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f826d409 | 1 | //--------------------------------------------------------------------------------- |
2 | // Implementation of the AliKFParticleBase class | |
3 | // . | |
4 | // @author S.Gorbunov, I.Kisel | |
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 © ALICE HLT Group =- | |
16 | //_________________________________________________________________________________ | |
17 | ||
18 | ||
19 | #include "AliKFParticleBase.h" | |
20 | #include "TMath.h" | |
21 | ||
effa6338 | 22 | ClassImp(AliKFParticleBase) |
f826d409 | 23 | |
24 | ||
25 | AliKFParticleBase::AliKFParticleBase() :fQ(0), fNDF(-3), fChi2(0), fSFromDecay(0), fAtProductionVertex(0), fIsLinearized(0) | |
26 | { | |
27 | //* Constructor | |
28 | ||
29 | Initialize(); | |
30 | } | |
e7b09c95 | 31 | |
32 | void AliKFParticleBase::Initialize( const Double_t Param[], const Double_t Cov[], Int_t Charge, Double_t Mass ) | |
33 | { | |
34 | // Constructor from "cartesian" track, particle mass hypothesis should be provided | |
35 | // | |
36 | // Param[6] = { X, Y, Z, Px, Py, Pz } - position and momentum | |
37 | // Cov [21] = lower-triangular part of the covariance matrix: | |
38 | // | |
39 | // ( 0 . . . . . ) | |
40 | // ( 1 2 . . . . ) | |
41 | // Cov. matrix = ( 3 4 5 . . . ) - numbering of covariance elements in Cov[] | |
42 | // ( 6 7 8 9 . . ) | |
43 | // ( 10 11 12 13 14 . ) | |
44 | // ( 15 16 17 18 19 20 ) | |
45 | ||
46 | ||
47 | for( Int_t i=0; i<6 ; i++ ) fP[i] = Param[i]; | |
48 | for( Int_t i=0; i<21; i++ ) fC[i] = Cov[i]; | |
49 | ||
50 | Double_t energy = TMath::Sqrt( Mass*Mass + fP[3]*fP[3] + fP[4]*fP[4] + fP[5]*fP[5]); | |
51 | fP[6] = energy; | |
52 | fP[7] = 0; | |
53 | fQ = Charge; | |
54 | fNDF = 0; | |
55 | fChi2 = 0; | |
56 | fAtProductionVertex = 0; | |
57 | fIsLinearized = 0; | |
58 | fSFromDecay = 0; | |
59 | ||
60 | Double_t energyInv = 1./energy; | |
61 | Double_t | |
62 | h0 = fP[3]*energyInv, | |
63 | h1 = fP[4]*energyInv, | |
64 | h2 = fP[5]*energyInv; | |
65 | ||
66 | fC[21] = h0*fC[ 6] + h1*fC[10] + h2*fC[15]; | |
67 | fC[22] = h0*fC[ 7] + h1*fC[11] + h2*fC[16]; | |
68 | fC[23] = h0*fC[ 8] + h1*fC[12] + h2*fC[17]; | |
69 | fC[24] = h0*fC[ 9] + h1*fC[13] + h2*fC[18]; | |
70 | fC[25] = h0*fC[13] + h1*fC[14] + h2*fC[19]; | |
71 | fC[26] = h0*fC[18] + h1*fC[19] + h2*fC[20]; | |
706952f5 | 72 | fC[27] = ( h0*h0*fC[ 9] + h1*h1*fC[14] + h2*h2*fC[20] |
73 | + 2*(h0*h1*fC[13] + h0*h2*fC[18] + h1*h2*fC[19] ) ); | |
e7b09c95 | 74 | for( Int_t i=28; i<36; i++ ) fC[i] = 0; |
75 | fC[35] = 1.; | |
76 | } | |
77 | ||
f826d409 | 78 | void AliKFParticleBase::Initialize() |
79 | { | |
80 | //* Initialise covariance matrix and set current parameters to 0.0 | |
81 | ||
82 | for( Int_t i=0; i<8; i++) fP[i] = 0; | |
83 | for(Int_t i=0;i<36;++i) fC[i]=0.; | |
84 | fC[0] = fC[2] = fC[5] = 100.; | |
85 | fC[35] = 1.; | |
86 | fNDF = -3; | |
87 | fChi2 = 0.; | |
88 | fQ = 0; | |
89 | fSFromDecay = 0; | |
90 | fAtProductionVertex = 0; | |
91 | fVtxGuess[0]=fVtxGuess[1]=fVtxGuess[2]=0.; | |
92 | fIsLinearized = 0; | |
93 | } | |
94 | ||
95 | void AliKFParticleBase::SetVtxGuess( Double_t x, Double_t y, Double_t z ) | |
96 | { | |
97 | //* Set decay vertex parameters for linearisation | |
98 | ||
99 | fVtxGuess[0] = x; | |
100 | fVtxGuess[1] = y; | |
101 | fVtxGuess[2] = z; | |
102 | fIsLinearized = 1; | |
103 | } | |
104 | ||
105 | ||
5fc72f28 | 106 | Int_t AliKFParticleBase::GetMomentum( Double_t &p, Double_t &error ) const |
f826d409 | 107 | { |
108 | //* Calculate particle momentum | |
109 | ||
110 | Double_t x = fP[3]; | |
111 | Double_t y = fP[4]; | |
112 | Double_t z = fP[5]; | |
113 | Double_t x2 = x*x; | |
114 | Double_t y2 = y*y; | |
115 | Double_t z2 = z*z; | |
116 | Double_t p2 = x2+y2+z2; | |
5fc72f28 | 117 | p = TMath::Sqrt(p2); |
118 | error = (x2*fC[9]+y2*fC[14]+z2*fC[20] + 2*(x*y*fC[13]+x*z*fC[18]+y*z*fC[19]) ); | |
119 | if( error>0 && p>1.e-4 ){ | |
120 | error = TMath::Sqrt(error)/p; | |
f826d409 | 121 | return 0; |
122 | } | |
123 | return 1; | |
124 | } | |
125 | ||
5fc72f28 | 126 | Int_t AliKFParticleBase::GetPt( Double_t &pt, Double_t &error ) const |
706952f5 | 127 | { |
128 | //* Calculate particle transverse momentum | |
129 | ||
130 | Double_t px = fP[3]; | |
131 | Double_t py = fP[4]; | |
132 | Double_t px2 = px*px; | |
133 | Double_t py2 = py*py; | |
134 | Double_t pt2 = px2+py2; | |
5fc72f28 | 135 | pt = TMath::Sqrt(pt2); |
136 | error = (px2*fC[9] + py2*fC[14] + 2*px*py*fC[13] ); | |
137 | if( error>0 && pt>1.e-4 ){ | |
138 | error = TMath::Sqrt(error)/pt; | |
706952f5 | 139 | return 0; |
140 | } | |
5fc72f28 | 141 | error = 1.e10; |
706952f5 | 142 | return 1; |
143 | } | |
144 | ||
5fc72f28 | 145 | Int_t AliKFParticleBase::GetEta( Double_t &eta, Double_t &error ) const |
706952f5 | 146 | { |
147 | //* Calculate particle pseudorapidity | |
148 | ||
149 | Double_t px = fP[3]; | |
150 | Double_t py = fP[4]; | |
151 | Double_t pz = fP[5]; | |
152 | Double_t pt2 = px*px + py*py; | |
153 | Double_t p2 = pt2 + pz*pz; | |
154 | Double_t p = TMath::Sqrt(p2); | |
155 | Double_t a = p + pz; | |
156 | Double_t b = p - pz; | |
5fc72f28 | 157 | eta = 1.e10; |
706952f5 | 158 | if( b > 1.e-8 ){ |
159 | Double_t c = a/b; | |
a65041d0 | 160 | if( c>1.e-8 ) eta = 0.5*TMath::Log(c); |
706952f5 | 161 | } |
162 | Double_t h3 = -px*pz; | |
a65041d0 | 163 | Double_t h4 = -py*pz; |
164 | Double_t pt4 = pt2*pt2; | |
165 | Double_t p2pt4 = p2*pt4; | |
166 | 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 | 167 | |
a65041d0 | 168 | if( error>0 && p2pt4>1.e-10 ){ |
169 | error = TMath::Sqrt(error/p2pt4); | |
706952f5 | 170 | return 0; |
171 | } | |
a65041d0 | 172 | |
5fc72f28 | 173 | error = 1.e10; |
706952f5 | 174 | return 1; |
175 | } | |
176 | ||
