12];
762 mCCHt0[5]=ffC[15]; mCCHt1[5]=ffC[16]; mCCHt2[5]=ffC[17];
763
764 //* Kalman gain Krf = mCH'*S
765
766 Double_t krf0[6], krf1[6], krf2[6];
767
768 for(Int_t i=0;i<6;++i){
769 krf0[i] = mCCHt0[i]*mS[0] + mCCHt1[i]*mS[1] + mCCHt2[i]*mS[3];
770 krf1[i] = mCCHt0[i]*mS[1] + mCCHt1[i]*mS[2] + mCCHt2[i]*mS[4];
771 krf2[i] = mCCHt0[i]*mS[3] + mCCHt1[i]*mS[4] + mCCHt2[i]*mS[5];
772 }
773 Double_t rf[7] = { ffP[0], ffP[1], ffP[2], ffP[3], ffP[4], ffP[5], ffP[6] };
774
775 for(Int_t i=0;i<6;++i)
776 rf[i] = rf[i] + krf0[i]*zeta[0] + krf1[i]*zeta[1] + krf2[i]*zeta[2];
777
778 Double_t E_rf = TMath::Sqrt( Mass_rf2 + (rf[3]*rf[3] + rf[4]*rf[4] + rf[5]*rf[5]) );
779
780 Double_t Cf[28];
781 for(Int_t iC=0; iC<28; iC++)
782 Cf[iC] = ffC[iC];
783 //* hrf = d(Erf)/d(rf)
784 Double_t hrf[7];
121dc8bd 785 if( TMath::Abs(E_rf) < 1.e-10) hrf[3] = 0; else hrf[3] = rf[3]/E_rf;
786 if( TMath::Abs(E_rf) < 1.e-10) hrf[4] = 0; else hrf[4] = rf[4]/E_rf;
787 if( TMath::Abs(E_rf) < 1.e-10) hrf[5] = 0; else hrf[5] = rf[5]/E_rf;
788// if( TMath::Abs(E_rf) < 1.e-10) hrf[6] = 0; else hrf[6] = rf[6]/E_rf;
57ddc2cb 789 hrf[6] = 0;
790
791 for(Int_t i=0, k=0;i<6;++i){
792 for(Int_t j=0;j<=i;++j,++k){
793 Cf[k] = Cf[k] - (krf0[i]*mCCHt0[j] + krf1[i]*mCCHt1[j] + krf2[i]*mCCHt2[j] );
794 }
795 }
796 Double_t Cf24 = Cf[24], Cf25 = Cf[25], Cf26 = Cf[26];
797 Cf[21] = Cf[6 ]*hrf[3] + Cf[10]*hrf[4] + Cf[15]*hrf[5] + Cf[21]*hrf[6];
798 Cf[22] = Cf[7 ]*hrf[3] + Cf[11]*hrf[4] + Cf[16]*hrf[5] + Cf[22]*hrf[6];
799 Cf[23] = Cf[8 ]*hrf[3] + Cf[12]*hrf[4] + Cf[17]*hrf[5] + Cf[23]*hrf[6];
800 Cf[24] = Cf[9 ]*hrf[3] + Cf[13]*hrf[4] + Cf[18]*hrf[5] + Cf[24]*hrf[6];
801 Cf[25] = Cf[13]*hrf[3] + Cf[14]*hrf[4] + Cf[19]*hrf[5] + Cf[25]*hrf[6];
802 Cf[26] = Cf[18]*hrf[3] + Cf[19]*hrf[4] + Cf[20]*hrf[5] + Cf[26]*hrf[6];
803 Cf[27] = Cf[24]*hrf[3] + Cf[25]*hrf[4] + Cf[26]*hrf[5] + (Cf24*hrf[3] + Cf25*hrf[4] + Cf26*hrf[5] + Cf[27]*hrf[6])*hrf[6]; //here Cf[] are already modified
804
805 for(Int_t iC=21; iC<28; iC++)
806 {
807 ffC[iC] = Cf[iC];
808 mV[iC] = Vf[iC];
809 }
810
811 fP[6] = E_rf + E_mf;
812 rf[6] = E_rf;
813
814 //Double_t Dvv[3][3]; do not need this
815 Double_t Dvp[3][3];
816 Double_t Dpv[3][3];
817 Double_t Dpp[3][3];
818 Double_t De[7];
819
820 for(int i=0; i<3; i++)
821 {
822 for(int j=0; j<3; j++)
823 {
824 Dvp[i][j] = km0[i+3]*mCCHt0[j] + km1[i+3]*mCCHt1[j] + km2[i+3]*mCCHt2[j];
825 Dpv[i][j] = km0[i]*mCCHt0[j+3] + km1[i]*mCCHt1[j+3] + km2[i]*mCCHt2[j+3];
826 Dpp[i][j] = km0[i+3]*mCCHt0[j+3] + km1[i+3]*mCCHt1[j+3] + km2[i+3]*mCCHt2[j+3];
827 }
828 }
829
830 De[0] = hmf[3]*Dvp[0][0] + hmf[4]*Dvp[1][0] + hmf[5]*Dvp[2][0];
831 De[1] = hmf[3]*Dvp[0][1] + hmf[4]*Dvp[1][1] + hmf[5]*Dvp[2][1];
832 De[2] = hmf[3]*Dvp[0][2] + hmf[4]*Dvp[1][2] + hmf[5]*Dvp[2][2];
833 De[3] = hmf[3]*Dpp[0][0] + hmf[4]*Dpp[1][0] + hmf[5]*Dpp[2][0];
834 De[4] = hmf[3]*Dpp[0][1] + hmf[4]*Dpp[1][1] + hmf[5]*Dpp[2][1];
835 De[5] = hmf[3]*Dpp[0][2] + hmf[4]*Dpp[1][2] + hmf[5]*Dpp[2][2];
836 De[6] = 2*(De[3]*hrf[3] + De[4]*hrf[4] + De[5]*hrf[5]);
837
838 // last itearation -> update the particle
839
840 //* Add the daughter momentum to the particle momentum
841
842 ffP[ 3] += m[ 3];
843 ffP[ 4] += m[ 4];
844 ffP[ 5] += m[ 5];
845
846 ffC[ 9] += mV[ 9];
847 ffC[13] += mV[13];
848 ffC[14] += mV[14];
849 ffC[18] += mV[18];
850 ffC[19] += mV[19];
851 ffC[20] += mV[20];
852 ffC[24] += mV[24];
853 ffC[25] += mV[25];
854 ffC[26] += mV[26];
855 ffC[27] += mV[27];
856
857 ffC[21] += De[0];
858 ffC[22] += De[1];
859 ffC[23] += De[2];
860 ffC[24] += De[3];
861 ffC[25] += De[4];
862 ffC[26] += De[5];
863 ffC[27] += De[6];
864
865 //* New estimation of the vertex position r += K*zeta
866
867 for(Int_t i=0;i<6;++i)
868 fP[i] = ffP[i] + k0[i]*zeta[0] + k1[i]*zeta[1] + k2[i]*zeta[2];
869
870 //* New covariance matrix C -= K*(mCH')'
871
872 for(Int_t i=0, k=0;i<6;++i){
873 for(Int_t j=0;j<=i;++j,++k){
874 fC[k] = ffC[k] - (k0[i]*mCHt0[j] + k1[i]*mCHt1[j] + k2[i]*mCHt2[j] );
875 }
876 }
877
878 for(int i=21; i<28; i++) fC[i] = ffC[i];
879
880 //* Calculate Chi^2
881
882 fNDF += 2;
883 fQ += Daughter.GetQ();
884 fSFromDecay = 0;
885 fChi2 += (mS[0]*zeta[0] + mS[1]*zeta[1] + mS[3]*zeta[2])*zeta[0]
886 + (mS[1]*zeta[0] + mS[2]*zeta[1] + mS[4]*zeta[2])*zeta[1]
887 + (mS[3]*zeta[0] + mS[4]*zeta[1] + mS[5]*zeta[2])*zeta[2];
888 }
889}
890
891void AliKFParticleBase::AddDaughterWithEnergyFitMC( const AliKFParticleBase &Daughter )
892{
893 //* Energy considered as an independent variable, fitted independently from momentum, without any constraints on mass
894
895 //* Add daughter
896
897 TransportToDecayVertex();
898
899 Double_t b[3];
900 Int_t maxIter = 1;
901
902 if( !fIsLinearized ){
903 if( fNDF==-1 ){
904 Double_t ds, ds1;
905 GetDStoParticle(Daughter, ds, ds1);
906 TransportToDS( ds );
907 Double_t m[8];
908 Double_t mCd[36];
909 Daughter.Transport( ds1, m, mCd );
910 fVtxGuess[0] = .5*( fP[0] + m[0] );
911 fVtxGuess[1] = .5*( fP[1] + m[1] );
912 fVtxGuess[2] = .5*( fP[2] + m[2] );
913 } else {
914 fVtxGuess[0] = fP[0];
915 fVtxGuess[1] = fP[1];
916 fVtxGuess[2] = fP[2];
917 }
918 maxIter = 3;
919 }
920
921 for( Int_t iter=0; iter<maxIter; iter++ ){
922
923 {
924 GetFieldValue( fVtxGuess, b );
925 const Double_t kCLight = 0.000299792458;
926 b[0]*=kCLight; b[1]*=kCLight; b[2]*=kCLight;
927 }
928
929 Double_t *ffP = fP, *ffC = fC, tmpP[8], tmpC[36];
930 if( fNDF==-1 ){
931 GetMeasurement( fVtxGuess, tmpP, tmpC );
932 ffP = tmpP;
933 ffC = tmpC;
934 }
935 Double_t m[8], mV[36];
936
937 if( Daughter.fC[35]>0 ){
938 Daughter.GetMeasurement( fVtxGuess, m, mV );
939 } else {
940 for( Int_t i=0; i<8; i++ ) m[i] = Daughter.fP[i];
941 for( Int_t i=0; i<36; i++ ) mV[i] = Daughter.fC[i];
942 }
943 //*
944
945 Double_t mS[6];
946 {
947 Double_t mSi[6] = { ffC[0]+mV[0],
948 ffC[1]+mV[1], ffC[2]+mV[2],
949 ffC[3]+mV[3], ffC[4]+mV[4], ffC[5]+mV[5] };
950
951 mS[0] = mSi[2]*mSi[5] - mSi[4]*mSi[4];
952 mS[1] = mSi[3]*mSi[4] - mSi[1]*mSi[5];
953 mS[2] = mSi[0]*mSi[5] - mSi[3]*mSi[3];
954 mS[3] = mSi[1]*mSi[4] - mSi[2]*mSi[3];
955 mS[4] = mSi[1]*mSi[3] - mSi[0]*mSi[4];
956 mS[5] = mSi[0]*mSi[2] - mSi[1]*mSi[1];
957
958 Double_t s = ( mSi[0]*mS[0] + mSi[1]*mS[1] + mSi[3]*mS[3] );
959
960 s = ( s > 1.E-20 ) ?1./s :0;
961 mS[0]*=s;
962 mS[1]*=s;
963 mS[2]*=s;
964 mS[3]*=s;
965 mS[4]*=s;
966 mS[5]*=s;
967 }
968 //* Residual (measured - estimated)
969
970 Double_t zeta[3] = { m[0]-ffP[0], m[1]-ffP[1], m[2]-ffP[2] };
971
972
973 //* CHt = CH'
974
975 Double_t mCHt0[7], mCHt1[7], mCHt2[7];
976
977 mCHt0[0]=ffC[ 0] ; mCHt1[0]=ffC[ 1] ; mCHt2[0]=ffC[ 3] ;
978 mCHt0[1]=ffC[ 1] ; mCHt1[1]=ffC[ 2] ; mCHt2[1]=ffC[ 4] ;
979 mCHt0[2]=ffC[ 3] ; mCHt1[2]=ffC[ 4] ; mCHt2[2]=ffC[ 5] ;
980 mCHt0[3]=ffC[ 6] ; mCHt1[3]=ffC[ 7] ; mCHt2[3]=ffC[ 8] ;
981 mCHt0[4]=ffC[10] ; mCHt1[4]=ffC[11] ; mCHt2[4]=ffC[12] ;
982 mCHt0[5]=ffC[15] ; mCHt1[5]=ffC[16] ; mCHt2[5]=ffC[17] ;
983 mCHt0[6]=ffC[21] ; mCHt1[6]=ffC[22] ; mCHt2[6]=ffC[23] ;
984
985 //* Kalman gain K = mCH'*S
986
987 Double_t k0[7], k1[7], k2[7];
988
989 for(Int_t i=0;i<7;++i){
990 k0[i] = mCHt0[i]*mS[0] + mCHt1[i]*mS[1] + mCHt2[i]*mS[3];
991 k1[i] = mCHt0[i]*mS[1] + mCHt1[i]*mS[2] + mCHt2[i]*mS[4];
992 k2[i] = mCHt0[i]*mS[3] + mCHt1[i]*mS[4] + mCHt2[i]*mS[5];
993 }
994
995 //* New estimation of the vertex position
996
997 if( iter<maxIter-1 ){
998 for(Int_t i=0; i<3; ++i)
999 fVtxGuess[i]= ffP[i] + k0[i]*zeta[0]+k1[i]*zeta[1]+k2[i]*zeta[2];
1000 continue;
1001 }
1002
1003 // last itearation -> update the particle
1004
1005 //* VHt = VH'
1006
1007 Double_t mVHt0[7], mVHt1[7], mVHt2[7];
1008
1009 mVHt0[0]=mV[ 0] ; mVHt1[0]=mV[ 1] ; mVHt2[0]=mV[ 3] ;
1010 mVHt0[1]=mV[ 1] ; mVHt1[1]=mV[ 2] ; mVHt2[1]=mV[ 4] ;