5fc72f28 | 177 | Int_t AliKFParticleBase::GetPhi( Double_t &phi, Double_t &error ) const |
706952f5 | 178 | { |
179 | //* Calculate particle polar angle | |
180 | ||
181 | Double_t px = fP[3]; | |
182 | Double_t py = fP[4]; | |
183 | Double_t px2 = px*px; | |
184 | Double_t py2 = py*py; | |
185 | Double_t pt2 = px2 + py2; | |
5fc72f28 | 186 | phi = TMath::ATan2(py,px); |
187 | error = (py2*fC[9] + px2*fC[14] - 2*px*py*fC[13] ); | |
188 | if( error>0 && pt2>1.e-4 ){ | |
189 | error = TMath::Sqrt(error)/pt2; | |
706952f5 | 190 | return 0; |
191 | } | |
5fc72f28 | 192 | error = 1.e10; |
706952f5 | 193 | return 1; |
194 | } | |
195 | ||
5fc72f28 | 196 | Int_t AliKFParticleBase::GetR( Double_t &r, Double_t &error ) const |
706952f5 | 197 | { |
198 | //* Calculate distance to the origin | |
199 | ||
200 | Double_t x = fP[0]; | |
201 | Double_t y = fP[1]; | |
202 | Double_t x2 = x*x; | |
203 | Double_t y2 = y*y; | |
5fc72f28 | 204 | r = TMath::Sqrt(x2 + y2); |
205 | error = (x2*fC[0] + y2*fC[2] - 2*x*y*fC[1] ); | |
206 | if( error>0 && r>1.e-4 ){ | |
207 | error = TMath::Sqrt(error)/r; | |
706952f5 | 208 | return 0; |
209 | } | |
5fc72f28 | 210 | error = 1.e10; |
706952f5 | 211 | return 1; |
212 | } | |
213 | ||
5fc72f28 | 214 | Int_t AliKFParticleBase::GetMass( Double_t &m, Double_t &error ) const |
f826d409 | 215 | { |
216 | //* Calculate particle mass | |
217 | ||
218 | // s = sigma^2 of m2/2 | |
219 | ||
220 | Double_t s = ( fP[3]*fP[3]*fC[9] + fP[4]*fP[4]*fC[14] + fP[5]*fP[5]*fC[20] | |
221 | + fP[6]*fP[6]*fC[27] | |
222 | +2*( + fP[3]*fP[4]*fC[13] + fP[5]*(fP[3]*fC[18] + fP[4]*fC[19]) | |
223 | - fP[6]*( fP[3]*fC[24] + fP[4]*fC[25] + fP[5]*fC[26] ) ) | |
224 | ); | |
706952f5 | 225 | Double_t m2 = TMath::Abs(fP[6]*fP[6] - fP[3]*fP[3] - fP[4]*fP[4] - fP[5]*fP[5]); |
5fc72f28 | 226 | m = TMath::Sqrt(m2); |
227 | if( m>1.e-10 ){ | |
616ffc76 | 228 | if( s>=0 ){ |
5fc72f28 | 229 | error = TMath::Sqrt(s)/m; |
616ffc76 | 230 | return 0; |
231 | } | |
f826d409 | 232 | } |
5fc72f28 | 233 | error = 1.e20; |
f826d409 | 234 | return 1; |
235 | } | |
236 | ||
237 | ||
5fc72f28 | 238 | Int_t AliKFParticleBase::GetDecayLength( Double_t &l, Double_t &error ) const |
f826d409 | 239 | { |
240 | //* Calculate particle decay length [cm] | |
241 | ||
242 | Double_t x = fP[3]; | |
243 | Double_t y = fP[4]; | |
244 | Double_t z = fP[5]; | |
245 | Double_t t = fP[7]; | |
246 | Double_t x2 = x*x; | |
247 | Double_t y2 = y*y; | |
248 | Double_t z2 = z*z; | |
249 | Double_t p2 = x2+y2+z2; | |
5fc72f28 | 250 | l = t*TMath::Sqrt(p2); |
f826d409 | 251 | if( p2>1.e-4){ |
5fc72f28 | 252 | error = p2*fC[35] + t*t/p2*(x2*fC[9]+y2*fC[14]+z2*fC[20] |
f826d409 | 253 | + 2*(x*y*fC[13]+x*z*fC[18]+y*z*fC[19]) ) |
254 | + 2*t*(x*fC[31]+y*fC[32]+z*fC[33]); | |
5fc72f28 | 255 | error = TMath::Sqrt(TMath::Abs(error)); |
f826d409 | 256 | return 0; |
257 | } | |
5fc72f28 | 258 | error = 1.e20; |
f826d409 | 259 | return 1; |
260 | } | |
261 | ||
446ce366 | 262 | Int_t AliKFParticleBase::GetDecayLengthXY( Double_t &l, Double_t &error ) const |
263 | { | |
264 | //* Calculate particle decay length in XY projection [cm] | |
265 | ||
266 | Double_t x = fP[3]; | |
267 | Double_t y = fP[4]; | |
268 | Double_t t = fP[7]; | |
269 | Double_t x2 = x*x; | |
270 | Double_t y2 = y*y; | |
271 | Double_t pt2 = x2+y2; | |
272 | l = t*TMath::Sqrt(pt2); | |
273 | if( pt2>1.e-4){ | |
274 | error = pt2*fC[35] + t*t/pt2*(x2*fC[9]+y2*fC[14] + 2*x*y*fC[13] ) | |
275 | + 2*t*(x*fC[31]+y*fC[32]); | |
276 | error = TMath::Sqrt(TMath::Abs(error)); | |
277 | return 0; | |
278 | } | |
279 | error = 1.e20; | |
280 | return 1; | |
281 | } | |
282 | ||
283 | ||
5fc72f28 | 284 | Int_t AliKFParticleBase::GetLifeTime( Double_t &tauC, Double_t &error ) const |
f826d409 | 285 | { |
286 | //* Calculate particle decay time [s] | |
287 | ||
288 | Double_t m, dm; | |
289 | GetMass( m, dm ); | |
290 | Double_t cTM = (-fP[3]*fC[31] - fP[4]*fC[32] - fP[5]*fC[33] + fP[6]*fC[34]); | |
5fc72f28 | 291 | tauC = fP[7]*m; |
292 | error = m*m*fC[35] + 2*fP[7]*cTM + fP[7]*fP[7]*dm*dm; | |
293 | if( error > 0 ){ | |
294 | error = TMath::Sqrt( error ); | |
f826d409 | 295 | return 0; |
296 | } | |
5fc72f28 | 297 | error = 1.e20; |
f826d409 | 298 | return 1; |
299 | } | |
300 | ||
301 | ||
302 | void AliKFParticleBase::operator +=( const AliKFParticleBase &Daughter ) | |
303 | { | |
304 | //* Add daughter via operator+= | |
305 | ||
306 | AddDaughter( Daughter ); | |
307 | } | |
308 | ||
706952f5 | 309 | Double_t AliKFParticleBase::GetSCorrection( const Double_t Part[], const Double_t XYZ[] ) |
310 | { | |
311 | //* Get big enough correction for S error to let the particle Part be fitted to XYZ point | |
312 | ||
313 | Double_t d[3] = { XYZ[0]-Part[0], XYZ[1]-Part[1], XYZ[2]-Part[2] }; | |
314 | Double_t p2 = Part[3]*Part[3]+Part[4]*Part[4]+Part[5]*Part[5]; | |
a65041d0 | 315 | 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 | 316 | return sigmaS; |
317 | } | |
616ffc76 | 318 | |
319 | void AliKFParticleBase::GetMeasurement( const Double_t XYZ[], Double_t m[], Double_t V[] ) const | |
320 | { | |
e7b09c95 | 321 | //* Get additional covariances V used during measurement |
322 | ||
616ffc76 | 323 | Double_t b[3]; |
324 | GetFieldValue( XYZ, b ); | |
325 | const Double_t kCLight = 0.000299792458; | |
326 | b[0]*=kCLight; b[1]*=kCLight; b[2]*=kCLight; | |
327 | ||
328 | Transport( GetDStoPoint(XYZ), m, V ); | |
329 | ||
706952f5 | 330 | Double_t sigmaS = GetSCorrection( m, XYZ ); |
616ffc76 | 331 | |
332 | Double_t h[6]; | |
333 | ||
334 | h[0] = m[3]*sigmaS; | |
335 | h[1] = m[4]*sigmaS; | |
336 | h[2] = m[5]*sigmaS; | |
337 | h[3] = ( h[1]*b[2]-h[2]*b[1] )*GetQ(); | |
338 | h[4] = ( h[2]*b[0]-h[0]*b[2] )*GetQ(); | |
339 | h[5] = ( h[0]*b[1]-h[1]*b[0] )*GetQ(); | |
340 | ||
616ffc76 | 341 | V[ 0]+= h[0]*h[0]; |
342 | V[ 1]+= h[1]*h[0]; | |
343 | V[ 2]+= h[1]*h[1]; | |
344 | V[ 3]+= h[2]*h[0]; | |
345 | V[ 4]+= h[2]*h[1]; | |
346 | V[ 5]+= h[2]*h[2]; | |
347 | ||
348 | V[ 6]+= h[3]*h[0]; | |
349 | V[ 7]+= h[3]*h[1]; | |
350 | V[ 8]+= h[3]*h[2]; | |
351 | V[ 9]+= h[3]*h[3]; | |
352 | ||
353 | V[10]+= h[4]*h[0]; | |
354 | V[11]+= h[4]*h[1]; | |
355 | V[12]+= h[4]*h[2]; | |
356 | V[13]+= h[4]*h[3]; | |
357 | V[14]+= h[4]*h[4]; | |
358 | ||
359 | V[15]+= h[5]*h[0]; | |
360 | V[16]+= h[5]*h[1]; | |
361 | V[17]+= h[5]*h[2]; | |
362 | V[18]+= h[5]*h[3]; | |
363 | V[19]+= h[5]*h[4]; | |
364 | V[20]+= h[5]*h[5]; | |
365 | } | |
366 | ||
616ffc76 | 367 | |
f826d409 | 368 | void AliKFParticleBase::AddDaughter( const AliKFParticleBase &Daughter ) |
369 | { | |
370 | //* Add daughter | |
371 | ||
616ffc76 | 372 | if( fNDF<-1 ){ // first daughter -> just copy |
373 | fNDF = -1; | |
374 | fQ = Daughter.GetQ(); | |
375 | for( Int_t i=0; i<7; i++) fP[i] = Daughter.fP[i]; | |
376 | for( Int_t i=0; i<28; i++) fC[i] = Daughter.fC[i]; | |
377 | fSFromDecay = 0; | |
378 | return; | |
379 | } | |
380 | ||
f826d409 | 381 | TransportToDecayVertex(); |
382 | ||
383 | Double_t b[3]; | |
384 | Int_t maxIter = 1; | |
385 | ||
386 | if( !fIsLinearized ){ | |
387 | if( fNDF==-1 ){ | |
388 | Double_t ds, ds1; | |
616ffc76 | 389 | GetDStoParticle(Daughter, ds, ds1); |
f826d409 | 390 | TransportToDS( ds ); |
616ffc76 | 391 | Double_t m[8]; |
392 | Double_t mCd[36]; | |
393 | Daughter.Transport( ds1, m, mCd ); | |
394 | fVtxGuess[0] = .5*( fP[0] + m[0] ); | |
395 | fVtxGuess[1] = .5*( fP[1] + m[1] ); | |
396 | fVtxGuess[2] = .5*( fP[2] + m[2] ); | |
397 | } else { | |
398 | fVtxGuess[0] = fP[0]; | |
399 | fVtxGuess[1] = fP[1]; | |
400 | fVtxGuess[2] = fP[2]; | |
f826d409 | 401 | } |
f826d409 | 402 | maxIter = 3; |
403 | } | |
404 | ||
405 | for( Int_t iter=0; iter<maxIter; iter++ ){ | |
406 | ||
407 | { | |
408 | GetFieldValue( fVtxGuess, b ); | |
409 | const Double_t kCLight = 0.000299792458; | |
410 | b[0]*=kCLight; b[1]*=kCLight; b[2]*=kCLight; | |
411 | } | |
f826d409 | 412 | |
616ffc76 | 413 | Double_t *ffP = fP, *ffC = fC, tmpP[8], tmpC[36]; |
de0d0ceb | 414 | if( fNDF==-1 ){ |
616ffc76 | 415 | GetMeasurement( fVtxGuess, tmpP, tmpC ); |
416 | ffP = tmpP; | |
417 | ffC = tmpC; | |
f826d409 | 418 | } |
419 | ||
e7b09c95 | 420 | Double_t m[8], mV[36]; |
de0d0ceb | 421 | |
e7b09c95 | 422 | if( Daughter.fC[35]>0 ){ |
423 | Daughter.GetMeasurement( fVtxGuess, m, mV ); | |
424 | } else { | |
425 | for( Int_t i=0; i<8; i++ ) m[i] = Daughter.fP[i]; | |
426 | for( Int_t i=0; i<36; i++ ) mV[i] = Daughter.fC[i]; | |
427 | } | |
de0d0ceb | 428 | |
f826d409 | 429 | //* |
430 | ||
431 | Double_t mS[6]; | |
432 | { | |
616ffc76 | 433 | Double_t mSi[6] = { ffC[0]+mV[0], |
434 | ffC[1]+mV[1], ffC[2]+mV[2], | |
435 | ffC[3]+mV[3], ffC[4]+mV[4], ffC[5]+mV[5] }; | |
de0d0ceb | 436 | |
f826d409 | 437 | mS[0] = mSi[2]*mSi[5] - mSi[4]*mSi[4]; |
438 | mS[1] = mSi[3]*mSi[4] - mSi[1]*mSi[5]; | |
439 | mS[2] = mSi[0]*mSi[5] - mSi[3]*mSi[3]; | |
440 | mS[3] = mSi[1]*mSi[4] - mSi[2]*mSi[3]; | |
441 | mS[4] = mSi[1]*mSi[3] - mSi[0]*mSi[4]; | |
442 | mS[5] = mSi[0]*mSi[2] - mSi[1]*mSi[1]; | |
443 | ||
706952f5 | 444 | Double_t s = ( mSi[0]*mS[0] + mSi[1]*mS[1] + mSi[3]*mS[3] ); |
445 | ||
f826d409 | 446 | s = ( s > 1.E-20 ) ?1./s :0; |
447 | mS[0]*=s; | |
448 | mS[1]*=s; | |
449 | mS[2]*=s; | |
450 | mS[3]*=s; | |
451 | mS[4]*=s; | |
452 | mS[5]*=s; | |
453 | } | |
454 | ||
455 | //* Residual (measured - estimated) | |
456 | ||
616ffc76 | 457 | Double_t zeta[3] = { m[0]-ffP[0], m[1]-ffP[1], m[2]-ffP[2] }; |
de0d0ceb | 458 | |
f826d409 | 459 | |
460 | //* CHt = CH' - D' | |
461 | ||
462 | Double_t mCHt0[7], mCHt1[7], mCHt2[7]; | |
463 | ||
616ffc76 | 464 | mCHt0[0]=ffC[ 0] ; mCHt1[0]=ffC[ 1] ; mCHt2[0]=ffC[ 3] ; |
465 | mCHt0[1]=ffC[ 1] ; mCHt1[1]=ffC[ 2] ; mCHt2[1]=ffC[ 4] ; | |
466 | mCHt0[2]=ffC[ 3] ; mCHt1[2]=ffC[ 4] ; mCHt2[2]=ffC[ 5] ; | |
467 | mCHt0[3]=ffC[ 6]-mV[ 6]; mCHt1[3]=ffC[ 7]-mV[ 7]; mCHt2[3]=ffC[ 8]-mV[ 8]; | |
468 | mCHt0[4]=ffC[10]-mV[10]; mCHt1[4]=ffC[11]-mV[11]; mCHt2[4]=ffC[12]-mV[12]; | |
469 | mCHt0[5]=ffC[15]-mV[15]; mCHt1[5]=ffC[16]-mV[16]; mCHt2[5]=ffC[17]-mV[17]; | |
470 | mCHt0[6]=ffC[21]-mV[21]; mCHt1[6]=ffC[22]-mV[22]; mCHt2[6]=ffC[23]-mV[23]; | |
f826d409 | 471 | |
472 | //* Kalman gain K = mCH'*S | |
473 | ||
474 | Double_t k0[7], k1[7], k2[7]; | |
475 | ||
476 | for(Int_t i=0;i<7;++i){ | |
477 | k0[i] = mCHt0[i]*mS[0] + mCHt1[i]*mS[1] + mCHt2[i]*mS[3]; | |
478 | k1[i] = mCHt0[i]*mS[1] + mCHt1[i]*mS[2] + mCHt2[i]*mS[4]; | |
479 | k2[i] = mCHt0[i]*mS[3] + mCHt1[i]*mS[4] + mCHt2[i]*mS[5]; | |
480 | } | |
481 | ||
4bbc290d | 482 | //* New estimation of the vertex position |
f826d409 | 483 | |
484 | if( iter<maxIter-1 ){ | |
485 | for(Int_t i=0; i<3; ++i) | |
616ffc76 | 486 | fVtxGuess[i]= ffP[i] + k0[i]*zeta[0]+k1[i]*zeta[1]+k2[i]*zeta[2]; |
f826d409 | 487 | continue; |
488 | } | |
489 | ||
490 | // last itearation -> update the particle | |
491 | ||
492 | //* Add the daughter momentum to the particle momentum | |
493 | ||
616ffc76 | 494 | ffP[ 3] += m[ 3]; |
495 | ffP[ 4] += m[ 4]; | |
496 | ffP[ 5] += m[ 5]; | |
497 | ffP[ 6] += m[ 6]; | |
f826d409 | 498 | |
616ffc76 | 499 | ffC[ 9] += mV[ 9]; |
500 | ffC[13] += mV[13]; | |
501 | ffC[14] += mV[14]; | |
502 | ffC[18] += mV[18]; | |
503 | ffC[19] += mV[19]; | |
504 | ffC[20] += mV[20]; | |
505 | ffC[24] += mV[24]; | |
506 | ffC[25] += mV[25]; | |
507 | ffC[26] += mV[26]; | |
508 | ffC[27] += mV[27]; | |
f826d409 | 509 | |
de0d0ceb | 510 | |
511 | //* New estimation of the vertex position r += K*zeta | |
f826d409 | 512 | |
513 | for(Int_t i=0;i<7;++i) | |
616ffc76 | 514 | fP[i] = ffP[i] + k0[i]*zeta[0] + k1[i]*zeta[1] + k2[i]*zeta[2]; |
f826d409 | 515 | |