1011 mVHt0[2]=mV[ 3] ; mVHt1[2]=mV[ 4] ; mVHt2[2]=mV[ 5] ;
1012 mVHt0[3]=mV[ 6] ; mVHt1[3]=mV[ 7] ; mVHt2[3]=mV[ 8] ;
1013 mVHt0[4]=mV[10] ; mVHt1[4]=mV[11] ; mVHt2[4]=mV[12] ;
1014 mVHt0[5]=mV[15] ; mVHt1[5]=mV[16] ; mVHt2[5]=mV[17] ;
1015 mVHt0[6]=mV[21] ; mVHt1[6]=mV[22] ; mVHt2[6]=mV[23] ;
1016
1017 //* Kalman gain Km = mCH'*S
1018
1019 Double_t km0[7], km1[7], km2[7];
1020
1021 for(Int_t i=0;i<7;++i){
1022 km0[i] = mVHt0[i]*mS[0] + mVHt1[i]*mS[1] + mVHt2[i]*mS[3];
1023 km1[i] = mVHt0[i]*mS[1] + mVHt1[i]*mS[2] + mVHt2[i]*mS[4];
1024 km2[i] = mVHt0[i]*mS[3] + mVHt1[i]*mS[4] + mVHt2[i]*mS[5];
1025 }
1026
1027 for(Int_t i=0;i<7;++i)
1028 ffP[i] = ffP[i] + k0[i]*zeta[0] + k1[i]*zeta[1] + k2[i]*zeta[2];
1029
1030 for(Int_t i=0;i<7;++i)
1031 m[i] = m[i] - km0[i]*zeta[0] - km1[i]*zeta[1] - km2[i]*zeta[2];
1032
1033 for(Int_t i=0, k=0;i<7;++i){
1034 for(Int_t j=0;j<=i;++j,++k){
1035 ffC[k] = ffC[k] - (k0[i]*mCHt0[j] + k1[i]*mCHt1[j] + k2[i]*mCHt2[j] );
1036 }
1037 }
1038
1039 for(Int_t i=0, k=0;i<7;++i){
1040 for(Int_t j=0;j<=i;++j,++k){
1041 mV[k] = mV[k] - (km0[i]*mVHt0[j] + km1[i]*mVHt1[j] + km2[i]*mVHt2[j] );
1042 }
1043 }
1044
1045 Double_t Df[7][7];
1046
1047 for(Int_t i=0;i<7;++i){
1048 for(Int_t j=0;j<7;++j){
1049 Df[i][j] = (km0[i]*mCHt0[j] + km1[i]*mCHt1[j] + km2[i]*mCHt2[j] );
1050 }
1051 }
1052
1053 Double_t J1[7][7], J2[7][7];
1054 for(Int_t iPar1=0; iPar1<7; iPar1++)
1055 {
1056 for(Int_t iPar2=0; iPar2<7; iPar2++)
1057 {
1058 J1[iPar1][iPar2] = 0;
1059 J2[iPar1][iPar2] = 0;
1060 }
1061 }
1062
1063 Double_t mMassParticle = ffP[6]*ffP[6] - (ffP[3]*ffP[3] + ffP[4]*ffP[4] + ffP[5]*ffP[5]);
1064 Double_t mMassDaughter = m[6]*m[6] - (m[3]*m[3] + m[4]*m[4] + m[5]*m[5]);
1065 if(mMassParticle > 0) mMassParticle = TMath::Sqrt(mMassParticle);
1066 if(mMassDaughter > 0) mMassDaughter = TMath::Sqrt(mMassDaughter);
1067
1068 if( fMassHypo > -0.5)
1069 SetMassConstraint(ffP,ffC,J1,fMassHypo);
1070 else if((mMassParticle < SumDaughterMass) || (ffP[6]<0) )
1071 SetMassConstraint(ffP,ffC,J1,SumDaughterMass);
1072
1073 if(Daughter.fMassHypo > -0.5)
1074 SetMassConstraint(m,mV,J2,Daughter.fMassHypo);
1075 else if((mMassDaughter < Daughter.SumDaughterMass) || (m[6] < 0) )
1076 SetMassConstraint(m,mV,J2,Daughter.SumDaughterMass);
1077
1078 Double_t DJ[7][7];
1079
1080 for(Int_t i=0; i<7; i++) {
1081 for(Int_t j=0; j<7; j++) {
1082 DJ[i][j] = 0;
1083 for(Int_t k=0; k<7; k++) {
1084 DJ[i][j] += Df[i][k]*J1[j][k];
1085 }
1086 }
1087 }
1088
1089 for(Int_t i=0; i<7; ++i){
1090 for(Int_t j=0; j<7; ++j){
1091 Df[i][j]=0;
1092 for(Int_t l=0; l<7; l++){
1093 Df[i][j] += J2[i][l]*DJ[l][j];
1094 }
1095 }
1096 }
1097
1098 //* Add the daughter momentum to the particle momentum
1099
1100 ffP[ 3] += m[ 3];
1101 ffP[ 4] += m[ 4];
1102 ffP[ 5] += m[ 5];
1103 ffP[ 6] += m[ 6];
1104
1105 ffC[ 9] += mV[ 9];
1106 ffC[13] += mV[13];
1107 ffC[14] += mV[14];
1108 ffC[18] += mV[18];
1109 ffC[19] += mV[19];
1110 ffC[20] += mV[20];
1111 ffC[24] += mV[24];
1112 ffC[25] += mV[25];
1113 ffC[26] += mV[26];
1114 ffC[27] += mV[27];
1115
1116 ffC[6 ] += Df[3][0]; ffC[7 ] += Df[3][1]; ffC[8 ] += Df[3][2];
1117 ffC[10] += Df[4][0]; ffC[11] += Df[4][1]; ffC[12] += Df[4][2];
1118 ffC[15] += Df[5][0]; ffC[16] += Df[5][1]; ffC[17] += Df[5][2];
1119 ffC[21] += Df[6][0]; ffC[22] += Df[6][1]; ffC[23] += Df[6][2];
1120
1121 ffC[9 ] += Df[3][3] + Df[3][3];
1122 ffC[13] += Df[4][3] + Df[3][4]; ffC[14] += Df[4][4] + Df[4][4];
1123 ffC[18] += Df[5][3] + Df[3][5]; ffC[19] += Df[5][4] + Df[4][5]; ffC[20] += Df[5][5] + Df[5][5];
1124 ffC[24] += Df[6][3] + Df[3][6]; ffC[25] += Df[6][4] + Df[4][6]; ffC[26] += Df[6][5] + Df[5][6]; ffC[27] += Df[6][6] + Df[6][6];
1125
1126 //* New estimation of the vertex position r += K*zeta
1127
1128 for(Int_t i=0;i<7;++i)
1129 fP[i] = ffP[i];
1130
1131 //* New covariance matrix C -= K*(mCH')'
1132
1133 for(Int_t i=0, k=0;i<7;++i){
1134 for(Int_t j=0;j<=i;++j,++k){
1135 fC[k] = ffC[k];
1136 }
1137 }
1138 //* Calculate Chi^2
1139
1140 fNDF += 2;
1141 fQ += Daughter.GetQ();
1142 fSFromDecay = 0;
1143 fChi2 += (mS[0]*zeta[0] + mS[1]*zeta[1] + mS[3]*zeta[2])*zeta[0]
1144 + (mS[1]*zeta[0] + mS[2]*zeta[1] + mS[4]*zeta[2])*zeta[1]
1145 + (mS[3]*zeta[0] + mS[4]*zeta[1] + mS[5]*zeta[2])*zeta[2];
1146 }
1147}
1148
f826d409 1149void AliKFParticleBase::SetProductionVertex( const AliKFParticleBase &Vtx )
1150{
706952f5 1151 //* Set production vertex for the particle, when the particle was not used in the vertex fit
f826d409 1152
1153 const Double_t *m = Vtx.fP, *mV = Vtx.fC;
1154
e7b09c95 1155 Bool_t noS = ( fC[35]<=0 ); // no decay length allowed
1156
1157 if( noS ){
1158 TransportToDecayVertex();
1159 fP[7] = 0;
55ac3e1e 1160 fC[28] = fC[29] = fC[30] = fC[31] = fC[32] = fC[33] = fC[34] = fC[35] = 0;
e7b09c95 1161 } else {
55ac3e1e 1162 TransportToDS( GetDStoPoint( m ) );
e7b09c95 1163 fP[7] = -fSFromDecay;
55ac3e1e 1164 fC[28] = fC[29] = fC[30] = fC[31] = fC[32] = fC[33] = fC[34] = 0;
0d76e8c6 1165 fC[35] = 0.1;
55ac3e1e 1166
e7b09c95 1167 Convert(1);
1168 }
1169
f826d409 1170 Double_t mAi[6];
706952f5 1171
446ce366 1172 InvertSym3( fC, mAi );
f826d409 1173
1174 Double_t mB[5][3];
1175
1176 mB[0][0] = fC[ 6]*mAi[0] + fC[ 7]*mAi[1] + fC[ 8]*mAi[3];
1177 mB[0][1] = fC[ 6]*mAi[1] + fC[ 7]*mAi[2] + fC[ 8]*mAi[4];
1178 mB[0][2] = fC[ 6]*mAi[3] + fC[ 7]*mAi[4] + fC[ 8]*mAi[5];
1179
1180 mB[1][0] = fC[10]*mAi[0] + fC[11]*mAi[1] + fC[12]*mAi[3];
1181 mB[1][1] = fC[10]*mAi[1] + fC[11]*mAi[2] + fC[12]*mAi[4];
1182 mB[1][2] = fC[10]*mAi[3] + fC[11]*mAi[4] + fC[12]*mAi[5];
1183
1184 mB[2][0] = fC[15]*mAi[0] + fC[16]*mAi[1] + fC[17]*mAi[3];
1185 mB[2][1] = fC[15]*mAi[1] + fC[16]*mAi[2] + fC[17]*mAi[4];
1186 mB[2][2] = fC[15]*mAi[3] + fC[16]*mAi[4] + fC[17]*mAi[5];
1187
1188 mB[3][0] = fC[21]*mAi[0] + fC[22]*mAi[1] + fC[23]*mAi[3];
1189 mB[3][1] = fC[21]*mAi[1] + fC[22]*mAi[2] + fC[23]*mAi[4];
1190 mB[3][2] = fC[21]*mAi[3] + fC[22]*mAi[4] + fC[23]*mAi[5];
1191
1192 mB[4][0] = fC[28]*mAi[0] + fC[29]*mAi[1] + fC[30]*mAi[3];
1193 mB[4][1] = fC[28]*mAi[1] + fC[29]*mAi[2] + fC[30]*mAi[4];
1194 mB[4][2] = fC[28]*mAi[3] + fC[29]*mAi[4] + fC[30]*mAi[5];
1195
1196 Double_t z[3] = { m[0]-fP[0], m[1]-fP[1], m[2]-fP[2] };
1197
1198 {
a65041d0 1199 Double_t mAVi[6] = { fC[0]-mV[0], fC[1]-mV[1], fC[2]-mV[2],
f826d409 1200 fC[3]-mV[3], fC[4]-mV[4], fC[5]-mV[5] };
706952f5 1201
a65041d0 1202 if( !InvertSym3( mAVi, mAVi ) ){
706952f5 1203
1204 Double_t dChi2 = ( +(mAVi[0]*z[0] + mAVi[1]*z[1] + mAVi[3]*z[2])*z[0]
1205 +(mAVi[1]*z[0] + mAVi[2]*z[1] + mAVi[4]*z[2])*z[1]
a65041d0 1206 +(mAVi[3]*z[0] + mAVi[4]*z[1] + mAVi[5]*z[2])*z[2] );
706952f5 1207
1208 // Take Abs(dChi2) here. Negative value of 'det' or 'dChi2' shows that the particle
1209 // was not used in the production vertex fit
1210
1211 fChi2+= TMath::Abs( dChi2 );
1212 }
f826d409 1213 fNDF += 2;
f826d409 1214 }
1215
1216 fP[0] = m[0];
1217 fP[1] = m[1];
1218 fP[2] = m[2];
1219 fP[3]+= mB[0][0]*z[0] + mB[0][1]*z[1] + mB[0][2]*z[2];
1220 fP[4]+= mB[1][0]*z[0] + mB[1][1]*z[1] + mB[1][2]*z[2];
1221 fP[5]+= mB[2][0]*z[0] + mB[2][1]*z[1] + mB[2][2]*z[2];
1222 fP[6]+= mB[3][0]*z[0] + mB[3][1]*z[1] + mB[3][2]*z[2];
1223 fP[7]+= mB[4][0]*z[0] + mB[4][1]*z[1] + mB[4][2]*z[2];
1224
1225 Double_t d0, d1, d2;
1226
1227 fC[0] = mV[0];
1228 fC[1] = mV[1];
1229 fC[2] = mV[2];
1230 fC[3] = mV[3];
1231 fC[4] = mV[4];
1232 fC[5] = mV[5];
1233
1234 d0= mB[0][0]*mV[0] + mB[0][1]*mV[1] + mB[0][2]*mV[3] - fC[ 6];
1235 d1= mB[0][0]*mV[1] + mB[0][1]*mV[2] + mB[0][2]*mV[4] - fC[ 7];
1236 d2= mB[0][0]*mV[3] + mB[0][1]*mV[4] + mB[0][2]*mV[5] - fC[ 8];
1237
1238 fC[ 6]+= d0;
1239 fC[ 7]+= d1;
1240 fC[ 8]+= d2;
1241 fC[ 9]+= d0*mB[0][0] + d1*mB[0][1] + d2*mB[0][2];
1242