516 | //* New covariance matrix C -= K*(mCH')' | |
de0d0ceb | 517 | |
f826d409 | 518 | for(Int_t i=0, k=0;i<7;++i){ |
de0d0ceb | 519 | for(Int_t j=0;j<=i;++j,++k){ |
616ffc76 | 520 | fC[k] = ffC[k] - (k0[i]*mCHt0[j] + k1[i]*mCHt1[j] + k2[i]*mCHt2[j] ); |
de0d0ceb | 521 | } |
f826d409 | 522 | } |
de0d0ceb | 523 | |
f826d409 | 524 | //* Calculate Chi^2 |
525 | ||
526 | fNDF += 2; | |
527 | fQ += Daughter.GetQ(); | |
528 | fSFromDecay = 0; | |
529 | fChi2 += (mS[0]*zeta[0] + mS[1]*zeta[1] + mS[3]*zeta[2])*zeta[0] | |
530 | + (mS[1]*zeta[0] + mS[2]*zeta[1] + mS[4]*zeta[2])*zeta[1] | |
706952f5 | 531 | + (mS[3]*zeta[0] + mS[4]*zeta[1] + mS[5]*zeta[2])*zeta[2]; |
de0d0ceb | 532 | |
f826d409 | 533 | } |
534 | } | |
535 | ||
706952f5 | 536 | |
f826d409 | 537 | void AliKFParticleBase::SetProductionVertex( const AliKFParticleBase &Vtx ) |
538 | { | |
706952f5 | 539 | //* Set production vertex for the particle, when the particle was not used in the vertex fit |
f826d409 | 540 | |
541 | const Double_t *m = Vtx.fP, *mV = Vtx.fC; | |
542 | ||
e7b09c95 | 543 | Bool_t noS = ( fC[35]<=0 ); // no decay length allowed |
544 | ||
545 | if( noS ){ | |
546 | TransportToDecayVertex(); | |
547 | fP[7] = 0; | |
548 | fC[28] = fC[29] = fC[30] = fC[31] = fC[32] = fC[33] = fC[35] = fC[35] = 0; | |
549 | } else { | |
550 | TransportToDS( GetDStoPoint( m ) ); | |
551 | fP[7] = -fSFromDecay; | |
552 | Convert(1); | |
553 | } | |
554 | ||
f826d409 | 555 | Double_t mAi[6]; |
706952f5 | 556 | |
446ce366 | 557 | InvertSym3( fC, mAi ); |
f826d409 | 558 | |
559 | Double_t mB[5][3]; | |
560 | ||
561 | mB[0][0] = fC[ 6]*mAi[0] + fC[ 7]*mAi[1] + fC[ 8]*mAi[3]; | |
562 | mB[0][1] = fC[ 6]*mAi[1] + fC[ 7]*mAi[2] + fC[ 8]*mAi[4]; | |
563 | mB[0][2] = fC[ 6]*mAi[3] + fC[ 7]*mAi[4] + fC[ 8]*mAi[5]; | |
564 | ||
565 | mB[1][0] = fC[10]*mAi[0] + fC[11]*mAi[1] + fC[12]*mAi[3]; | |
566 | mB[1][1] = fC[10]*mAi[1] + fC[11]*mAi[2] + fC[12]*mAi[4]; | |
567 | mB[1][2] = fC[10]*mAi[3] + fC[11]*mAi[4] + fC[12]*mAi[5]; | |
568 | ||
569 | mB[2][0] = fC[15]*mAi[0] + fC[16]*mAi[1] + fC[17]*mAi[3]; | |
570 | mB[2][1] = fC[15]*mAi[1] + fC[16]*mAi[2] + fC[17]*mAi[4]; | |
571 | mB[2][2] = fC[15]*mAi[3] + fC[16]*mAi[4] + fC[17]*mAi[5]; | |
572 | ||
573 | mB[3][0] = fC[21]*mAi[0] + fC[22]*mAi[1] + fC[23]*mAi[3]; | |
574 | mB[3][1] = fC[21]*mAi[1] + fC[22]*mAi[2] + fC[23]*mAi[4]; | |
575 | mB[3][2] = fC[21]*mAi[3] + fC[22]*mAi[4] + fC[23]*mAi[5]; | |
576 | ||
577 | mB[4][0] = fC[28]*mAi[0] + fC[29]*mAi[1] + fC[30]*mAi[3]; | |
578 | mB[4][1] = fC[28]*mAi[1] + fC[29]*mAi[2] + fC[30]*mAi[4]; | |
579 | mB[4][2] = fC[28]*mAi[3] + fC[29]*mAi[4] + fC[30]*mAi[5]; | |
580 | ||
581 | Double_t z[3] = { m[0]-fP[0], m[1]-fP[1], m[2]-fP[2] }; | |
582 | ||
583 | { | |
a65041d0 | 584 | Double_t mAVi[6] = { fC[0]-mV[0], fC[1]-mV[1], fC[2]-mV[2], |
f826d409 | 585 | fC[3]-mV[3], fC[4]-mV[4], fC[5]-mV[5] }; |
706952f5 | 586 | |
a65041d0 | 587 | if( !InvertSym3( mAVi, mAVi ) ){ |
706952f5 | 588 | |
589 | Double_t dChi2 = ( +(mAVi[0]*z[0] + mAVi[1]*z[1] + mAVi[3]*z[2])*z[0] | |
590 | +(mAVi[1]*z[0] + mAVi[2]*z[1] + mAVi[4]*z[2])*z[1] | |
a65041d0 | 591 | +(mAVi[3]*z[0] + mAVi[4]*z[1] + mAVi[5]*z[2])*z[2] ); |
706952f5 | 592 | |
593 | // Take Abs(dChi2) here. Negative value of 'det' or 'dChi2' shows that the particle | |
594 | // was not used in the production vertex fit | |
595 | ||
596 | fChi2+= TMath::Abs( dChi2 ); | |
597 | } | |
f826d409 | 598 | fNDF += 2; |
f826d409 | 599 | } |
600 | ||
601 | fP[0] = m[0]; | |
602 | fP[1] = m[1]; | |
603 | fP[2] = m[2]; | |
604 | fP[3]+= mB[0][0]*z[0] + mB[0][1]*z[1] + mB[0][2]*z[2]; | |
605 | fP[4]+= mB[1][0]*z[0] + mB[1][1]*z[1] + mB[1][2]*z[2]; | |
606 | fP[5]+= mB[2][0]*z[0] + mB[2][1]*z[1] + mB[2][2]*z[2]; | |
607 | fP[6]+= mB[3][0]*z[0] + mB[3][1]*z[1] + mB[3][2]*z[2]; | |
608 | fP[7]+= mB[4][0]*z[0] + mB[4][1]*z[1] + mB[4][2]*z[2]; | |
609 | ||
610 | Double_t d0, d1, d2; | |
611 | ||
612 | fC[0] = mV[0]; | |
613 | fC[1] = mV[1]; | |
614 | fC[2] = mV[2]; | |
615 | fC[3] = mV[3]; | |
616 | fC[4] = mV[4]; | |
617 | fC[5] = mV[5]; | |
618 | ||
619 | d0= mB[0][0]*mV[0] + mB[0][1]*mV[1] + mB[0][2]*mV[3] - fC[ 6]; | |
620 | d1= mB[0][0]*mV[1] + mB[0][1]*mV[2] + mB[0][2]*mV[4] - fC[ 7]; | |
621 | d2= mB[0][0]*mV[3] + mB[0][1]*mV[4] + mB[0][2]*mV[5] - fC[ 8]; | |
622 | ||
623 | fC[ 6]+= d0; | |
624 | fC[ 7]+= d1; | |
625 | fC[ 8]+= d2; | |
626 | fC[ 9]+= d0*mB[0][0] + d1*mB[0][1] + d2*mB[0][2]; | |
627 | ||
628 | d0= mB[1][0]*mV[0] + mB[1][1]*mV[1] + mB[1][2]*mV[3] - fC[10]; | |
629 | d1= mB[1][0]*mV[1] + mB[1][1]*mV[2] + mB[1][2]*mV[4] - fC[11]; | |
630 | d2= mB[1][0]*mV[3] + mB[1][1]*mV[4] + mB[1][2]*mV[5] - fC[12]; | |
631 | ||
632 | fC[10]+= d0; | |
633 | fC[11]+= d1; | |
634 | fC[12]+= d2; | |
635 | fC[13]+= d0*mB[0][0] + d1*mB[0][1] + d2*mB[0][2]; | |
636 | fC[14]+= d0*mB[1][0] + d1*mB[1][1] + d2*mB[1][2]; | |
637 | ||
638 | d0= mB[2][0]*mV[0] + mB[2][1]*mV[1] + mB[2][2]*mV[3] - fC[15]; | |
639 | d1= mB[2][0]*mV[1] + mB[2][1]*mV[2] + mB[2][2]*mV[4] - fC[16]; | |
640 | d2= mB[2][0]*mV[3] + mB[2][1]*mV[4] + mB[2][2]*mV[5] - fC[17]; | |
641 | ||
642 | fC[15]+= d0; | |
643 | fC[16]+= d1; | |
644 | fC[17]+= d2; | |
645 | fC[18]+= d0*mB[0][0] + d1*mB[0][1] + d2*mB[0][2]; | |
646 | fC[19]+= d0*mB[1][0] + d1*mB[1][1] + d2*mB[1][2]; | |
647 | fC[20]+= d0*mB[2][0] + d1*mB[2][1] + d2*mB[2][2]; | |
648 | ||
649 | d0= mB[3][0]*mV[0] + mB[3][1]*mV[1] + mB[3][2]*mV[3] - fC[21]; | |
650 | d1= mB[3][0]*mV[1] + mB[3][1]*mV[2] + mB[3][2]*mV[4] - fC[22]; | |
651 | d2= mB[3][0]*mV[3] + mB[3][1]*mV[4] + mB[3][2]*mV[5] - fC[23]; | |
652 | ||
653 | fC[21]+= d0; | |
654 | fC[22]+= d1; | |
655 | fC[23]+= d2; | |
656 | fC[24]+= d0*mB[0][0] + d1*mB[0][1] + d2*mB[0][2]; | |
657 | fC[25]+= d0*mB[1][0] + d1*mB[1][1] + d2*mB[1][2]; | |
658 | fC[26]+= d0*mB[2][0] + d1*mB[2][1] + d2*mB[2][2]; | |
659 | fC[27]+= d0*mB[3][0] + d1*mB[3][1] + d2*mB[3][2]; | |
660 | ||
661 | d0= mB[4][0]*mV[0] + mB[4][1]*mV[1] + mB[4][2]*mV[3] - fC[28]; | |
662 | d1= mB[4][0]*mV[1] + mB[4][1]*mV[2] + mB[4][2]*mV[4] - fC[29]; | |
663 | d2= mB[4][0]*mV[3] + mB[4][1]*mV[4] + mB[4][2]*mV[5] - fC[30]; | |
664 | ||
665 | fC[28]+= d0; | |
666 | fC[29]+= d1; | |
667 | fC[30]+= d2; | |
668 | fC[31]+= d0*mB[0][0] + d1*mB[0][1] + d2*mB[0][2]; | |
669 | fC[32]+= d0*mB[1][0] + d1*mB[1][1] + d2*mB[1][2]; | |
670 | fC[33]+= d0*mB[2][0] + d1*mB[2][1] + d2*mB[2][2]; | |
671 | fC[34]+= d0*mB[3][0] + d1*mB[3][1] + d2*mB[3][2]; | |
672 | fC[35]+= d0*mB[4][0] + d1*mB[4][1] + d2*mB[4][2]; | |
673 | ||
e7b09c95 | 674 | if( noS ){ |
675 | fP[7] = 0; | |
676 | fC[28] = fC[29] = fC[30] = fC[31] = fC[32] = fC[33] = fC[35] = fC[35] = 0; | |
677 | } else { | |
678 | TransportToDS( fP[7] ); | |
679 | Convert(0); | |
680 | } | |
681 | ||
f826d409 | 682 | fSFromDecay = 0; |
f826d409 | 683 | } |
684 | ||
685 | ||
686 | ||
e7b09c95 | 687 | void AliKFParticleBase::SetMassConstraint( Double_t Mass, Double_t SigmaMass ) |
f826d409 | 688 | { |
706952f5 | 689 | //* Set hard( SigmaMass=0 ) or soft (SigmaMass>0) mass constraint |
690 | ||
691 | Double_t m2 = Mass*Mass; // measurement, weighted by Mass | |
692 | Double_t s2 = m2*SigmaMass*SigmaMass; // sigma^2 | |
693 | ||
694 | Double_t p2 = fP[3]*fP[3] + fP[4]*fP[4] + fP[5]*fP[5]; | |
695 | Double_t e0 = TMath::Sqrt(m2+p2); | |
f826d409 | 696 | |
697 | Double_t mH[8]; | |
698 | mH[0] = mH[1] = mH[2] = 0.; | |
699 | mH[3] = -2*fP[3]; | |
700 | mH[4] = -2*fP[4]; | |
701 | mH[5] = -2*fP[5]; | |
706952f5 | 702 | mH[6] = 2*fP[6];//e0; |
f826d409 | 703 | mH[7] = 0; |
f826d409 | 704 | |
706952f5 | 705 | Double_t zeta = e0*e0 - e0*fP[6]; |
706 | zeta = m2 - (fP[6]*fP[6]-p2); | |
f826d409 | 707 | |
706952f5 | 708 | Double_t mCHt[8], s2_est=0; |
709 | for( Int_t i=0; i<8; ++i ){ | |
f826d409 | 710 | mCHt[i] = 0.0; |
711 | for (Int_t j=0;j<8;++j) mCHt[i] += Cij(i,j)*mH[j]; | |
706952f5 | 712 | s2_est += mH[i]*mCHt[i]; |
f826d409 | 713 | } |
714 | ||
706952f5 | 715 | if( s2_est<1.e-20 ) return; // calculated mass error is already 0, |
716 | // the particle can not be constrained on mass | |
717 | ||
718 | Double_t w2 = 1./( s2 + s2_est ); | |
719 | fChi2 += zeta*zeta*w2; | |
f826d409 | 720 | fNDF += 1; |
721 | for( Int_t i=0, ii=0; i<8; ++i ){ | |
706952f5 | 722 | Double_t ki = mCHt[i]*w2; |
f826d409 | 723 | fP[i]+= ki*zeta; |
724 | for(Int_t j=0;j<=i;++j) fC[ii++] -= ki*mCHt[j]; | |
725 | } | |
726 | } | |
727 | ||
728 | ||
e7b09c95 | 729 | void AliKFParticleBase::SetNoDecayLength() |
730 | { | |
731 | //* Set no decay length for resonances | |
732 | ||
733 | TransportToDecayVertex(); | |
734 | ||
735 | Double_t h[8]; | |
736 | h[0] = h[1] = h[2] = h[3] = h[4] = h[5] = h[6] = 0; | |
737 | h[7] = 1; | |
738 | ||
739 | Double_t zeta = 0 - fP[7]; | |
740 | for(Int_t i=0;i<8;++i) zeta -= h[i]*(fP[i]-fP[i]); | |
741 | ||
742 | Double_t s = fC[35]; | |
743 | if( s>1.e-20 ){ | |
744 | s = 1./s; | |
745 | fChi2 += zeta*zeta*s; | |
746 | fNDF += 1; | |
747 | for( Int_t i=0, ii=0; i<7; ++i ){ | |
748 | Double_t ki = fC[28+i]*s; | |
749 | fP[i]+= ki*zeta; | |
750 | for(Int_t j=0;j<=i;++j) fC[ii++] -= ki*fC[28+j]; | |
751 | } | |
752 | } | |
753 | fP[7] = 0; | |
754 | fC[28] = fC[29] = fC[30] = fC[31] = fC[32] = fC[33] = fC[35] = fC[35] = 0; | |
755 | } | |
756 | ||
757 | ||
f826d409 | 758 | void AliKFParticleBase::Construct( const AliKFParticleBase* vDaughters[], Int_t NDaughters, |
706952f5 | 759 | const AliKFParticleBase *Parent, Double_t Mass, Bool_t IsConstrained ) |
f826d409 | 760 | { |
761 | //* Full reconstruction in one go | |
762 | ||
763 | Int_t maxIter = 1; | |
764 | bool wasLinearized = fIsLinearized; | |
706952f5 | 765 | if( !fIsLinearized || IsConstrained ){ |
616ffc76 | 766 | //fVtxGuess[0] = fVtxGuess[1] = fVtxGuess[2] = 0; //!!!! |
767 | fVtxGuess[0] = GetX(); | |
768 | fVtxGuess[1] = GetY(); | |
769 | fVtxGuess[2] = GetZ(); | |
f826d409 | 770 | fIsLinearized = 1; |
771 | maxIter = 3; | |
772 | } | |
773 | ||
706952f5 | 774 | Double_t constraintC[6]; |
775 | ||
776 | if( IsConstrained ){ | |
777 | for(Int_t i=0;i<6;++i) constraintC[i]=fC[i]; | |
778 | } else { | |
779 | for(Int_t i=0;i<6;++i) constraintC[i]=0.; | |
780 | constraintC[0] = constraintC[2] = constraintC[5] = 100.; | |
781 | } | |
782 | ||
783 | ||
f826d409 | 784 | for( Int_t iter=0; iter<maxIter; iter++ ){ |
f826d409 | 785 | fAtProductionVertex = 0; |
786 | fSFromDecay = 0; | |
787 | fP[0] = fVtxGuess[0]; | |
788 | fP[1] = fVtxGuess[1]; | |
789 | fP[2] = fVtxGuess[2]; | |
790 | fP[3] = 0; | |
791 | fP[4] = 0; | |
792 | fP[5] = 0; | |
793 | fP[6] = 0; | |
794 | fP[7] = 0; | |
706952f5 | 795 | |
796 | for(Int_t i=0;i<6; ++i) fC[i]=constraintC[i]; | |
797 | for(Int_t i=6;i<36;++i) fC[i]=0.; | |
f826d409 | 798 | fC[35] = 1.; |
799 | ||
706952f5 | 800 | fNDF = IsConstrained ?0 :-3; |
f826d409 | 801 | fChi2 = 0.; |
802 | fQ = 0; | |
803 | ||
4bbc290d | 804 | for( Int_t itr =0; itr<NDaughters; itr++ ){ |
805 | AddDaughter( *vDaughters[itr] ); | |
806 | } | |
f826d409 | 807 | if( iter<maxIter-1){ |
808 | for( Int_t i=0; i<3; i++ ) fVtxGuess[i] = fP[i]; | |
809 | } | |
810 | } | |
811 | fIsLinearized = wasLinearized; | |
812 | ||
813 | if( Mass>=0 ) SetMassConstraint( Mass ); | |
814 | if( Parent ) SetProductionVertex( *Parent ); | |
815 | } | |
816 | ||
817 | ||
818 | void AliKFParticleBase::Convert( bool ToProduction ) | |
819 | { | |
820 | //* Tricky function - convert the particle error along its trajectory to | |
821 | //* the value which corresponds to its production/decay vertex | |
822 | //* It is done by combination of the error of decay length with the position errors | |
823 | ||