1243 d0= mB[1][0]*mV[0] + mB[1][1]*mV[1] + mB[1][2]*mV[3] - fC[10];
1244 d1= mB[1][0]*mV[1] + mB[1][1]*mV[2] + mB[1][2]*mV[4] - fC[11];
1245 d2= mB[1][0]*mV[3] + mB[1][1]*mV[4] + mB[1][2]*mV[5] - fC[12];
1246
1247 fC[10]+= d0;
1248 fC[11]+= d1;
1249 fC[12]+= d2;
1250 fC[13]+= d0*mB[0][0] + d1*mB[0][1] + d2*mB[0][2];
1251 fC[14]+= d0*mB[1][0] + d1*mB[1][1] + d2*mB[1][2];
1252
1253 d0= mB[2][0]*mV[0] + mB[2][1]*mV[1] + mB[2][2]*mV[3] - fC[15];
1254 d1= mB[2][0]*mV[1] + mB[2][1]*mV[2] + mB[2][2]*mV[4] - fC[16];
1255 d2= mB[2][0]*mV[3] + mB[2][1]*mV[4] + mB[2][2]*mV[5] - fC[17];
1256
1257 fC[15]+= d0;
1258 fC[16]+= d1;
1259 fC[17]+= d2;
1260 fC[18]+= d0*mB[0][0] + d1*mB[0][1] + d2*mB[0][2];
1261 fC[19]+= d0*mB[1][0] + d1*mB[1][1] + d2*mB[1][2];
1262 fC[20]+= d0*mB[2][0] + d1*mB[2][1] + d2*mB[2][2];
1263
1264 d0= mB[3][0]*mV[0] + mB[3][1]*mV[1] + mB[3][2]*mV[3] - fC[21];
1265 d1= mB[3][0]*mV[1] + mB[3][1]*mV[2] + mB[3][2]*mV[4] - fC[22];
1266 d2= mB[3][0]*mV[3] + mB[3][1]*mV[4] + mB[3][2]*mV[5] - fC[23];
1267
1268 fC[21]+= d0;
1269 fC[22]+= d1;
1270 fC[23]+= d2;
1271 fC[24]+= d0*mB[0][0] + d1*mB[0][1] + d2*mB[0][2];
1272 fC[25]+= d0*mB[1][0] + d1*mB[1][1] + d2*mB[1][2];
1273 fC[26]+= d0*mB[2][0] + d1*mB[2][1] + d2*mB[2][2];
1274 fC[27]+= d0*mB[3][0] + d1*mB[3][1] + d2*mB[3][2];
1275
1276 d0= mB[4][0]*mV[0] + mB[4][1]*mV[1] + mB[4][2]*mV[3] - fC[28];
1277 d1= mB[4][0]*mV[1] + mB[4][1]*mV[2] + mB[4][2]*mV[4] - fC[29];
1278 d2= mB[4][0]*mV[3] + mB[4][1]*mV[4] + mB[4][2]*mV[5] - fC[30];
1279
1280 fC[28]+= d0;
1281 fC[29]+= d1;
1282 fC[30]+= d2;
1283 fC[31]+= d0*mB[0][0] + d1*mB[0][1] + d2*mB[0][2];
1284 fC[32]+= d0*mB[1][0] + d1*mB[1][1] + d2*mB[1][2];
1285 fC[33]+= d0*mB[2][0] + d1*mB[2][1] + d2*mB[2][2];
1286 fC[34]+= d0*mB[3][0] + d1*mB[3][1] + d2*mB[3][2];
1287 fC[35]+= d0*mB[4][0] + d1*mB[4][1] + d2*mB[4][2];
1288
e7b09c95 1289 if( noS ){
1290 fP[7] = 0;
55ac3e1e 1291 fC[28] = fC[29] = fC[30] = fC[31] = fC[32] = fC[33] = fC[34] = fC[35] = 0;
e7b09c95 1292 } else {
1293 TransportToDS( fP[7] );
1294 Convert(0);
1295 }
1296
f826d409 1297 fSFromDecay = 0;
f826d409 1298}
1299
57ddc2cb 1300void AliKFParticleBase::SetMassConstraint( Double_t *mP, Double_t *mC, Double_t J[7][7], Double_t Mass )
1301{
1302 const Double_t E2 = mP[6]*mP[6], p2 = mP[3]*mP[3]+mP[4]*mP[4]+mP[5]*mP[5], M2 = Mass*Mass;
1303
1304 const Double_t a = E2 - p2 + 2.*M2;
1305 const Double_t b = -2.*(E2 + p2);
1306 const Double_t c = E2 - p2 - M2;
1307
1308 Double_t Lambda = 0;
121dc8bd 1309 if(TMath::Abs(b) > 1.e-10) Lambda = -c / b;
57ddc2cb 1310
1311 Double_t D = 4.*E2*p2 - M2*(E2-p2-2.*M2);
121dc8bd 1312 if(D>=0 && TMath::Abs(a) > 1.e-10) Lambda = (E2 + p2 - sqrt(D))/a;
57ddc2cb 1313
1314 if(mP[6] < 0) //If energy < 0 we need a Lambda < 0
1315 Lambda = -1000000.; //Empirical, a better solution should be found
1316
1317 Int_t iIter=0;
1318 for(iIter=0; iIter<100; iIter++)
1319 {
1320 Double_t Lambda2 = Lambda*Lambda;
1321 Double_t Lambda4 = Lambda2*Lambda2;
1322
1323 Double_t Lambda0 = Lambda;
f826d409 1324
57ddc2cb 1325 Double_t f = -M2 * Lambda4 + a*Lambda2 + b*Lambda + c;
1326 Double_t df = -4.*M2 * Lambda2*Lambda + 2.*a*Lambda + b;
121dc8bd 1327 if(TMath::Abs(df) < 1.e-10) break;
57ddc2cb 1328 Lambda -= f/df;
121dc8bd 1329 if(TMath::Abs(Lambda0 - Lambda) < 1.e-8) break;
57ddc2cb 1330 }
1331
1332 const Double_t LPi = 1./(1. + Lambda);
1333 const Double_t LMi = 1./(1. - Lambda);
1334 const Double_t LP2i = LPi*LPi;
1335 const Double_t LM2i = LMi*LMi;
1336
1337 Double_t Lambda2 = Lambda*Lambda;
1338
1339 Double_t dfl = -4.*M2 * Lambda2*Lambda + 2.*a*Lambda + b;
1340 Double_t dfx[4] = {0,0,0,0};
1341 dfx[0] = -2.*(1. + Lambda)*(1. + Lambda)*mP[3];
1342 dfx[1] = -2.*(1. + Lambda)*(1. + Lambda)*mP[4];
1343 dfx[2] = -2.*(1. + Lambda)*(1. + Lambda)*mP[5];
1344 dfx[3] = 2.*(1. - Lambda)*(1. - Lambda)*mP[6];
1345 Double_t dlx[7] = {1,1,1,1,1,1,1};
121dc8bd 1346 if(TMath::Abs(dfl) > 1.e-10 )
57ddc2cb 1347 {
1348 for(int i=0; i<7; i++)
1349 dlx[i] = -dfx[i] / dfl;
1350 }
1351
1352 Double_t dxx[4] = {mP[3]*LM2i, mP[4]*LM2i, mP[5]*LM2i, -mP[6]*LP2i};
1353
1354 for(Int_t i=0; i<7; i++)
1355 for(Int_t j=0; j<7; j++)
1356 J[i][j]=0;
1357 J[0][0] = 1.;
1358 J[1][1] = 1.;
1359 J[2][2] = 1.;
1360
1361 for(Int_t i=3; i<7; i++)
1362 for(Int_t j=3; j<7; j++)
1363 J[i][j] = dlx[j-3]*dxx[i-3];
1364
1365 for(Int_t i=3; i<6; i++)
1366 J[i][i] += LMi;
1367 J[6][6] += LPi;
1368
1369 Double_t CJ[7][7];
1370
1371 for(Int_t i=0; i<7; i++) {
1372 for(Int_t j=0; j<7; j++) {
1373 CJ[i][j] = 0;
1374 for(Int_t k=0; k<7; k++) {
1375 CJ[i][j] += mC[IJ(i,k)]*J[j][k];
1376 }
1377 }
1378 }
1379
1380 for(Int_t i=0; i<7; ++i){
1381 for(Int_t j=0; j<=i; ++j){
1382 mC[IJ(i,j)]=0;
1383 for(Int_t l=0; l<7; l++){
1384 mC[IJ(i,j)] += J[i][l]*CJ[l][j];
1385 }
1386 }
1387 }
1388
1389 mP[3] *= LMi;
1390 mP[4] *= LMi;
1391 mP[5] *= LMi;
1392 mP[6] *= LPi;
1393}
1394
1395void AliKFParticleBase::SetNonlinearMassConstraint( Double_t Mass )
1396{
1397 Double_t J[7][7];
1398 SetMassConstraint( fP, fC, J, Mass );
1399 fMassHypo = Mass;
1400 SumDaughterMass = Mass;
1401}
f826d409 1402
e7b09c95 1403void AliKFParticleBase::SetMassConstraint( Double_t Mass, Double_t SigmaMass )
f826d409 1404{
706952f5 1405 //* Set hard( SigmaMass=0 ) or soft (SigmaMass>0) mass constraint
1406
57ddc2cb 1407 fMassHypo = Mass;
1408 SumDaughterMass = Mass;
1409
706952f5 1410 Double_t m2 = Mass*Mass; // measurement, weighted by Mass
1411 Double_t s2 = m2*SigmaMass*SigmaMass; // sigma^2
1412
1413 Double_t p2 = fP[3]*fP[3] + fP[4]*fP[4] + fP[5]*fP[5];
1414 Double_t e0 = TMath::Sqrt(m2+p2);
f826d409 1415
1416 Double_t mH[8];
1417 mH[0] = mH[1] = mH[2] = 0.;
1418 mH[3] = -2*fP[3];
1419 mH[4] = -2*fP[4];
1420 mH[5] = -2*fP[5];
706952f5 1421 mH[6] = 2*fP[6];//e0;
f826d409 1422 mH[7] = 0;
f826d409 1423
706952f5 1424 Double_t zeta = e0*e0 - e0*fP[6];
1425 zeta = m2 - (fP[6]*fP[6]-p2);
f826d409 1426
706952f5 1427 Double_t mCHt[8], s2_est=0;
1428 for( Int_t i=0; i<8; ++i ){
f826d409 1429 mCHt[i] = 0.0;
1430 for (Int_t j=0;j<8;++j) mCHt[i] += Cij(i,j)*mH[j];
706952f5 1431 s2_est += mH[i]*mCHt[i];
f826d409 1432 }
1433
706952f5 1434 if( s2_est<1.e-20 ) return; // calculated mass error is already 0,
1435 // the particle can not be constrained on mass
1436
1437 Double_t w2 = 1./( s2 + s2_est );
1438 fChi2 += zeta*zeta*w2;
f826d409 1439 fNDF += 1;
1440 for( Int_t i=0, ii=0; i<8; ++i ){
706952f5 1441 Double_t ki = mCHt[i]*w2;
f826d409 1442 fP[i]+= ki*zeta;
1443 for(Int_t j=0;j<=i;++j) fC[ii++] -= ki*mCHt[j];
1444 }
1445}
1446
1447
e7b09c95 1448void AliKFParticleBase::SetNoDecayLength()
1449{
1450 //* Set no decay length for resonances
1451
1452 TransportToDecayVertex();
1453
1454 Double_t h[8];
1455 h[0] = h[1] = h[2] = h[3] = h[4] = h[5] = h[6] = 0;
1456 h[7] = 1;
1457
1458 Double_t zeta = 0 - fP[7];
1459 for(Int_t i=0;i<8;++i) zeta -= h[i]*(fP[i]-fP[i]);
1460
1461 Double_t s = fC[35];
1462 if( s>1.e-20 ){
1463 s = 1./s;
1464 fChi2 += zeta*zeta*s;
1465 fNDF += 1;
1466 for( Int_t i=0, ii=0; i<7; ++i ){
1467 Double_t ki = fC[28+i]*s;
1468 fP[i]+= ki*zeta;
1469 for(Int_t j=0;j<=i;++j) fC[ii++] -= ki*fC[28+j];
1470 }
1471 }
1472 fP[7] = 0;
55ac3e1e 1473 fC[28] = fC[29] = fC[30] = fC[31] = fC[32] = fC[33] = fC[34] = fC[35] = 0;
e7b09c95 1474}
1475
1476
f826d409 1477void AliKFParticleBase::Construct( const AliKFParticleBase* vDaughters[], Int_t NDaughters,
706952f5 1478 const AliKFParticleBase *Parent, Double_t Mass, Bool_t IsConstrained )
f826d409 1479{
1480 //* Full reconstruction in one go
1481
1482 Int_t maxIter = 1;
1483 bool wasLinearized = fIsLinearized;
706952f5 1484 if( !fIsLinearized || IsConstrained ){
616ffc76 1485 //fVtxGuess[0] = fVtxGuess[1] = fVtxGuess[2] = 0; //!!!!