824 | Double_t fld[3]; | |
825 | { | |
826 | GetFieldValue( fP, fld ); | |
827 | const Double_t kCLight = fQ*0.000299792458; | |
828 | fld[0]*=kCLight; fld[1]*=kCLight; fld[2]*=kCLight; | |
829 | } | |
830 | ||
831 | Double_t h[6]; | |
832 | ||
833 | h[0] = fP[3]; | |
834 | h[1] = fP[4]; | |
835 | h[2] = fP[5]; | |
836 | if( ToProduction ){ h[0]=-h[0]; h[1]=-h[1]; h[2]=-h[2]; } | |
837 | h[3] = h[1]*fld[2]-h[2]*fld[1]; | |
838 | h[4] = h[2]*fld[0]-h[0]*fld[2]; | |
839 | h[5] = h[0]*fld[1]-h[1]*fld[0]; | |
840 | ||
841 | Double_t c; | |
842 | ||
843 | c = fC[28]+h[0]*fC[35]; | |
844 | fC[ 0]+= h[0]*(c+fC[28]); | |
845 | fC[28] = c; | |
846 | ||
847 | fC[ 1]+= h[1]*fC[28] + h[0]*fC[29]; | |
848 | c = fC[29]+h[1]*fC[35]; | |
849 | fC[ 2]+= h[1]*(c+fC[29]); | |
850 | fC[29] = c; | |
851 | ||
852 | fC[ 3]+= h[2]*fC[28] + h[0]*fC[30]; | |
853 | fC[ 4]+= h[2]*fC[29] + h[1]*fC[30]; | |
854 | c = fC[30]+h[2]*fC[35]; | |
855 | fC[ 5]+= h[2]*(c+fC[30]); | |
856 | fC[30] = c; | |
857 | ||
858 | fC[ 6]+= h[3]*fC[28] + h[0]*fC[31]; | |
859 | fC[ 7]+= h[3]*fC[29] + h[1]*fC[31]; | |
860 | fC[ 8]+= h[3]*fC[30] + h[2]*fC[31]; | |
861 | c = fC[31]+h[3]*fC[35]; | |
862 | fC[ 9]+= h[3]*(c+fC[31]); | |
863 | fC[31] = c; | |
864 | ||
865 | fC[10]+= h[4]*fC[28] + h[0]*fC[32]; | |
866 | fC[11]+= h[4]*fC[29] + h[1]*fC[32]; | |
867 | fC[12]+= h[4]*fC[30] + h[2]*fC[32]; | |
868 | fC[13]+= h[4]*fC[31] + h[3]*fC[32]; | |
869 | c = fC[32]+h[4]*fC[35]; | |
870 | fC[14]+= h[4]*(c+fC[32]); | |
871 | fC[32] = c; | |
872 | ||
873 | fC[15]+= h[5]*fC[28] + h[0]*fC[33]; | |
874 | fC[16]+= h[5]*fC[29] + h[1]*fC[33]; | |
875 | fC[17]+= h[5]*fC[30] + h[2]*fC[33]; | |
876 | fC[18]+= h[5]*fC[31] + h[3]*fC[33]; | |
877 | fC[19]+= h[5]*fC[32] + h[4]*fC[33]; | |
878 | c = fC[33]+h[5]*fC[35]; | |
879 | fC[20]+= h[5]*(c+fC[33]); | |
880 | fC[33] = c; | |
881 | ||
882 | fC[21]+= h[0]*fC[34]; | |
883 | fC[22]+= h[1]*fC[34]; | |
884 | fC[23]+= h[2]*fC[34]; | |
885 | fC[24]+= h[3]*fC[34]; | |
886 | fC[25]+= h[4]*fC[34]; | |
887 | fC[26]+= h[5]*fC[34]; | |
888 | } | |
889 | ||
890 | ||
891 | void AliKFParticleBase::TransportToDecayVertex() | |
892 | { | |
893 | //* Transport the particle to its decay vertex | |
894 | ||
895 | if( fSFromDecay != 0 ) TransportToDS( -fSFromDecay ); | |
896 | if( fAtProductionVertex ) Convert(0); | |
897 | fAtProductionVertex = 0; | |
898 | } | |
899 | ||
900 | void AliKFParticleBase::TransportToProductionVertex() | |
901 | { | |
902 | //* Transport the particle to its production vertex | |
616ffc76 | 903 | |
f826d409 | 904 | if( fSFromDecay != -fP[7] ) TransportToDS( -fSFromDecay-fP[7] ); |
905 | if( !fAtProductionVertex ) Convert( 1 ); | |
906 | fAtProductionVertex = 1; | |
907 | } | |
908 | ||
909 | ||
910 | void AliKFParticleBase::TransportToDS( Double_t dS ) | |
911 | { | |
912 | //* Transport the particle on dS parameter (SignedPath/Momentum) | |
616ffc76 | 913 | |
f826d409 | 914 | Transport( dS, fP, fC ); |
915 | fSFromDecay+= dS; | |
916 | } | |
917 | ||
918 | ||
919 | Double_t AliKFParticleBase::GetDStoPointLine( const Double_t xyz[] ) const | |
920 | { | |
921 | //* Get dS to a certain space point without field | |
922 | ||
923 | Double_t p2 = fP[3]*fP[3] + fP[4]*fP[4] + fP[5]*fP[5]; | |
924 | if( p2<1.e-4 ) p2 = 1; | |
925 | return ( fP[3]*(xyz[0]-fP[0]) + fP[4]*(xyz[1]-fP[1]) + fP[5]*(xyz[2]-fP[2]) )/p2; | |
926 | } | |
927 | ||
928 | ||
929 | Double_t AliKFParticleBase::GetDStoPointBz( Double_t B, const Double_t xyz[] ) | |
930 | const | |
931 | { | |
616ffc76 | 932 | |
f826d409 | 933 | //* Get dS to a certain space point for Bz field |
f826d409 | 934 | const Double_t kCLight = 0.000299792458; |
935 | Double_t bq = B*fQ*kCLight; | |
936 | Double_t pt2 = fP[3]*fP[3] + fP[4]*fP[4]; | |
937 | if( pt2<1.e-4 ) return 0; | |
938 | Double_t dx = xyz[0] - fP[0]; | |
939 | Double_t dy = xyz[1] - fP[1]; | |
940 | Double_t a = dx*fP[3]+dy*fP[4]; | |
706952f5 | 941 | Double_t dS; |
942 | ||
943 | if( TMath::Abs(bq)<1.e-8 ) dS = a/pt2; | |
944 | else dS = TMath::ATan2( bq*a, pt2 + bq*(dy*fP[3] -dx*fP[4]) )/bq; | |
945 | ||
946 | if(0){ | |
947 | ||
948 | Double_t px = fP[3]; | |
949 | Double_t py = fP[4]; | |
950 | Double_t pz = fP[5]; | |
951 | Double_t ss[2], g[2][5]; | |
952 | ||
953 | ss[0] = dS; | |
954 | ss[1] = -dS; | |
955 | for( Int_t i=0; i<2; i++){ | |
956 | Double_t bs = bq*ss[i]; | |
957 | Double_t c = TMath::Cos(bs), s = TMath::Sin(bs); | |
958 | Double_t cB,sB; | |
959 | if( TMath::Abs(bq)>1.e-8){ | |
960 | cB= (1-c)/bq; | |
961 | sB= s/bq; | |
962 | }else{ | |
bfd20868 | 963 | const Double_t kOvSqr6 = 1./TMath::Sqrt(6.); |
964 | sB = (1.-bs*kOvSqr6)*(1.+bs*kOvSqr6)*ss[i]; | |
706952f5 | 965 | cB = .5*sB*bs; |
966 | } | |
967 | g[i][0] = fP[0] + sB*px + cB*py; | |
968 | g[i][1] = fP[1] - cB*px + sB*py; | |
969 | g[i][2] = fP[2] + ss[i]*pz; | |
970 | g[i][3] = + c*px + s*py; | |
971 | g[i][4] = - s*px + c*py; | |
972 | } | |
973 | ||
974 | Int_t i=0; | |
975 | ||
976 | Double_t dMin = 1.e10; | |
977 | for( Int_t j=0; j<2; j++){ | |
978 | Double_t xx = g[j][0]-xyz[0]; | |
979 | Double_t yy = g[j][1]-xyz[1]; | |
980 | Double_t zz = g[j][2]-xyz[2]; | |
981 | Double_t d = xx*xx + yy*yy + zz*zz; | |
982 | if( d<dMin ){ | |
983 | dMin = d; | |
984 | i = j; | |
985 | } | |
986 | } | |
987 | ||
988 | dS = ss[i]; | |
989 | ||
990 | Double_t x= g[i][0], y= g[i][1], z= g[i][2], ppx= g[i][3], ppy= g[i][4]; | |
5fc72f28 | 991 | Double_t ddx = x-xyz[0]; |
992 | Double_t ddy = y-xyz[1]; | |
993 | Double_t ddz = z-xyz[2]; | |
994 | Double_t c = ddx*ppx + ddy*ppy + ddz*pz ; | |
706952f5 | 995 | Double_t pp2 = ppx*ppx + ppy*ppy + pz*pz; |
996 | if( TMath::Abs(pp2)>1.e-8 ){ | |
997 | dS+=c/pp2; | |
998 | } | |
999 | } | |
1000 | return dS; | |
f826d409 | 1001 | } |
1002 | ||
1003 | ||