1486 fVtxGuess[0] = GetX();
1487 fVtxGuess[1] = GetY();
1488 fVtxGuess[2] = GetZ();
f826d409 1489 fIsLinearized = 1;
1490 maxIter = 3;
1491 }
1492
706952f5 1493 Double_t constraintC[6];
1494
1495 if( IsConstrained ){
1496 for(Int_t i=0;i<6;++i) constraintC[i]=fC[i];
1497 } else {
1498 for(Int_t i=0;i<6;++i) constraintC[i]=0.;
1499 constraintC[0] = constraintC[2] = constraintC[5] = 100.;
1500 }
1501
1502
f826d409 1503 for( Int_t iter=0; iter<maxIter; iter++ ){
f826d409 1504 fAtProductionVertex = 0;
1505 fSFromDecay = 0;
1506 fP[0] = fVtxGuess[0];
1507 fP[1] = fVtxGuess[1];
1508 fP[2] = fVtxGuess[2];
1509 fP[3] = 0;
1510 fP[4] = 0;
1511 fP[5] = 0;
1512 fP[6] = 0;
1513 fP[7] = 0;
57ddc2cb 1514 SumDaughterMass = 0;
1515
706952f5 1516 for(Int_t i=0;i<6; ++i) fC[i]=constraintC[i];
1517 for(Int_t i=6;i<36;++i) fC[i]=0.;
f826d409 1518 fC[35] = 1.;
57ddc2cb 1519
706952f5 1520 fNDF = IsConstrained ?0 :-3;
f826d409 1521 fChi2 = 0.;
1522 fQ = 0;
1523
4bbc290d 1524 for( Int_t itr =0; itr<NDaughters; itr++ ){
1525 AddDaughter( *vDaughters[itr] );
1526 }
f826d409 1527 if( iter<maxIter-1){
1528 for( Int_t i=0; i<3; i++ ) fVtxGuess[i] = fP[i];
1529 }
1530 }
1531 fIsLinearized = wasLinearized;
1532
1533 if( Mass>=0 ) SetMassConstraint( Mass );
1534 if( Parent ) SetProductionVertex( *Parent );
1535}
1536
1537
1538void AliKFParticleBase::Convert( bool ToProduction )
1539{
1540 //* Tricky function - convert the particle error along its trajectory to
1541 //* the value which corresponds to its production/decay vertex
1542 //* It is done by combination of the error of decay length with the position errors
1543
1544 Double_t fld[3];
1545 {
1546 GetFieldValue( fP, fld );
1547 const Double_t kCLight = fQ*0.000299792458;
1548 fld[0]*=kCLight; fld[1]*=kCLight; fld[2]*=kCLight;
1549 }
1550
1551 Double_t h[6];
1552
1553 h[0] = fP[3];
1554 h[1] = fP[4];
1555 h[2] = fP[5];
1556 if( ToProduction ){ h[0]=-h[0]; h[1]=-h[1]; h[2]=-h[2]; }
1557 h[3] = h[1]*fld[2]-h[2]*fld[1];
1558 h[4] = h[2]*fld[0]-h[0]*fld[2];
1559 h[5] = h[0]*fld[1]-h[1]*fld[0];
1560
1561 Double_t c;
1562
1563 c = fC[28]+h[0]*fC[35];
1564 fC[ 0]+= h[0]*(c+fC[28]);
1565 fC[28] = c;
1566
1567 fC[ 1]+= h[1]*fC[28] + h[0]*fC[29];
1568 c = fC[29]+h[1]*fC[35];
1569 fC[ 2]+= h[1]*(c+fC[29]);
1570 fC[29] = c;
1571
1572 fC[ 3]+= h[2]*fC[28] + h[0]*fC[30];
1573 fC[ 4]+= h[2]*fC[29] + h[1]*fC[30];
1574 c = fC[30]+h[2]*fC[35];
1575 fC[ 5]+= h[2]*(c+fC[30]);
1576 fC[30] = c;
1577
1578 fC[ 6]+= h[3]*fC[28] + h[0]*fC[31];
1579 fC[ 7]+= h[3]*fC[29] + h[1]*fC[31];
1580 fC[ 8]+= h[3]*fC[30] + h[2]*fC[31];
1581 c = fC[31]+h[3]*fC[35];
1582 fC[ 9]+= h[3]*(c+fC[31]);
1583 fC[31] = c;
1584
1585 fC[10]+= h[4]*fC[28] + h[0]*fC[32];
1586 fC[11]+= h[4]*fC[29] + h[1]*fC[32];
1587 fC[12]+= h[4]*fC[30] + h[2]*fC[32];
1588 fC[13]+= h[4]*fC[31] + h[3]*fC[32];
1589 c = fC[32]+h[4]*fC[35];
1590 fC[14]+= h[4]*(c+fC[32]);
1591 fC[32] = c;
1592
1593 fC[15]+= h[5]*fC[28] + h[0]*fC[33];
1594 fC[16]+= h[5]*fC[29] + h[1]*fC[33];
1595 fC[17]+= h[5]*fC[30] + h[2]*fC[33];
1596 fC[18]+= h[5]*fC[31] + h[3]*fC[33];
1597 fC[19]+= h[5]*fC[32] + h[4]*fC[33];
1598 c = fC[33]+h[5]*fC[35];
1599 fC[20]+= h[5]*(c+fC[33]);
1600 fC[33] = c;
1601
1602 fC[21]+= h[0]*fC[34];
1603 fC[22]+= h[1]*fC[34];
1604 fC[23]+= h[2]*fC[34];
1605 fC[24]+= h[3]*fC[34];
1606 fC[25]+= h[4]*fC[34];
1607 fC[26]+= h[5]*fC[34];
1608}
1609
1610
1611void AliKFParticleBase::TransportToDecayVertex()
1612{
1613 //* Transport the particle to its decay vertex
1614
1615 if( fSFromDecay != 0 ) TransportToDS( -fSFromDecay );
1616 if( fAtProductionVertex ) Convert(0);
1617 fAtProductionVertex = 0;
1618}
1619
1620void AliKFParticleBase::TransportToProductionVertex()
1621{
1622 //* Transport the particle to its production vertex
616ffc76 1623
f826d409 1624 if( fSFromDecay != -fP[7] ) TransportToDS( -fSFromDecay-fP[7] );
1625 if( !fAtProductionVertex ) Convert( 1 );
1626 fAtProductionVertex = 1;
1627}
1628
1629
1630void AliKFParticleBase::TransportToDS( Double_t dS )
1631{
1632 //* Transport the particle on dS parameter (SignedPath/Momentum)
616ffc76 1633
f826d409 1634 Transport( dS, fP, fC );
1635 fSFromDecay+= dS;
1636}
1637
1638
1639Double_t AliKFParticleBase::GetDStoPointLine( const Double_t xyz[] ) const
1640{
1641 //* Get dS to a certain space point without field
1642
1643 Double_t p2 = fP[3]*fP[3] + fP[4]*fP[4] + fP[5]*fP[5];
1644 if( p2<1.e-4 ) p2 = 1;
1645 return ( fP[3]*(xyz[0]-fP[0]) + fP[4]*(xyz[1]-fP[1]) + fP[5]*(xyz[2]-fP[2]) )/p2;
1646}
1647
1648
1649Double_t AliKFParticleBase::GetDStoPointBz( Double_t B, const Double_t xyz[] )
1650 const
1651{
616ffc76 1652
f826d409 1653 //* Get dS to a certain space point for Bz field
f826d409 1654 const Double_t kCLight = 0.000299792458;
1655 Double_t bq = B*fQ*kCLight;
1656 Double_t pt2 = fP[3]*fP[3] + fP[4]*fP[4];
1657 if( pt2<1.e-4 ) return 0;
1658 Double_t dx = xyz[0] - fP[0];
1659 Double_t dy = xyz[1] - fP[1];
1660 Double_t a = dx*fP[3]+dy*fP[4];
706952f5 1661 Double_t dS;
1662
1663 if( TMath::Abs(bq)<1.e-8 ) dS = a/pt2;
1664 else dS = TMath::ATan2( bq*a, pt2 + bq*(dy*fP[3] -dx*fP[4]) )/bq;
1665
1666 if(0){
1667
1668 Double_t px = fP[3];
1669 Double_t py = fP[4];
1670 Double_t pz = fP[5];
1671 Double_t ss[2], g[2][5];
1672
1673 ss[0] = dS;
1674 ss[1] = -dS;
1675 for( Int_t i=0; i<2; i++){
1676 Double_t bs = bq*ss[i];
1677 Double_t c = TMath::Cos(bs), s = TMath::Sin(bs);
1678 Double_t cB,sB;
1679 if( TMath::Abs(bq)>1.e-8){
1680 cB= (1-c)/bq;
1681 sB= s/bq;
1682 }else{
bfd20868 1683 const Double_t kOvSqr6 = 1./TMath::Sqrt(6.);
1684 sB = (1.-bs*kOvSqr6)*(1.+bs*kOvSqr6)*ss[i];
706952f5 1685 cB = .5*sB*bs;
1686 }
1687 g[i][0] = fP[0] + sB*px + cB*py;
1688 g[i][1] = fP[1] - cB*px + sB*py;
1689 g[i][2] = fP[2] + ss[i]*pz;
1690 g[i][3] = + c*px + s*py;
1691 g[i][4] = - s*px + c*py;
1692 }
1693
1694 Int_t i=0;
1695
1696 Double_t dMin = 1.e10;
1697 for( Int_t j=0; j<2; j++){
1698 Double_t xx = g[j][0]-xyz[0];
1699 Double_t yy = g[j][1]-xyz[1];
1700 Double_t zz = g[j][2]-xyz[2];
1701 Double_t d = xx*xx + yy*yy + zz*zz;
1702 if( d<dMin ){
1703 dMin = d;
1704 i = j;
1705 }
1706 }
1707
1708 dS = ss[i];
1709
1710 Double_t x= g[i][0], y= g[i][1], z= g[i][2], ppx= g[i][3], ppy= g[i][4];
5fc72f28 1711 Double_t ddx = x-xyz[0];
1712 Double_t ddy = y-xyz[1];
1713 Double_t ddz = z-xyz[2];
1714 Double_t c = ddx*ppx + ddy*ppy + ddz*pz ;
706952f5 1715 Double_t pp2 = ppx*ppx + ppy*ppy + pz*pz;
1716 if( TMath::Abs(pp2)>1.e-8 ){
1717 dS+=c/pp2;
1718 }
1719 }
1720 return dS;
f826d409 1721}
1722
1723
1724void AliKFParticleBase::GetDStoParticleBz( Double_t B, const AliKFParticleBase &p,
616ffc76 1725 Double_t &DS, Double_t &DS1 )
f826d409 1726 const
1727{
1728 //* Get dS to another particle for Bz field
f826d409 1729 Double_t px = fP[3];
1730 Double_t py = fP[4];
1731 Double_t pz = fP[5];
1732
1733 Double_t px1 = p.fP[3];
1734 Double_t py1 = p.fP[4];
1735 Double_t pz1 = p.fP[5];
1736
1737 const Double_t kCLight = 0.000299792458;
1738
1739 Double_t bq = B*fQ*kCLight;
1740 Double_t bq1 = B*p.fQ*kCLight;
f826d409 1741 Double_t s=0, ds=0, s1=0, ds1=0;
1742
1743 if( TMath::Abs(bq)>1.e-8 || TMath::Abs(bq1)>1.e-8 ){
4bbc290d 1744
f826d409 1745 Double_t dx = (p.fP[0] - fP[0]);
1746 Double_t dy = (p.fP[1] - fP[1]);
1747 Double_t d2 = (dx*dx+dy*dy);
1748
1749 Double_t p2 = (px *px + py *py);
1750 Double_t p21 = (px1*px1 + py1*py1);
1d96fee9 1751
1752 if( TMath::Abs(p2) < 1.e-8 || TMath::Abs(p21) < 1.e-8 )
1753 {
1754 DS=0.;
1755 DS1=0.;
1756 return;
1757 }
1758
f826d409 1759 Double_t a = (px*py1 - py*px1);
1760 Double_t b = (px*px1 + py*py1);
1761
1762 Double_t ldx = bq*bq1*dx - bq1*py + bq*py1 ;
1763 Double_t ldy = bq*bq1*dy + bq1*px - bq*px1 ;
1764 Double_t l2 = ldx*ldx + ldy*ldy;
1765
1766 Double_t cS = bq1*p2 + bq*bq1*(dy* px - dx* py) - bq*b;
1767 Double_t cS1= bq*p21 - bq*bq1*(dy*px1 - dx*py1) - bq1*b;
1768
1769 Double_t ca = bq*bq*bq1*d2 +2*( cS + bq*bq*(py1*dx-px1*dy)) ;
1770 Double_t ca1 = bq*bq1*bq1*d2 +2*( cS1 - bq1*bq1*(py*dx-px*dy)) ;
1771
1772 Double_t sa = 4*l2*p2 - ca*ca;
1773 Double_t sa1 = 4*l2*p21 - ca1*ca1;
e7b09c95 1774
f826d409 1775 if(sa<0) sa=0;
1776 if(sa1<0)sa1=0;
1777
1778 if( TMath::Abs(bq)>1.e-8){
1779 s = TMath::ATan2( bq*( bq1*(dx*px +dy*py) + a ) , cS )/bq;
1780 ds = TMath::ATan2(TMath::Sqrt(sa),ca)/bq;
1781 } else {
1782 s = ( (dx*px + dy*py) + (py*px1-px*py1)/bq1)/p2;
1783 ds = s*s - (d2-2*(px1*dy-py1*dx)/bq1)/p2;
1784 if( ds<0 ) ds = 0;
1785 ds = TMath::Sqrt(ds);
1786 }
1787
1788 if( TMath::Abs(bq1)>1.e-8){
1789 s1 = TMath::ATan2( -bq1*( bq*(dx*px1+dy*py1) + a), cS1 )/bq1;
1790 ds1 = TMath::ATan2(TMath::Sqrt(sa1),ca1)/bq1;
1791 } else {
1792 s1 = (-(dx*px1 + dy*py1) + (py*px1-px*py1)/bq)/p21;
1793 ds1 = s1*s1 - (d2+2*(px*dy-py*dx)/bq)/p21;
1794 if( ds1<0 ) ds1 = 0;
1795 ds1 = TMath::Sqrt(ds1);
1796 }
1797 }
1798
f826d409 1799 Double_t ss[2], ss1[2], g[2][5],g1[2][5];
1800
1801 ss[0] = s + ds;
1802 ss[1] = s - ds;
1803 ss1[0] = s1 + ds1;
1804 ss1[1] = s1 - ds1;
1805 for( Int_t i=0; i<2; i++){
1806 Double_t bs = bq*ss[i];
5fc72f28 1807 Double_t c = TMath::Cos(bs), sss = TMath::Sin(bs);
f826d409 1808 Double_t cB,sB;
1809 if( TMath::Abs(bq)>1.e-8){
1810 cB= (1-c)/bq;
5fc72f28 1811 sB= sss/bq;
f826d409 1812 }else{
bfd20868 1813 const Double_t kOvSqr6 = 1./TMath::Sqrt(6.);
1814 sB = (1.-bs*kOvSqr6)*(1.+bs*kOvSqr6)*ss[i];
f826d409 1815 cB = .5*sB*bs;
1816 }
1817 g[i][0] = fP[0] + sB*px + cB*py;
1818 g[i][1] = fP[1] - cB*px + sB*py;
1819 g[i][2] = fP[2] + ss[i]*pz;
5fc72f28 1820 g[i][3] = + c*px + sss*py;
1821 g[i][4] = - sss*px + c*py;
f826d409 1822
1823 bs = bq1*ss1[i];
5fc72f28 1824 c = TMath::Cos(bs); sss = TMath::Sin(bs);
f826d409 1825 if( TMath::Abs(bq1)>1.e-8){
1826 cB= (1-c)/bq1;
5fc72f28 1827 sB= sss/bq1;
f826d409 1828 }else{
bfd20868 1829 const Double_t kOvSqr6 = 1./TMath::Sqrt(6.);
1830 sB = (1.-bs*kOvSqr6)*(1.+bs*kOvSqr6)*ss1[i];
f826d409 1831 cB = .5*sB*bs;
1832 }
1833
e7b09c95 1834 g1[i][0] = p.fP[0] + sB*px1 + cB*py1;
1835 g1[i][1] = p.fP[1] - cB*px1 + sB*py1;
1836 g1[i][2] = p.fP[2] + ss[i]*pz1;
5fc72f28 1837 g1[i][3] = + c*px1 + sss*py1;
1838 g1[i][4] = - sss*px1 + c*py1;
f826d409 1839 }
1840
1841 Int_t i=0, i1=0;
1842
1843 Double_t dMin = 1.e10;
1844 for( Int_t j=0; j<2; j++){
1845 for( Int_t j1=0; j1<2; j1++){
1846 Double_t xx = g[j][0]-g1[j1][0];
1847 Double_t yy = g[j][1]-g1[j1][1];
1848 Double_t zz = g[j][2]-g1[j1][2];
1849 Double_t d = xx*xx + yy*yy + zz*zz;
1850 if( d<dMin ){
1851 dMin = d;
1852 i = j;
1853 i1 = j1;
1854 }
1855 }
1856 }
1857
1858 DS = ss[i];
1859 DS1 = ss1[i1];
91468b27 1860 if(0){
1861 Double_t x= g[i][0], y= g[i][1], z= g[i][2], ppx= g[i][3], ppy= g[i][4];
1862 Double_t x1=g1[i1][0], y1= g1[i1][1], z1= g1[i1][2], ppx1= g1[i1][3], ppy1= g1[i1][4];
1863 Double_t dx = x1-x;
1864 Double_t dy = y1-y;
1865 Double_t dz = z1-z;
1866 Double_t a = ppx*ppx1 + ppy*ppy1 + pz*pz1;
1867 Double_t b = dx*ppx1 + dy*ppy1 + dz*pz1;
1868 Double_t c = dx*ppx + dy*ppy + dz*pz ;
1869 Double_t pp2 = ppx*ppx + ppy*ppy + pz*pz;
1870 Double_t pp21= ppx1*ppx1 + ppy1*ppy1 + pz1*pz1;
706952f5 1871 Double_t det = pp2*pp21 - a*a;
91468b27 1872 if( TMath::Abs(det)>1.e-8 ){
1873 DS+=(a*b-pp21*c)/det;
1874 DS1+=(a*c-pp2*b)/det;
1875 }
f826d409 1876 }
1877}
1878
1879
1880
1881void AliKFParticleBase::TransportCBM( Double_t dS,
1882 Double_t P[], Double_t C[] ) const
1883{
1884 //* Transport the particle on dS, output to P[],C[], for CBM field
1885
1886 if( fQ==0 ){
1887 TransportLine( dS, P, C );
1888 return;
1889 }
1890
1891 const Double_t kCLight = 0.000299792458;
1892
1893 Double_t c = fQ*kCLight;
1894
1895 // construct coefficients
1896
1897 Double_t
1898 px = fP[3],
1899 py = fP[4],
1900 pz = fP[5];
1901
1902 Double_t sx=0, sy=0, sz=0, syy=0, syz=0, syyy=0, ssx=0, ssy=0, ssz=0, ssyy=0, ssyz=0, ssyyy=0;
1903
1904 { // get field integrals
1905
1906 Double_t fld[3][3];
1907 Double_t p0[3], p1[3], p2[3];
1908
1909 // line track approximation
1910
1911 p0[0] = fP[0];
1912 p0[1] = fP[1];
1913 p0[2] = fP[2];
1914
1915 p2[0] = fP[0] + px*dS;
1916 p2[1] = fP[1] + py*dS;
1917 p2[2] = fP[2] + pz*dS;
1918
1919 p1[0] = 0.5*(p0[0]+p2[0]);
1920 p1[1] = 0.5*(p0[1]+p2[1]);
1921 p1[2] = 0.5*(p0[2]+p2[2]);
1922
1923 // first order track approximation
1924 {
1925 GetFieldValue( p0, fld[0] );
1926 GetFieldValue( p1, fld[1] );
1927 GetFieldValue( p2, fld[2] );
1928
1929 Double_t ssy1 = ( 7*fld[0][1] + 6*fld[1][1]-fld[2][1] )*c*dS*dS/96.;
1930 Double_t ssy2 = ( fld[0][1] + 2*fld[1][1] )*c*dS*dS/6.;
1931
1932 p1[0] -= ssy1*pz;
1933 p1[2] += ssy1*px;
1934 p2[0] -= ssy2*pz;
1935 p2[2] += ssy2*px;
1936 }
1937
1938 GetFieldValue( p0, fld[0] );
1939 GetFieldValue( p1, fld[1] );
1940 GetFieldValue( p2, fld[2] );
1941
1942 sx = c*( fld[0][0] + 4*fld[1][0] + fld[2][0] )*dS/6.;
1943 sy = c*( fld[0][1] + 4*fld[1][1] + fld[2][1] )*dS/6.;
1944 sz = c*( fld[0][2] + 4*fld[1][2] + fld[2][2] )*dS/6.;
1945
1946 ssx = c*( fld[0][0] + 2*fld[1][0])*dS*dS/6.;
1947 ssy = c*( fld[0][1] + 2*fld[1][1])*dS*dS/6.;
1948 ssz = c*( fld[0][2] + 2*fld[1][2])*dS*dS/6.;
1949
1950 Double_t c2[3][3] = { { 5, -4, -1},{ 44, 80, -4},{ 11, 44, 5} }; // /=360.
1951 Double_t cc2[3][3] = { { 38, 8, -4},{ 148, 208, -20},{ 3, 36, 3} }; // /=2520.
1952 for(Int_t n=0; n<3; n++)
1953 for(Int_t m=0; m<3; m++)
1954 {
1955 syz += c2[n][m]*fld[n][1]*fld[m][2];
1956 ssyz += cc2[n][m]*fld[n][1]*fld[m][2];
1957 }
1958
1959 syz *= c*c*dS*dS/360.;
1960 ssyz *= c*c*dS*dS*dS/2520.;
1961
1962 syy = c*( fld[0][1] + 4*fld[1][1] + fld[2][1] )*dS;
1963 syyy = syy*syy*syy / 1296;
1964 syy = syy*syy/72;
1965
1966 ssyy = ( fld[0][1]*( 38*fld[0][1] + 156*fld[1][1] - fld[2][1] )+
1967 fld[1][1]*( 208*fld[1][1] +16*fld[2][1] )+
1968 fld[2][1]*( 3*fld[2][1] )
1969 )*dS*dS*dS*c*c/2520.;
1970 ssyyy =
1971 (
1972 fld[0][1]*( fld[0][1]*( 85*fld[0][1] + 526*fld[1][1] - 7*fld[2][1] )+
1973 fld[1][1]*( 1376*fld[1][1] +84*fld[2][1] )+
1974 fld[2][1]*( 19*fld[2][1] ) )+
1975 fld[1][1]*( fld[1][1]*( 1376*fld[1][1] +256*fld[2][1] )+
1976 fld[2][1]*( 62*fld[2][1] ) )+
1977 fld[2][1]*fld[2][1] *( 3*fld[2][1] )
1978 )*dS*dS*dS*dS*c*c*c/90720.;
1979
1980 }
1981
1982 Double_t mJ[8][8];
1983 for( Int_t i=0; i<8; i++ ) for( Int_t j=0; j<8; j++) mJ[i][j]=0;
1984
1985 mJ[0][0]=1; mJ[0][1]=0; mJ[0][2]=0; mJ[0][3]=dS-ssyy; mJ[0][4]=ssx; mJ[0][5]=ssyyy-ssy;
1986 mJ[1][0]=0; mJ[1][1]=1; mJ[1][2]=0; mJ[1][3]=-ssz; mJ[1][4]=dS; mJ[1][5]=ssx+ssyz;
1987 mJ[2][0]=0; mJ[2][1]=0; mJ[2][2]=1; mJ[2][3]=ssy-ssyyy; mJ[2][4]=-ssx; mJ[2][5]=dS-ssyy;
1988
1989 mJ[3][0]=0; mJ[3][1]=0; mJ[3][2]=0; mJ[3][3]=1-syy; mJ[3][4]=sx; mJ[3][5]=syyy-sy;
1990 mJ[4][0]=0; mJ[4][1]=0; mJ[4][2]=0; mJ[4][3]=-sz; mJ[4][4]=1; mJ[4][5]=sx+syz;
1991 mJ[5][0]=0; mJ[5][1]=0; mJ[5][2]=0; mJ[5][3]=sy-syyy; mJ[5][4]=-sx; mJ[5][5]=1-syy;
1992 mJ[6][6] = mJ[7][7] = 1;
1993
1994 P[0] = fP[0] + mJ[0][3]*px + mJ[0][4]*py + mJ[0][5]*pz;
1995 P[1] = fP[1] + mJ[1][3]*px + mJ[1][4]*py + mJ[1][5]*pz;
1996 P[2] = fP[2] + mJ[2][3]*px + mJ[2][4]*py + mJ[2][5]*pz;
1997 P[3] = mJ[3][3]*px + mJ[3][4]*py + mJ[3][5]*pz;
1998 P[4] = mJ[4][3]*px + mJ[4][4]*py + mJ[4][5]*pz;
1999 P[5] = mJ[5][3]*px + mJ[5][4]*py + mJ[5][5]*pz;
2000 P[6] = fP[6];
2001 P[7] = fP[7];
2002
2003 MultQSQt( mJ[0], fC, C);
2004
2005}
2006
2007
0d14829a 2008void AliKFParticleBase::TransportBz( Double_t b, Double_t t,
2009 Double_t p[], Double_t e[] ) const
f826d409 2010{
2011 //* Transport the particle on dS, output to P[],C[], for Bz field
616ffc76 2012
f826d409 2013 const Double_t kCLight = 0.000299792458;
5fc72f28 2014 b = b*fQ*kCLight;
0d14829a 2015 Double_t bs= b*t;
f826d409 2016 Double_t s = TMath::Sin(bs), c = TMath::Cos(bs);
2017 Double_t sB, cB;
616ffc76 2018 if( TMath::Abs(bs)>1.e-10){
5fc72f28 2019 sB= s/b;
2020 cB= (1-c)/b;
f826d409 2021 }else{
bfd20868 2022 const Double_t kOvSqr6 = 1./TMath::Sqrt(6.);
0d14829a 2023 sB = (1.-bs*kOvSqr6)*(1.+bs*kOvSqr6)*t;
f826d409 2024 cB = .5*sB*bs;
2025 }
2026
2027 Double_t px = fP[3];
2028 Double_t py = fP[4];
2029 Double_t pz = fP[5];
2030
5fc72f28 2031 p[0] = fP[0] + sB*px + cB*py;
2032 p[1] = fP[1] - cB*px + sB*py;
0d14829a 2033 p[2] = fP[2] + t*pz;
5fc72f28 2034 p[3] = c*px + s*py;
2035 p[4] = -s*px + c*py;
2036 p[5] = fP[5];
2037 p[6] = fP[6];
2038 p[7] = fP[7];
0d14829a 2039
2040 /*
f826d409 2041 Double_t mJ[8][8] = { {1,0,0, sB, cB, 0, 0, 0 },
616ffc76 2042 {0,1,0, -cB, sB, 0, 0, 0 },
0d14829a 2043 {0,0,1, 0, 0, t, 0, 0 },
616ffc76 2044 {0,0,0, c, s, 0, 0, 0 },
2045 {0,0,0, -s, c, 0, 0, 0 },
2046 {0,0,0, 0, 0, 1, 0, 0 },
2047 {0,0,0, 0, 0, 0, 1, 0 },
2048 {0,0,0, 0, 0, 0, 0, 1 } };
f826d409 2049 Double_t mA[8][8];
2050 for( Int_t k=0,i=0; i<8; i++)
2051 for( Int_t j=0; j<=i; j++, k++ ) mA[i][j] = mA[j][i] = fC[k];
2052
2053 Double_t mJC[8][8];
2054 for( Int_t i=0; i<8; i++ )
2055 for( Int_t j=0; j<8; j++ ){
2056 mJC[i][j]=0;
2057 for( Int_t k=0; k<8; k++ ) mJC[i][j]+=mJ[i][k]*mA[k][j];
2058 }
2059
2060 for( Int_t k=0,i=0; i<8; i++)
2061 for( Int_t j=0; j<=i; j++, k++ ){
0d14829a 2062 e[k] = 0;
2063 for( Int_t l=0; l<8; l++ ) e[k]+=mJC[i][l]*mJ[j][l];
f826d409 2064 }
2065
2066 return;
f826d409 2067 */
0d14829a 2068
2069 Double_t
2070 c6=fC[6], c7=fC[7], c8=fC[8], c17=fC[17], c18=fC[18],
2071 c24 = fC[24], c31 = fC[31];
2072
2073 Double_t
2074 cBC13 = cB*fC[13],
2075 mJC13 = c7 - cB*fC[9] + sB*fC[13],
2076 mJC14 = fC[11] - cBC13 + sB*fC[14],
2077 mJC23 = c8 + t*c18,
2078 mJC24 = fC[12] + t*fC[19],
2079 mJC33 = c*fC[9] + s*fC[13],
2080 mJC34 = c*fC[13] + s*fC[14],
2081 mJC43 = -s*fC[9] + c*fC[13],
2082 mJC44 = -s*fC[13] + c*fC[14];