1004 | void AliKFParticleBase::GetDStoParticleBz( Double_t B, const AliKFParticleBase &p, | |
616ffc76 | 1005 | Double_t &DS, Double_t &DS1 ) |
f826d409 | 1006 | const |
1007 | { | |
1008 | //* Get dS to another particle for Bz field | |
f826d409 | 1009 | Double_t px = fP[3]; |
1010 | Double_t py = fP[4]; | |
1011 | Double_t pz = fP[5]; | |
1012 | ||
1013 | Double_t px1 = p.fP[3]; | |
1014 | Double_t py1 = p.fP[4]; | |
1015 | Double_t pz1 = p.fP[5]; | |
1016 | ||
1017 | const Double_t kCLight = 0.000299792458; | |
1018 | ||
1019 | Double_t bq = B*fQ*kCLight; | |
1020 | Double_t bq1 = B*p.fQ*kCLight; | |
f826d409 | 1021 | Double_t s=0, ds=0, s1=0, ds1=0; |
1022 | ||
1023 | if( TMath::Abs(bq)>1.e-8 || TMath::Abs(bq1)>1.e-8 ){ | |
4bbc290d | 1024 | |
f826d409 | 1025 | Double_t dx = (p.fP[0] - fP[0]); |
1026 | Double_t dy = (p.fP[1] - fP[1]); | |
1027 | Double_t d2 = (dx*dx+dy*dy); | |
1028 | ||
1029 | Double_t p2 = (px *px + py *py); | |
1030 | Double_t p21 = (px1*px1 + py1*py1); | |
1031 | ||
1032 | Double_t a = (px*py1 - py*px1); | |
1033 | Double_t b = (px*px1 + py*py1); | |
1034 | ||
1035 | Double_t ldx = bq*bq1*dx - bq1*py + bq*py1 ; | |
1036 | Double_t ldy = bq*bq1*dy + bq1*px - bq*px1 ; | |
1037 | Double_t l2 = ldx*ldx + ldy*ldy; | |
1038 | ||
1039 | Double_t cS = bq1*p2 + bq*bq1*(dy* px - dx* py) - bq*b; | |
1040 | Double_t cS1= bq*p21 - bq*bq1*(dy*px1 - dx*py1) - bq1*b; | |
1041 | ||
1042 | Double_t ca = bq*bq*bq1*d2 +2*( cS + bq*bq*(py1*dx-px1*dy)) ; | |
1043 | Double_t ca1 = bq*bq1*bq1*d2 +2*( cS1 - bq1*bq1*(py*dx-px*dy)) ; | |
1044 | ||
1045 | Double_t sa = 4*l2*p2 - ca*ca; | |
1046 | Double_t sa1 = 4*l2*p21 - ca1*ca1; | |
e7b09c95 | 1047 | |
f826d409 | 1048 | if(sa<0) sa=0; |
1049 | if(sa1<0)sa1=0; | |
1050 | ||
1051 | if( TMath::Abs(bq)>1.e-8){ | |
1052 | s = TMath::ATan2( bq*( bq1*(dx*px +dy*py) + a ) , cS )/bq; | |
1053 | ds = TMath::ATan2(TMath::Sqrt(sa),ca)/bq; | |
1054 | } else { | |
1055 | s = ( (dx*px + dy*py) + (py*px1-px*py1)/bq1)/p2; | |
1056 | ds = s*s - (d2-2*(px1*dy-py1*dx)/bq1)/p2; | |
1057 | if( ds<0 ) ds = 0; | |
1058 | ds = TMath::Sqrt(ds); | |
1059 | } | |
1060 | ||
1061 | if( TMath::Abs(bq1)>1.e-8){ | |
1062 | s1 = TMath::ATan2( -bq1*( bq*(dx*px1+dy*py1) + a), cS1 )/bq1; | |
1063 | ds1 = TMath::ATan2(TMath::Sqrt(sa1),ca1)/bq1; | |
1064 | } else { | |
1065 | s1 = (-(dx*px1 + dy*py1) + (py*px1-px*py1)/bq)/p21; | |
1066 | ds1 = s1*s1 - (d2+2*(px*dy-py*dx)/bq)/p21; | |
1067 | if( ds1<0 ) ds1 = 0; | |
1068 | ds1 = TMath::Sqrt(ds1); | |
1069 | } | |
1070 | } | |
1071 | ||
f826d409 | 1072 | Double_t ss[2], ss1[2], g[2][5],g1[2][5]; |
1073 | ||
1074 | ss[0] = s + ds; | |
1075 | ss[1] = s - ds; | |
1076 | ss1[0] = s1 + ds1; | |
1077 | ss1[1] = s1 - ds1; | |
1078 | for( Int_t i=0; i<2; i++){ | |
1079 | Double_t bs = bq*ss[i]; | |
5fc72f28 | 1080 | Double_t c = TMath::Cos(bs), sss = TMath::Sin(bs); |
f826d409 | 1081 | Double_t cB,sB; |
1082 | if( TMath::Abs(bq)>1.e-8){ | |
1083 | cB= (1-c)/bq; | |
5fc72f28 | 1084 | sB= sss/bq; |
f826d409 | 1085 | }else{ |
bfd20868 | 1086 | const Double_t kOvSqr6 = 1./TMath::Sqrt(6.); |
1087 | sB = (1.-bs*kOvSqr6)*(1.+bs*kOvSqr6)*ss[i]; | |
f826d409 | 1088 | cB = .5*sB*bs; |
1089 | } | |
1090 | g[i][0] = fP[0] + sB*px + cB*py; | |
1091 | g[i][1] = fP[1] - cB*px + sB*py; | |
1092 | g[i][2] = fP[2] + ss[i]*pz; | |
5fc72f28 | 1093 | g[i][3] = + c*px + sss*py; |
1094 | g[i][4] = - sss*px + c*py; | |
f826d409 | 1095 | |
1096 | bs = bq1*ss1[i]; | |
5fc72f28 | 1097 | c = TMath::Cos(bs); sss = TMath::Sin(bs); |
f826d409 | 1098 | if( TMath::Abs(bq1)>1.e-8){ |
1099 | cB= (1-c)/bq1; | |
5fc72f28 | 1100 | sB= sss/bq1; |
f826d409 | 1101 | }else{ |
bfd20868 | 1102 | const Double_t kOvSqr6 = 1./TMath::Sqrt(6.); |
1103 | sB = (1.-bs*kOvSqr6)*(1.+bs*kOvSqr6)*ss1[i]; | |
f826d409 | 1104 | cB = .5*sB*bs; |
1105 | } | |
1106 | ||
e7b09c95 | 1107 | g1[i][0] = p.fP[0] + sB*px1 + cB*py1; |
1108 | g1[i][1] = p.fP[1] - cB*px1 + sB*py1; | |
1109 | g1[i][2] = p.fP[2] + ss[i]*pz1; | |
5fc72f28 | 1110 | g1[i][3] = + c*px1 + sss*py1; |
1111 | g1[i][4] = - sss*px1 + c*py1; | |
f826d409 | 1112 | } |
1113 | ||
1114 | Int_t i=0, i1=0; | |
1115 | ||
1116 | Double_t dMin = 1.e10; | |
1117 | for( Int_t j=0; j<2; j++){ | |
1118 | for( Int_t j1=0; j1<2; j1++){ | |
1119 | Double_t xx = g[j][0]-g1[j1][0]; | |
1120 | Double_t yy = g[j][1]-g1[j1][1]; | |
1121 | Double_t zz = g[j][2]-g1[j1][2]; | |
1122 | Double_t d = xx*xx + yy*yy + zz*zz; | |
1123 | if( d<dMin ){ | |
1124 | dMin = d; | |
1125 | i = j; | |
1126 | i1 = j1; | |
1127 | } | |
1128 | } | |
1129 | } | |
1130 | ||
1131 | DS = ss[i]; | |
1132 | DS1 = ss1[i1]; | |
91468b27 | 1133 | if(0){ |
1134 | Double_t x= g[i][0], y= g[i][1], z= g[i][2], ppx= g[i][3], ppy= g[i][4]; | |
1135 | Double_t x1=g1[i1][0], y1= g1[i1][1], z1= g1[i1][2], ppx1= g1[i1][3], ppy1= g1[i1][4]; | |
1136 | Double_t dx = x1-x; | |
1137 | Double_t dy = y1-y; | |
1138 | Double_t dz = z1-z; | |
1139 | Double_t a = ppx*ppx1 + ppy*ppy1 + pz*pz1; | |
1140 | Double_t b = dx*ppx1 + dy*ppy1 + dz*pz1; | |
1141 | Double_t c = dx*ppx + dy*ppy + dz*pz ; | |
1142 | Double_t pp2 = ppx*ppx + ppy*ppy + pz*pz; | |
1143 | Double_t pp21= ppx1*ppx1 + ppy1*ppy1 + pz1*pz1; | |
706952f5 | 1144 | Double_t det = pp2*pp21 - a*a; |
91468b27 | 1145 | if( TMath::Abs(det)>1.e-8 ){ |
1146 | DS+=(a*b-pp21*c)/det; | |
1147 | DS1+=(a*c-pp2*b)/det; | |
1148 | } | |
f826d409 | 1149 | } |
1150 | } | |
1151 | ||
1152 | ||
1153 | ||
1154 | void AliKFParticleBase::TransportCBM( Double_t dS, | |
1155 | Double_t P[], Double_t C[] ) const | |
1156 | { | |
1157 | //* Transport the particle on dS, output to P[],C[], for CBM field | |
1158 | ||
1159 | if( fQ==0 ){ | |
1160 | TransportLine( dS, P, C ); | |
1161 | return; | |
1162 | } | |
1163 | ||
1164 | const Double_t kCLight = 0.000299792458; | |
1165 | ||