2083
2084
2085 e[0]= fC[0] + 2*(sB*c6 + cB*fC[10]) + (sB*fC[9] + 2*cBC13)*sB + cB*cB*fC[14];
2086 e[1]= fC[1] - cB*c6 + sB*fC[10] + mJC13*sB + mJC14*cB;
2087 e[2]= fC[2] - cB*c7 + sB*fC[11] - mJC13*cB + mJC14*sB;
2088 e[3]= fC[3] + t*fC[15] + mJC23*sB + mJC24*cB;
2089 e[4]= fC[4] + t*fC[16] - mJC23*cB + mJC24*sB;
2090
2091 e[15]= fC[15] + c18*sB + fC[19]*cB;
2092 e[16]= fC[16] - c18*cB + fC[19]*sB;
2093 e[17]= c17 + fC[20]*t;
2094 e[18]= c18*c + fC[19]*s;
2095 e[19]= -c18*s + fC[19]*c;
2096
2097 e[5]= fC[5] + (c17 + e[17] )*t;
2098
2099 e[6]= c*c6 + s*fC[10] + mJC33*sB + mJC34*cB;
2100 e[7]= c*c7 + s*fC[11] - mJC33*cB + mJC34*sB;
2101 e[8]= c*c8 + s*fC[12] + e[18]*t;
2102 e[9]= mJC33*c + mJC34*s;
2103 e[10]= -s*c6 + c*fC[10] + mJC43*sB + mJC44*cB;
2104
2105
2106 e[11]= -s*c7 + c*fC[11] - mJC43*cB + mJC44*sB;
2107 e[12]= -s*c8 + c*fC[12] + e[19]*t;
2108 e[13]= mJC43*c + mJC44*s;
2109 e[14]= -mJC43*s + mJC44*c;
2110 e[20]= fC[20];
2111 e[21]= fC[21] + fC[25]*cB + c24*sB;
2112 e[22]= fC[22] - c24*cB + fC[25]*sB;
2113 e[23]= fC[23] + fC[26]*t;
2114 e[24]= c*c24 + s*fC[25];
2115 e[25]= c*fC[25] - c24*s;
2116 e[26]= fC[26];
2117 e[27]= fC[27];
2118 e[28]= fC[28] + fC[32]*cB + c31*sB;
2119 e[29]= fC[29] - c31*cB + fC[32]*sB;
2120 e[30]= fC[30] + fC[33]*t;
2121 e[31]= c*c31 + s*fC[32];
2122 e[32]= c*fC[32] - s*c31;
2123 e[33]= fC[33];
2124 e[34]= fC[34];
2125 e[35]= fC[35];
f826d409 2126}
2127
2128
2129Double_t AliKFParticleBase::GetDistanceFromVertex( const AliKFParticleBase &Vtx ) const
2130{
2131 //* Calculate distance from vertex [cm]
2132
2133 return GetDistanceFromVertex( Vtx.fP );
2134}
2135
2136Double_t AliKFParticleBase::GetDistanceFromVertex( const Double_t vtx[] ) const
2137{
2138 //* Calculate distance from vertex [cm]
2139
2140 Double_t mP[8], mC[36];
2141 Transport( GetDStoPoint(vtx), mP, mC );
2142 Double_t d[3]={ vtx[0]-mP[0], vtx[1]-mP[1], vtx[2]-mP[2]};
2143 return TMath::Sqrt( d[0]*d[0]+d[1]*d[1]+d[2]*d[2] );
2144}
2145
616ffc76 2146Double_t AliKFParticleBase::GetDistanceFromParticle( const AliKFParticleBase &p )
f826d409 2147 const
2148{
616ffc76 2149 //* Calculate distance to other particle [cm]
f826d409 2150
2151 Double_t dS, dS1;
616ffc76 2152 GetDStoParticle( p, dS, dS1 );
f826d409 2153 Double_t mP[8], mC[36], mP1[8], mC1[36];
616ffc76 2154 Transport( dS, mP, mC );
2155 p.Transport( dS1, mP1, mC1 );
f826d409 2156 Double_t dx = mP[0]-mP1[0];
2157 Double_t dy = mP[1]-mP1[1];
2158 Double_t dz = mP[2]-mP1[2];
55ac3e1e 2159 dz = 0;
f826d409 2160 return TMath::Sqrt(dx*dx+dy*dy+dz*dz);
2161}
2162
2163Double_t AliKFParticleBase::GetDeviationFromVertex( const AliKFParticleBase &Vtx ) const
2164{
2165 //* Calculate sqrt(Chi2/ndf) deviation from vertex
2166
2167 return GetDeviationFromVertex( Vtx.fP, Vtx.fC );
2168}
2169
2170
2171Double_t AliKFParticleBase::GetDeviationFromVertex( const Double_t v[], const Double_t Cv[] ) const
2172{
2173 //* Calculate sqrt(Chi2/ndf) deviation from vertex
2174 //* v = [xyz], Cv=[Cxx,Cxy,Cyy,Cxz,Cyz,Czz]-covariance matrix
2175
2176 Double_t mP[8];
2177 Double_t mC[36];
2178
2179 Transport( GetDStoPoint(v), mP, mC );
2180
2181 Double_t d[3]={ v[0]-mP[0], v[1]-mP[1], v[2]-mP[2]};
2182
2183 Double_t sigmaS = .1+10.*TMath::Sqrt( (d[0]*d[0]+d[1]*d[1]+d[2]*d[2])/
2184 (mP[3]*mP[3]+mP[4]*mP[4]+mP[5]*mP[5]) );
2185
2186
2187 Double_t h[3] = { mP[3]*sigmaS, mP[4]*sigmaS, mP[5]*sigmaS };
2188
2189 Double_t mSi[6] =
2190 { mC[0] +h[0]*h[0],
2191 mC[1] +h[1]*h[0], mC[2] +h[1]*h[1],
2192 mC[3] +h[2]*h[0], mC[4] +h[2]*h[1], mC[5] +h[2]*h[2] };
2193
2194 if( Cv ){
2195 mSi[0]+=Cv[0];
2196 mSi[1]+=Cv[1];
2197 mSi[2]+=Cv[2];
2198 mSi[3]+=Cv[3];
2199 mSi[4]+=Cv[4];
2200 mSi[5]+=Cv[5];
2201 }
2202
2203 Double_t mS[6];
2204
2205 mS[0] = mSi[2]*mSi[5] - mSi[4]*mSi[4];
2206 mS[1] = mSi[3]*mSi[4] - mSi[1]*mSi[5];
2207 mS[2] = mSi[0]*mSi[5] - mSi[3]*mSi[3];
2208 mS[3] = mSi[1]*mSi[4] - mSi[2]*mSi[3];
2209 mS[4] = mSi[1]*mSi[3] - mSi[0]*mSi[4];
2210 mS[5] = mSi[0]*mSi[2] - mSi[1]*mSi[1];
2211
2212 Double_t s = ( mSi[0]*mS[0] + mSi[1]*mS[1] + mSi[3]*mS[3] );
2213 s = ( s > 1.E-20 ) ?1./s :0;
2214
2215 return TMath::Sqrt( TMath::Abs(s*( ( mS[0]*d[0] + mS[1]*d[1] + mS[3]*d[2])*d[0]
2216 +(mS[1]*d[0] + mS[2]*d[1] + mS[4]*d[2])*d[1]
2217 +(mS[3]*d[0] + mS[4]*d[1] + mS[5]*d[2])*d[2] ))/2);
2218}
2219
2220
616ffc76 2221Double_t AliKFParticleBase::GetDeviationFromParticle( const AliKFParticleBase &p )
f826d409 2222 const
2223{
616ffc76 2224 //* Calculate sqrt(Chi2/ndf) deviation from other particle
f826d409 2225
2226 Double_t dS, dS1;
616ffc76 2227 GetDStoParticle( p, dS, dS1 );
f826d409 2228 Double_t mP1[8], mC1[36];
616ffc76 2229 p.Transport( dS1, mP1, mC1 );
f826d409 2230
2231 Double_t d[3]={ fP[0]-mP1[0], fP[1]-mP1[1], fP[2]-mP1[2]};
2232
2233 Double_t sigmaS = .1+10.*TMath::Sqrt( (d[0]*d[0]+d[1]*d[1]+d[2]*d[2])/
616ffc76 2234 (mP1[3]*mP1[3]+mP1[4]*mP1[4]+mP1[5]*mP1[5]) );
f826d409 2235
2236 Double_t h[3] = { mP1[3]*sigmaS, mP1[4]*sigmaS, mP1[5]*sigmaS };
2237
2238 mC1[0] +=h[0]*h[0];
2239 mC1[1] +=h[1]*h[0];
2240 mC1[2] +=h[1]*h[1];
2241 mC1[3] +=h[2]*h[0];
2242 mC1[4] +=h[2]*h[1];
2243 mC1[5] +=h[2]*h[2];
2244
2245 return GetDeviationFromVertex( mP1, mC1 )*TMath::Sqrt(2./1.);
2246}
2247
2248
2249
de0d0ceb 2250void AliKFParticleBase::SubtractFromVertex( AliKFParticleBase &Vtx ) const
24be0330 2251{
f826d409 2252 //* Subtract the particle from the vertex
de0d0ceb 2253
f826d409 2254 Double_t fld[3];
2255 {
de0d0ceb 2256 GetFieldValue( Vtx.fP, fld );
f826d409 2257 const Double_t kCLight = 0.000299792458;
2258 fld[0]*=kCLight; fld[1]*=kCLight; fld[2]*=kCLight;
2259 }
2260
2261 Double_t m[8];
2262 Double_t mCm[36];
f826d409 2263
de0d0ceb 2264 if( Vtx.fIsLinearized ){
2265 GetMeasurement( Vtx.fVtxGuess, m, mCm );
2266 } else {
2267 GetMeasurement( Vtx.fP, m, mCm );
f826d409 2268 }
de0d0ceb 2269
f826d409 2270 Double_t mV[6];
2271
de0d0ceb 2272 mV[ 0] = mCm[ 0];
2273 mV[ 1] = mCm[ 1];
2274 mV[ 2] = mCm[ 2];
2275 mV[ 3] = mCm[ 3];
2276 mV[ 4] = mCm[ 4];
2277 mV[ 5] = mCm[ 5];
f826d409 2278
2279 //*
2280
2281 Double_t mS[6];
2282 {
de0d0ceb 2283 Double_t mSi[6] = { mV[0]-Vtx.fC[0],
2284 mV[1]-Vtx.fC[1], mV[2]-Vtx.fC[2],
2285 mV[3]-Vtx.fC[3], mV[4]-Vtx.fC[4], mV[5]-Vtx.fC[5] };
f826d409 2286
2287 mS[0] = mSi[2]*mSi[5] - mSi[4]*mSi[4];
2288 mS[1] = mSi[3]*mSi[4] - mSi[1]*mSi[5];
2289 mS[2] = mSi[0]*mSi[5] - mSi[3]*mSi[3];
2290 mS[3] = mSi[1]*mSi[4] - mSi[2]*mSi[3];
2291 mS[4] = mSi[1]*mSi[3] - mSi[0]*mSi[4];
2292 mS[5] = mSi[0]*mSi[2] - mSi[1]*mSi[1];
2293
2294 Double_t s = ( mSi[0]*mS[0] + mSi[1]*mS[1] + mSi[3]*mS[3] );
2295 s = ( s > 1.E-20 ) ?1./s :0;
2296 mS[0]*=s;
2297 mS[1]*=s;
2298 mS[2]*=s;
2299 mS[3]*=s;
2300 mS[4]*=s;
2301 mS[5]*=s;
2302 }
2303
2304 //* Residual (measured - estimated)
2305
de0d0ceb 2306 Double_t zeta[3] = { m[0]-Vtx.fP[0], m[1]-Vtx.fP[1], m[2]-Vtx.fP[2] };
f826d409 2307
2308 //* mCHt = mCH' - D'
2309
2310 Double_t mCHt0[3], mCHt1[3], mCHt2[3];
2311
de0d0ceb 2312 mCHt0[0]=Vtx.fC[ 0] ; mCHt1[0]=Vtx.fC[ 1] ; mCHt2[0]=Vtx.fC[ 3] ;
2313 mCHt0[1]=Vtx.fC[ 1] ; mCHt1[1]=Vtx.fC[ 2] ; mCHt2[1]=Vtx.fC[ 4] ;
2314 mCHt0[2]=Vtx.fC[ 3] ; mCHt1[2]=Vtx.fC[ 4] ; mCHt2[2]=Vtx.fC[ 5] ;
f826d409 2315
2316 //* Kalman gain K = mCH'*S
2317
2318 Double_t k0[3], k1[3], k2[3];
2319
2320 for(Int_t i=0;i<3;++i){
2321 k0[i] = mCHt0[i]*mS[0] + mCHt1[i]*mS[1] + mCHt2[i]*mS[3];
2322 k1[i] = mCHt0[i]*mS[1] + mCHt1[i]*mS[2] + mCHt2[i]*mS[4];
2323 k2[i] = mCHt0[i]*mS[3] + mCHt1[i]*mS[4] + mCHt2[i]*mS[5];
2324 }
2325
2326 //* New estimation of the vertex position r += K*zeta
2327
de0d0ceb 2328 Double_t dChi2 = -(mS[0]*zeta[0] + mS[1]*zeta[1] + mS[3]*zeta[2])*zeta[0]
2329 + (mS[1]*zeta[0] + mS[2]*zeta[1] + mS[4]*zeta[2])*zeta[1]
2330 + (mS[3]*zeta[0] + mS[4]*zeta[1] + mS[5]*zeta[2])*zeta[2];
2331
2332 if( Vtx.fChi2 - dChi2 < 0 ) return;
2333
f826d409 2334 for(Int_t i=0;i<3;++i)
de0d0ceb 2335 Vtx.fP[i] -= k0[i]*zeta[0] + k1[i]*zeta[1] + k2[i]*zeta[2];
f826d409 2336
2337 //* New covariance matrix C -= K*(mCH')'
2338
2339 for(Int_t i=0, k=0;i<3;++i){
2340 for(Int_t j=0;j<=i;++j,++k)
de0d0ceb 2341 Vtx.fC[k] += k0[i]*mCHt0[j] + k1[i]*mCHt1[j] + k2[i]*mCHt2[j];
f826d409 2342 }
2343
2344 //* Calculate Chi^2
de0d0ceb 2345
2346 Vtx.fNDF -= 2;
2347 Vtx.fChi2 -= dChi2;
f826d409 2348}
2349
2350
2351
2352void AliKFParticleBase::TransportLine( Double_t dS,
2353 Double_t P[], Double_t C[] ) const
2354{
2355 //* Transport the particle as a straight line
2356
2357 P[0] = fP[0] + dS*fP[3];
2358 P[1] = fP[1] + dS*fP[4];
2359 P[2] = fP[2] + dS*fP[5];
2360 P[3] = fP[3];
2361 P[4] = fP[4];
2362 P[5] = fP[5];
2363 P[6] = fP[6];
2364 P[7] = fP[7];
2365
2366 Double_t c6 = fC[ 6] + dS*fC[ 9];
2367 Double_t c11 = fC[11] + dS*fC[14];
2368 Double_t c17 = fC[17] + dS*fC[20];
2369 Double_t sc13 = dS*fC[13];
2370 Double_t sc18 = dS*fC[18];
2371 Double_t sc19 = dS*fC[19];
2372
2373 C[ 0] = fC[ 0] + dS*( fC[ 6] + c6 );
2374 C[ 2] = fC[ 2] + dS*( fC[11] + c11 );
2375 C[ 5] = fC[ 5] + dS*( fC[17] + c17 );
2376
2377 C[ 7] = fC[ 7] + sc13;
2378 C[ 8] = fC[ 8] + sc18;
2379 C[ 9] = fC[ 9];
2380
2381 C[12] = fC[12] + sc19;
2382
2383 C[ 1] = fC[ 1] + dS*( fC[10] + C[ 7] );
2384 C[ 3] = fC[ 3] + dS*( fC[15] + C[ 8] );
2385 C[ 4] = fC[ 4] + dS*( fC[16] + C[12] );
2386 C[ 6] = c6;
2387
2388 C[10] = fC[10] + sc13;
2389 C[11] = c11;
2390
2391 C[13] = fC[13];
2392 C[14] = fC[14];
2393 C[15] = fC[15] + sc18;
2394 C[16] = fC[16] + sc19;
2395 C[17] = c17;
2396
2397 C[18] = fC[18];
2398 C[19] = fC[19];
2399 C[20] = fC[20];
2400 C[21] = fC[21] + dS*fC[24];
2401 C[22] = fC[22] + dS*fC[25];
2402 C[23] = fC[23] + dS*fC[26];
2403
2404 C[24] = fC[24];
2405 C[25] = fC[25];
2406 C[26] = fC[26];
2407 C[27] = fC[27];
2408 C[28] = fC[28] + dS*fC[31];
2409 C[29] = fC[29] + dS*fC[32];
2410 C[30] = fC[30] + dS*fC[33];
2411
2412 C[31] = fC[31];
2413 C[32] = fC[32];
2414 C[33] = fC[33];
2415 C[34] = fC[34];
2416 C[35] = fC[35];
2417}
2418
2419
a65041d0 2420void AliKFParticleBase::ConstructGammaBz( const AliKFParticleBase &daughter1,
2421 const AliKFParticleBase &daughter2, double Bz )
2422{
2423 //* Create gamma
2424
2425 const AliKFParticleBase *daughters[2] = { &daughter1, &daughter2};
2426
2427 double v0[3];
2428
2429 if( !fIsLinearized ){
2430 Double_t ds, ds1;
2431 Double_t m[8];
2432 Double_t mCd[36];
2433 daughter1.GetDStoParticle(daughter2, ds, ds1);
2434 daughter1.Transport( ds, m, mCd );
55ac3e1e 2435 fP[0] = m[0];
2436 fP[1] = m[1];
2437 fP[2] = m[2];
a65041d0 2438 daughter2.Transport( ds1, m, mCd );
55ac3e1e 2439 fP[0] = .5*( fP[0] + m[0] );
2440 fP[1] = .5*( fP[1] + m[1] );
2441 fP[2] = .5*( fP[2] + m[2] );
a65041d0 2442 } else {
55ac3e1e 2443 fP[0] = fVtxGuess[0];
2444 fP[1] = fVtxGuess[1];
2445 fP[2] = fVtxGuess[2];
a65041d0 2446 }
2447
a65041d0 2448 double daughterP[2][8], daughterC[2][36];
2449 double vtxMom[2][3];
2450
55ac3e1e 2451 int nIter = fIsLinearized ?1 :2;
a65041d0 2452
55ac3e1e 2453 for( int iter=0; iter<nIter; iter++){
a65041d0 2454
55ac3e1e 2455 v0[0] = fP[0];
2456 v0[1] = fP[1];
2457 v0[2] = fP[2];
a65041d0 2458
55ac3e1e 2459 fAtProductionVertex = 0;
2460 fSFromDecay = 0;
2461 fP[0] = v0[0];
2462 fP[1] = v0[1];
2463 fP[2] = v0[2];
2464 fP[3] = 0;
2465 fP[4] = 0;
2466 fP[5] = 0;
2467 fP[6] = 0;
2468 fP[7] = 0;
2469
2470
2471 // fit daughters to the vertex guess
a65041d0 2472
55ac3e1e 2473 {
2474 for( int id=0; id<2; id++ ){
2475
2476 double *p = daughterP[id];
2477 double *mC = daughterC[id];
2478
2479 daughters[id]->GetMeasurement( v0, p, mC );
2480
2481 Double_t mAi[6];
2482 InvertSym3(mC, mAi );
2483
2484 Double_t mB[3][3];
2485
2486 mB[0][0] = mC[ 6]*mAi[0] + mC[ 7]*mAi[1] + mC[ 8]*mAi[3];
2487 mB[0][1] = mC[ 6]*mAi[1] + mC[ 7]*mAi[2] + mC[ 8]*mAi[4];
2488 mB[0][2] = mC[ 6]*mAi[3] + mC[ 7]*mAi[4] + mC[ 8]*mAi[5];
2489
2490 mB[1][0] = mC[10]*mAi[0] + mC[11]*mAi[1] + mC[12]*mAi[3];
2491 mB[1][1] = mC[10]*mAi[1] + mC[11]*mAi[2] + mC[12]*mAi[4];
2492 mB[1][2] = mC[10]*mAi[3] + mC[11]*mAi[4] + mC[12]*mAi[5];
2493
2494 mB[2][0] = mC[15]*mAi[0] + mC[16]*mAi[1] + mC[17]*mAi[3];
2495 mB[2][1] = mC[15]*mAi[1] + mC[16]*mAi[2] + mC[17]*mAi[4];
2496 mB[2][2] = mC[15]*mAi[3] + mC[16]*mAi[4] + mC[17]*mAi[5];
2497
2498 Double_t z[3] = { v0[0]-p[0], v0[1]-p[1], v0[2]-p[2] };
2499
2500 vtxMom[id][0] = p[3] + mB[0][0]*z[0] + mB[0][1]*z[1] + mB[0][2]*z[2];
2501 vtxMom[id][1] = p[4] + mB[1][0]*z[0] + mB[1][1]*z[1] + mB[1][2]*z[2];
2502 vtxMom[id][2] = p[5] + mB[2][0]*z[0] + mB[2][1]*z[1] + mB[2][2]*z[2];
2503
2504 daughters[id]->Transport( daughters[id]->GetDStoPoint(v0), p, mC );
a65041d0 2505
55ac3e1e 2506 }
a65041d0 2507
55ac3e1e 2508 } // fit daughters to guess
2509
2510
2511 // fit new vertex
2512 {
a65041d0 2513
55ac3e1e 2514 double mpx0 = vtxMom[0][0]+vtxMom[1][0];
2515 double mpy0 = vtxMom[0][1]+vtxMom[1][1];
2516 double mpt0 = TMath::Sqrt(mpx0*mpx0 + mpy0*mpy0);
2517 // double a0 = TMath::ATan2(mpy0,mpx0);
a65041d0 2518
55ac3e1e 2519 double ca0 = mpx0/mpt0;
2520 double sa0 = mpy0/mpt0;
2521 double r[3] = { v0[0], v0[1], v0[2] };
2522 double mC[3][3] = {{10000., 0 , 0 },
2523 {0, 10000., 0 },
2524 {0, 0, 10000. } };
2525 double chi2=0;
a65041d0 2526
55ac3e1e 2527 for( int id=0; id<2; id++ ){
2528 const Double_t kCLight = 0.000299792458;
2529 Double_t q = Bz*daughters[id]->GetQ()*kCLight;
2530 Double_t px0 = vtxMom[id][0];
2531 Double_t py0 = vtxMom[id][1];
2532 Double_t pz0 = vtxMom[id][2];
2533 Double_t pt0 = TMath::Sqrt(px0*px0+py0*py0);
2534 Double_t mG[3][6], mB[3], mH[3][3];
2535 // r = {vx,vy,vz};
2536 // m = {x,y,z,Px,Py,Pz};
2537 // V = daughter.C
2538 // G*m + B = H*r;
2539 // q*x + Py - q*vx - sin(a)*Pt = 0
2540 // q*y - Px - q*vy + cos(a)*Pt = 0
2541 // (Px*cos(a) + Py*sin(a) ) (vz -z) - Pz( cos(a)*(vx-x) + sin(a)*(vy-y)) = 0
2542
2543 mG[0][0] = q;
2544 mG[0][1] = 0;
2545 mG[0][2] = 0;
2546 mG[0][3] = -sa0*px0/pt0;
2547 mG[0][4] = 1 -sa0*py0/pt0;
2548 mG[0][5] = 0;
2549 mH[0][0] = q;
2550 mH[0][1] = 0;
2551 mH[0][2] = 0;
2552 mB[0] = py0 - sa0*pt0 - mG[0][3]*px0 - mG[0][4]*py0 ;
2553
2554 // q*y - Px - q*vy + cos(a)*Pt = 0
2555
2556 mG[1][0] = 0;
2557 mG[1][1] = q;
2558 mG[1][2] = 0;
2559 mG[1][3] = -1 + ca0*px0/pt0;
2560 mG[1][4] = + ca0*py0/pt0;
2561 mG[1][5] = 0;
2562 mH[1][0] = 0;
2563 mH[1][1] = q;
2564 mH[1][2] = 0;
2565 mB[1] = -px0 + ca0*pt0 - mG[1][3]*px0 - mG[1][4]*py0 ;
2566
2567 // (Px*cos(a) + Py*sin(a) ) (z -vz) - Pz( cos(a)*(x-vx) + sin(a)*(y-vy)) = 0
a65041d0 2568
55ac3e1e 2569 mG[2][0] = -pz0*ca0;
2570 mG[2][1] = -pz0*sa0;
2571 mG[2][2] = px0*ca0 + py0*sa0;
2572 mG[2][3] = 0;
2573 mG[2][4] = 0;
2574 mG[2][5] = 0;
2575
2576 mH[2][0] = mG[2][0];
2577 mH[2][1] = mG[2][1];
2578 mH[2][2] = mG[2][2];
2579
2580 mB[2] = 0;
2581
2582 // fit the vertex
a65041d0 2583
55ac3e1e 2584 // V = GVGt
a65041d0 2585
55ac3e1e 2586 double mGV[3][6];
2587 double mV[6];
2588 double m[3];
2589 for( int i=0; i<3; i++ ){
2590 m[i] = mB[i];
2591 for( int k=0; k<6; k++ ) m[i]+=mG[i][k]*daughterP[id][k];
a65041d0 2592 }
55ac3e1e 2593 for( int i=0; i<3; i++ ){
2594 for( int j=0; j<6; j++ ){
2595 mGV[i][j] = 0;
2596 for( int k=0; k<6; k++ ) mGV[i][j]+=mG[i][k]*daughterC[id][ IJ(k,j) ];
2597 }
a65041d0 2598 }
55ac3e1e 2599 for( int i=0, k=0; i<3; i++ ){
2600 for( int j=0; j<=i; j++,k++ ){
2601 mV[k] = 0;
2602 for( int l=0; l<6; l++ ) mV[k]+=mGV[i][l]*mG[j][l];
2603 }
2604 }
2605
a65041d0 2606
55ac3e1e 2607 //* CHt
2608
2609 Double_t mCHt[3][3];
2610 Double_t mHCHt[6];
2611 Double_t mHr[3];
2612 for( int i=0; i<3; i++ ){
2613 mHr[i] = 0;
2614 for( int k=0; k<3; k++ ) mHr[i]+= mH[i][k]*r[k];
2615 }
a65041d0 2616
55ac3e1e 2617 for( int i=0; i<3; i++ ){
2618 for( int j=0; j<3; j++){
2619 mCHt[i][j] = 0;
2620 for( int k=0; k<3; k++ ) mCHt[i][j]+= mC[i][k]*mH[j][k];
2621 }
a65041d0 2622 }
a65041d0 2623
55ac3e1e 2624 for( int i=0, k=0; i<3; i++ ){
2625 for( int j=0; j<=i; j++, k++ ){
2626 mHCHt[k] = 0;
2627 for( int l=0; l<3; l++ ) mHCHt[k]+= mH[i][l]*mCHt[l][j];
2628 }
a65041d0 2629 }
a65041d0 2630
55ac3e1e 2631 Double_t mS[6] = { mHCHt[0]+mV[0],
2632 mHCHt[1]+mV[1], mHCHt[2]+mV[2],
2633 mHCHt[3]+mV[3], mHCHt[4]+mV[4], mHCHt[5]+mV[5] };
a65041d0 2634
2635
55ac3e1e 2636 InvertSym3(mS,mS);
a65041d0 2637
55ac3e1e 2638 //* Residual (measured - estimated)
a65041d0 2639
55ac3e1e 2640 Double_t zeta[3] = { m[0]-mHr[0], m[1]-mHr[1], m[2]-mHr[2] };
a65041d0 2641
55ac3e1e 2642 //* Kalman gain K = mCH'*S
a65041d0 2643
55ac3e1e 2644 Double_t k[3][3];
a65041d0 2645
55ac3e1e 2646 for(Int_t i=0;i<3;++i){
2647 k[i][0] = mCHt[i][0]*mS[0] + mCHt[i][1]*mS[1] + mCHt[i][2]*mS[3];
2648 k[i][1] = mCHt[i][0]*mS[1] + mCHt[i][1]*mS[2] + mCHt[i][2]*mS[4];
2649 k[i][2] = mCHt[i][0]*mS[3] + mCHt[i][1]*mS[4] + mCHt[i][2]*mS[5];
2650 }
a65041d0 2651
55ac3e1e 2652 //* New estimation of the vertex position r += K*zeta
a65041d0 2653
55ac3e1e 2654 for(Int_t i=0;i<3;++i)
2655 r[i] = r[i] + k[i][0]*zeta[0] + k[i][1]*zeta[1] + k[i][2]*zeta[2];
a65041d0 2656
55ac3e1e 2657 //* New covariance matrix C -= K*(mCH')'
a65041d0 2658
55ac3e1e 2659 for(Int_t i=0;i<3;++i){
2660 for(Int_t j=0;j<=i;++j){
2661 mC[i][j] = mC[i][j] - (k[i][0]*mCHt[j][0] + k[i][1]*mCHt[j][1] + k[i][2]*mCHt[j][2]);
2662 mC[j][i] = mC[i][j];
2663 }
a65041d0 2664 }
a65041d0 2665
2666
55ac3e1e 2667 //* Calculate Chi^2
a65041d0 2668
55ac3e1e 2669 chi2 += ( ( mS[0]*zeta[0] + mS[1]*zeta[1] + mS[3]*zeta[2] )*zeta[0]
2670 +(mS[1]*zeta[0] + mS[2]*zeta[1] + mS[4]*zeta[2] )*zeta[1]
2671 +(mS[3]*zeta[0] + mS[4]*zeta[1] + mS[5]*zeta[2] )*zeta[2] );
2672 }
a65041d0 2673
55ac3e1e 2674 // store vertex
a65041d0 2675
55ac3e1e 2676 fNDF = 2;
2677 fChi2 = chi2;
2678 for( int i=0; i<3; i++ ) fP[i] = r[i];
2679 for( int i=0,k=0; i<3; i++ ){
2680 for( int j=0; j<=i; j++,k++ ){
2681 fC[k] = mC[i][j];
2682 }
a65041d0 2683 }
2684 }
55ac3e1e 2685
2686 } // iterations
a65041d0 2687
2688 // now fit daughters to the vertex
2689
2690 fQ = 0;
2691 fSFromDecay = 0;
2692
2693 for(Int_t i=3;i<8;++i) fP[i]=0.;
55ac3e1e 2694 for(Int_t i=6;i<35;++i) fC[i]=0.;
2695 fC[35] = 100.;
a65041d0 2696
2697 for( int id=0; id<2; id++ ){
2698
2699 double *p = daughterP[id];
2700 double *mC = daughterC[id];
2701 daughters[id]->GetMeasurement( v0, p, mC );
2702
2703 const Double_t *m = fP, *mV = fC;
2704
2705 Double_t mAi[6];
2706 InvertSym3(mC, mAi );
2707
2708 Double_t mB[4][3];
2709
2710 mB[0][0] = mC[ 6]*mAi[0] + mC[ 7]*mAi[1] + mC[ 8]*mAi[3];
2711 mB[0][1] = mC[ 6]*mAi[1] + mC[ 7]*mAi[2] + mC[ 8]*mAi[4];
2712 mB[0][2] = mC[ 6]*mAi[3] + mC[ 7]*mAi[4] + mC[ 8]*mAi[5];
2713
2714 mB[1][0] = mC[10]*mAi[0] + mC[11]*mAi[1] + mC[12]*mAi[3];
2715 mB[1][1] = mC[10]*mAi[1] + mC[11]*mAi[2] + mC[12]*mAi[4];
2716 mB[1][2] = mC[10]*mAi[3] + mC[11]*mAi[4] + mC[12]*mAi[5];
2717
2718 mB[2][0] = mC[15]*mAi[0] + mC[16]*mAi[1] + mC[17]*mAi[3];
2719 mB[2][1] = mC[15]*mAi[1] + mC[16]*mAi[2] + mC[17]*mAi[4];
2720 mB[2][2] = mC[15]*mAi[3] + mC[16]*mAi[4] + mC[17]*mAi[5];
2721
2722 mB[3][0] = mC[21]*mAi[0] + mC[22]*mAi[1] + mC[23]*mAi[3];
2723 mB[3][1] = mC[21]*mAi[1] + mC[22]*mAi[2] + mC[23]*mAi[4];
2724 mB[3][2] = mC[21]*mAi[3] + mC[22]*mAi[4] + mC[23]*mAi[5];
2725
2726
2727 Double_t z[3] = { m[0]-p[0], m[1]-p[1], m[2]-p[2] };
2728
2729 {
2730 Double_t mAV[6] = { mC[0]-mV[0], mC[1]-mV[1], mC[2]-mV[2],
2731 mC[3]-mV[3], mC[4]-mV[4], mC[5]-mV[5] };
2732
2733 Double_t mAVi[6];
2734 if( !InvertSym3(mAV, mAVi) ){
2735 Double_t dChi2 = ( +(mAVi[0]*z[0] + mAVi[1]*z[1] + mAVi[3]*z[2])*z[0]
2736 +(mAVi[1]*z[0] + mAVi[2]*z[1] + mAVi[4]*z[2])*z[1]
2737 +(mAVi[3]*z[0] + mAVi[4]*z[1] + mAVi[5]*z[2])*z[2] );
2738 fChi2+= TMath::Abs( dChi2 );
2739 }
2740 fNDF += 2;
2741 }
2742
2743 //* Add the daughter momentum to the particle momentum
2744
2745 fP[3]+= p[3] + mB[0][0]*z[0] + mB[0][1]*z[1] + mB[0][2]*z[2];
2746 fP[4]+= p[4] + mB[1][0]*z[0] + mB[1][1]*z[1] + mB[1][2]*z[2];
2747 fP[5]+= p[5] + mB[2][0]*z[0] + mB[2][1]*z[1] + mB[2][2]*z[2];
2748 fP[6]+= p[6] + mB[3][0]*z[0] + mB[3][1]*z[1] + mB[3][2]*z[2];
2749
2750 Double_t d0, d1, d2;
2751
2752 d0= mB[0][0]*mV[0] + mB[0][1]*mV[1] + mB[0][2]*mV[3] - mC[ 6];
2753 d1= mB[0][0]*mV[1] + mB[0][1]*mV[2] + mB[0][2]*mV[4] - mC[ 7];
2754 d2= mB[0][0]*mV[3] + mB[0][1]*mV[4] + mB[0][2]*mV[5] - mC[ 8];
2755
2756 //fC[6]+= mC[ 6] + d0;
2757 //fC[7]+= mC[ 7] + d1;
2758 //fC[8]+= mC[ 8] + d2;
2759 fC[9]+= mC[ 9] + d0*mB[0][0] + d1*mB[0][1] + d2*mB[0][2];
2760
2761 d0= mB[1][0]*mV[0] + mB[1][1]*mV[1] + mB[1][2]*mV[3] - mC[10];
2762 d1= mB[1][0]*mV[1] + mB[1][1]*mV[2] + mB[1][2]*mV[4] - mC[11];
2763 d2= mB[1][0]*mV[3] + mB[1][1]*mV[4] + mB[1][2]*mV[5] - mC[12];
2764
2765 //fC[10]+= mC[10]+ d0;
2766 //fC[11]+= mC[11]+ d1;
2767 //fC[12]+= mC[12]+ d2;
2768 fC[13]+= mC[13]+ d0*mB[0][0] + d1*mB[0][1] + d2*mB[0][2];
2769 fC[14]+= mC[14]+ d0*mB[1][0] + d1*mB[1][1] + d2*mB[1][2];
2770
2771 d0= mB[2][0]*mV[0] + mB[2][1]*mV[1] + mB[2][2]*mV[3] - mC[15];
2772 d1= mB[2][0]*mV[1] + mB[2][1]*mV[2] + mB[2][2]*mV[4] - mC[16];
2773 d2= mB[2][0]*mV[3] + mB[2][1]*mV[4] + mB[2][2]*mV[5] - mC[17];
2774
2775 //fC[15]+= mC[15]+ d0;
2776 //fC[16]+= mC[16]+ d1;
2777 //fC[17]+= mC[17]+ d2;
2778 fC[18]+= mC[18]+ d0*mB[0][0] + d1*mB[0][1] + d2*mB[0][2];
2779 fC[19]+= mC[19]+ d0*mB[1][0] + d1*mB[1][1] + d2*mB[1][2];
2780 fC[20]+= mC[20]+ d0*mB[2][0] + d1*mB[2][1] + d2*mB[2][2];
2781
2782 d0= mB[3][0]*mV[0] + mB[3][1]*mV[1] + mB[3][2]*mV[3] - mC[21];
2783 d1= mB[3][0]*mV[1] + mB[3][1]*mV[2] + mB[3][2]*mV[4] - mC[22];
2784 d2= mB[3][0]*mV[3] + mB[3][1]*mV[4] + mB[3][2]*mV[5] - mC[23];
2785
2786 //fC[21]+= mC[21] + d0;
2787 //fC[22]+= mC[22] + d1;
2788 //fC[23]+= mC[23] + d2;
2789 fC[24]+= mC[24] + d0*mB[0][0] + d1*mB[0][1] + d2*mB[0][2];
2790 fC[25]+= mC[25] + d0*mB[1][0] + d1*mB[1][1] + d2*mB[1][2];
2791 fC[26]+= mC[26] + d0*mB[2][0] + d1*mB[2][1] + d2*mB[2][2];
2792 fC[27]+= mC[27] + d0*mB[3][0] + d1*mB[3][1] + d2*mB[3][2];
2793 }
2794
57ddc2cb 2795// SetMassConstraint(0,0);
2796 SetNonlinearMassConstraint(0);
a65041d0 2797}
2798
24be0330 2799void AliKFParticleBase::GetArmenterosPodolanski(AliKFParticleBase& positive, AliKFParticleBase& negative, Double_t QtAlfa[2] )
2800{
2801 Double_t alpha = 0., qt = 0.;
2802 Double_t spx = positive.GetPx() + negative.GetPx();
2803 Double_t spy = positive.GetPy() + negative.GetPy();
2804 Double_t spz = positive.GetPz() + negative.GetPz();
2805 Double_t sp = sqrt(spx*spx + spy*spy + spz*spz);
2806 if( sp == 0.0) return;
2807 Double_t pn, pp, pln, plp;
2808
2809 pn = TMath::Sqrt(negative.GetPx()*negative.GetPx() + negative.GetPy()*negative.GetPy() + negative.GetPz()*negative.GetPz());
2810 pp = TMath::Sqrt(positive.GetPx()*positive.GetPx() + positive.GetPy()*positive.GetPy() + positive.GetPz()*positive.GetPz());
2811 pln = (negative.GetPx()*spx+negative.GetPy()*spy+negative.GetPz()*spz)/sp;
2812 plp = (positive.GetPx()*spx+positive.GetPy()*spy+positive.GetPz()*spz)/sp;
2813
2814 if( pn == 0.0) return;
2815 Double_t ptm = (1.-((pln/pn)*(pln/pn)));
2816 qt= (ptm>=0.)? pn*sqrt(ptm) :0;
2817 alpha = (plp-pln)/(plp+pln);
2818
2819 QtAlfa[0] = qt;
2820 QtAlfa[1] = alpha;
2821}
2822
2823void AliKFParticleBase::RotateXY(Double_t angle, Double_t Vtx[3])
2824{
2825 // Rotates the KFParticle object around OZ axis, OZ axis is set by the vertex position
2826 // Double_t angle - angle of rotation in XY plane in [rad]
2827 // Double_t Vtx[3] - position of the vertex in [cm]
24be0330 2828
95142b87 2829 // Before rotation the center of the coordinat system should be moved to the vertex position; move back after rotation
2830 X() = X() - Vtx[0];
2831 Y() = Y() - Vtx[1];
2832 Z() = Z() - Vtx[2];
24be0330 2833
2834 // Rotate the kf particle
2835 Double_t c = TMath::Cos(angle);
2836 Double_t s = TMath::Sin(angle);
2837
2838 Double_t mA[8][ 8];
2839 for( Int_t i=0; i<8; i++ ){
2840 for( Int_t j=0; j<8; j++){
2841 mA[i][j] = 0;
2842 }
2843 }
2844 for( int i=0; i<8; i++ ){
2845 mA[i][i] = 1;
2846 }
2847 mA[0][0] = c; mA[0][1] = s;
2848 mA[1][0] = -s; mA[1][1] = c;
2849 mA[3][3] = c; mA[3][4] = s;
2850 mA[4][3] = -s; mA[4][4] = c;
2851
2852 Double_t mAC[8][8];
2853 Double_t mAp[8];
2854
2855 for( Int_t i=0; i<8; i++ ){
2856 mAp[i] = 0;
2857 for( Int_t k=0; k<8; k++){
2858 mAp[i]+=mA[i][k] * fP[k];
2859 }
2860 }
2861
2862 for( Int_t i=0; i<8; i++){
2863 fP[i] = mAp[i];
2864 }
2865
2866 for( Int_t i=0; i<8; i++ ){
2867 for( Int_t j=0; j<8; j++ ){
2868 mAC[i][j] = 0;
2869 for( Int_t k=0; k<8; k++ ){
2870 mAC[i][j]+= mA[i][k] * GetCovariance(k,j);
2871 }
2872 }
2873 }
2874
2875 for( Int_t i=0; i<8; i++ ){
2876 for( Int_t j=0; j<=i; j++ ){
2877 Double_t xx = 0;
2878 for( Int_t k=0; k<8; k++){
2879 xx+= mAC[i][k]*mA[j][k];
2880 }
2881 Covariance(i,j) = xx;
2882 }
2883 }
2884
95142b87 2885 X() = GetX() + Vtx[0];
2886 Y() = GetY() + Vtx[1];
2887 Z() = GetZ() + Vtx[2];
24be0330 2888}
2889
a65041d0 2890Bool_t AliKFParticleBase::InvertSym3( const Double_t A[], Double_t Ai[] )
2891{
2892 //* Invert symmetric matric stored in low-triagonal form
2893
2894 bool ret = 0;
2895 double a0 = A[0], a1 = A[1], a2 = A[2], a3 = A[3];
2896
2897 Ai[0] = a2*A[5] - A[4]*A[4];
2898 Ai[1] = a3*A[4] - a1*A[5];
2899 Ai[3] = a1*A[4] - a2*a3;
2900 Double_t det = (a0*Ai[0] + a1*Ai[1] + a3*Ai[3]);
57ddc2cb 2901 if( TMath::Abs(det)>1.e-20 ) det = 1./det;
a65041d0 2902 else{
2903 det = 0;
2904 ret = 1;
2905 }
2906 Ai[0] *= det;
2907 Ai[1] *= det;
2908 Ai[3] *= det;
2909 Ai[2] = ( a0*A[5] - a3*a3 )*det;
2910 Ai[4] = ( a1*a3 - a0*A[4] )*det;
2911 Ai[5] = ( a0*a2 - a1*a1 )*det;
2912 return ret;
2913}
2914
f826d409 2915void AliKFParticleBase::MultQSQt( const Double_t Q[], const Double_t S[], Double_t SOut[] )
2916{
2917 //* Matrix multiplication Q*S*Q^T, Q - square matrix, S - symmetric
2918
2919 const Int_t kN= 8;
2920 Double_t mA[kN*kN];
2921
2922 for( Int_t i=0, ij=0; i<kN; i++ ){
2923 for( Int_t j=0; j<kN; j++, ++ij ){
2924 mA[ij] = 0 ;
2925 for( Int_t k=0; k<kN; ++k ) mA[ij]+= S[( k<=i ) ? i*(i+1)/2+k :k*(k+1)/2+i] * Q[ j*kN+k];
2926 }
2927 }
2928
2929 for( Int_t i=0; i<kN; i++ ){
2930 for( Int_t j=0; j<=i; j++ ){
2931 Int_t ij = ( j<=i ) ? i*(i+1)/2+j :j*(j+1)/2+i;
2932 SOut[ij] = 0 ;
2933 for( Int_t k=0; k<kN; k++ ) SOut[ij] += Q[ i*kN+k ] * mA[ k*kN+j ];
2934 }
2935 }
2936}
2937
2938
2939// 72-charachters line to define the printer border
2940//3456789012345678901234567890123456789012345678901234567890123456789012
446ce366 2941