1166 | Double_t c = fQ*kCLight; | |
1167 | ||
1168 | // construct coefficients | |
1169 | ||
1170 | Double_t | |
1171 | px = fP[3], | |
1172 | py = fP[4], | |
1173 | pz = fP[5]; | |
1174 | ||
1175 | 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; | |
1176 | ||
1177 | { // get field integrals | |
1178 | ||
1179 | Double_t fld[3][3]; | |
1180 | Double_t p0[3], p1[3], p2[3]; | |
1181 | ||
1182 | // line track approximation | |
1183 | ||
1184 | p0[0] = fP[0]; | |
1185 | p0[1] = fP[1]; | |
1186 | p0[2] = fP[2]; | |
1187 | ||
1188 | p2[0] = fP[0] + px*dS; | |
1189 | p2[1] = fP[1] + py*dS; | |
1190 | p2[2] = fP[2] + pz*dS; | |
1191 | ||
1192 | p1[0] = 0.5*(p0[0]+p2[0]); | |
1193 | p1[1] = 0.5*(p0[1]+p2[1]); | |
1194 | p1[2] = 0.5*(p0[2]+p2[2]); | |
1195 | ||
1196 | // first order track approximation | |
1197 | { | |
1198 | GetFieldValue( p0, fld[0] ); | |
1199 | GetFieldValue( p1, fld[1] ); | |
1200 | GetFieldValue( p2, fld[2] ); | |
1201 | ||
1202 | Double_t ssy1 = ( 7*fld[0][1] + 6*fld[1][1]-fld[2][1] )*c*dS*dS/96.; | |
1203 | Double_t ssy2 = ( fld[0][1] + 2*fld[1][1] )*c*dS*dS/6.; | |
1204 | ||
1205 | p1[0] -= ssy1*pz; | |
1206 | p1[2] += ssy1*px; | |
1207 | p2[0] -= ssy2*pz; | |
1208 | p2[2] += ssy2*px; | |
1209 | } | |
1210 | ||
1211 | GetFieldValue( p0, fld[0] ); | |
1212 | GetFieldValue( p1, fld[1] ); | |
1213 | GetFieldValue( p2, fld[2] ); | |
1214 | ||
1215 | sx = c*( fld[0][0] + 4*fld[1][0] + fld[2][0] )*dS/6.; | |
1216 | sy = c*( fld[0][1] + 4*fld[1][1] + fld[2][1] )*dS/6.; | |
1217 | sz = c*( fld[0][2] + 4*fld[1][2] + fld[2][2] )*dS/6.; | |
1218 | ||
1219 | ssx = c*( fld[0][0] + 2*fld[1][0])*dS*dS/6.; | |
1220 | ssy = c*( fld[0][1] + 2*fld[1][1])*dS*dS/6.; | |
1221 | ssz = c*( fld[0][2] + 2*fld[1][2])*dS*dS/6.; | |
1222 | ||
1223 | Double_t c2[3][3] = { { 5, -4, -1},{ 44, 80, -4},{ 11, 44, 5} }; // /=360. | |
1224 | Double_t cc2[3][3] = { { 38, 8, -4},{ 148, 208, -20},{ 3, 36, 3} }; // /=2520. | |
1225 | for(Int_t n=0; n<3; n++) | |
1226 | for(Int_t m=0; m<3; m++) | |
1227 | { | |
1228 | syz += c2[n][m]*fld[n][1]*fld[m][2]; | |
1229 | ssyz += cc2[n][m]*fld[n][1]*fld[m][2]; | |
1230 | } | |
1231 | ||
1232 | syz *= c*c*dS*dS/360.; | |
1233 | ssyz *= c*c*dS*dS*dS/2520.; | |
1234 | ||
1235 | syy = c*( fld[0][1] + 4*fld[1][1] + fld[2][1] )*dS; | |
1236 | syyy = syy*syy*syy / 1296; | |
1237 | syy = syy*syy/72; | |
1238 | ||
1239 | ssyy = ( fld[0][1]*( 38*fld[0][1] + 156*fld[1][1] - fld[2][1] )+ | |
1240 | fld[1][1]*( 208*fld[1][1] +16*fld[2][1] )+ | |
1241 | fld[2][1]*( 3*fld[2][1] ) | |
1242 | )*dS*dS*dS*c*c/2520.; | |
1243 | ssyyy = | |
1244 | ( | |
1245 | fld[0][1]*( fld[0][1]*( 85*fld[0][1] + 526*fld[1][1] - 7*fld[2][1] )+ | |
1246 | fld[1][1]*( 1376*fld[1][1] +84*fld[2][1] )+ | |
1247 | fld[2][1]*( 19*fld[2][1] ) )+ | |
1248 | fld[1][1]*( fld[1][1]*( 1376*fld[1][1] +256*fld[2][1] )+ | |
1249 | fld[2][1]*( 62*fld[2][1] ) )+ | |
1250 | fld[2][1]*fld[2][1] *( 3*fld[2][1] ) | |
1251 | )*dS*dS*dS*dS*c*c*c/90720.; | |
1252 | ||
1253 | } | |
1254 | ||
1255 | Double_t mJ[8][8]; | |
1256 | for( Int_t i=0; i<8; i++ ) for( Int_t j=0; j<8; j++) mJ[i][j]=0; | |
1257 | ||
1258 | 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; | |
1259 | 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; | |
1260 | 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; | |
1261 | ||
1262 | 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; | |
1263 | 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; | |
1264 | 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; | |
1265 | mJ[6][6] = mJ[7][7] = 1; | |
1266 | ||
1267 | P[0] = fP[0] + mJ[0][3]*px + mJ[0][4]*py + mJ[0][5]*pz; | |
1268 | P[1] = fP[1] + mJ[1][3]*px + mJ[1][4]*py + mJ[1][5]*pz; | |
1269 | P[2] = fP[2] + mJ[2][3]*px + mJ[2][4]*py + mJ[2][5]*pz; | |
1270 | P[3] = mJ[3][3]*px + mJ[3][4]*py + mJ[3][5]*pz; | |
1271 | P[4] = mJ[4][3]*px + mJ[4][4]*py + mJ[4][5]*pz; | |
1272 | P[5] = mJ[5][3]*px + mJ[5][4]*py + mJ[5][5]*pz; | |
1273 | P[6] = fP[6]; | |
1274 | P[7] = fP[7]; | |
1275 | ||
1276 | MultQSQt( mJ[0], fC, C); | |
1277 | ||
1278 | } | |
1279 | ||
1280 | ||
0d14829a | 1281 | void AliKFParticleBase::TransportBz( Double_t b, Double_t t, |
1282 | Double_t p[], Double_t e[] ) const | |
f826d409 | 1283 | { |
1284 | //* Transport the particle on dS, output to P[],C[], for Bz field | |
616ffc76 | 1285 | |
f826d409 | 1286 | const Double_t kCLight = 0.000299792458; |
5fc72f28 | 1287 | b = b*fQ*kCLight; |
0d14829a | 1288 | Double_t bs= b*t; |
f826d409 | 1289 | Double_t s = TMath::Sin(bs), c = TMath::Cos(bs); |
1290 | Double_t sB, cB; | |
616ffc76 | 1291 | if( TMath::Abs(bs)>1.e-10){ |
5fc72f28 | 1292 | sB= s/b; |
1293 | cB= (1-c)/b; | |
f826d409 | 1294 | }else{ |
bfd20868 | 1295 | const Double_t kOvSqr6 = 1./TMath::Sqrt(6.); |
0d14829a | 1296 | sB = (1.-bs*kOvSqr6)*(1.+bs*kOvSqr6)*t; |
f826d409 | 1297 | cB = .5*sB*bs; |
1298 | } | |
1299 | ||
1300 | Double_t px = fP[3]; | |
1301 | Double_t py = fP[4]; | |
1302 | Double_t pz = fP[5]; | |
1303 | ||
5fc72f28 | 1304 | p[0] = fP[0] + sB*px + cB*py; |
1305 | p[1] = fP[1] - cB*px + sB*py; | |
0d14829a | 1306 | p[2] = fP[2] + t*pz; |
5fc72f28 | 1307 | p[3] = c*px + s*py; |
1308 | p[4] = -s*px + c*py; | |
1309 | p[5] = fP[5]; | |
1310 | p[6] = fP[6]; | |
1311 | p[7] = fP[7]; | |
0d14829a | 1312 | |
1313 | /* | |
f826d409 | 1314 | Double_t mJ[8][8] = { {1,0,0, sB, cB, 0, 0, 0 }, |
616ffc76 | 1315 | {0,1,0, -cB, sB, 0, 0, 0 }, |
0d14829a | 1316 | {0,0,1, 0, 0, t, 0, 0 }, |
616ffc76 | 1317 | {0,0,0, c, s, 0, 0, 0 }, |
1318 | {0,0,0, -s, c, 0, 0, 0 }, | |
1319 | {0,0,0, 0, 0, 1, 0, 0 }, | |
1320 | {0,0,0, 0, 0, 0, 1, 0 }, | |
1321 | {0,0,0, 0, 0, 0, 0, 1 } }; | |
f826d409 | 1322 | Double_t mA[8][8]; |
1323 | for( Int_t k=0,i=0; i<8; i++) | |
1324 | for( Int_t j=0; j<=i; j++, k++ ) mA[i][j] = mA[j][i] = fC[k]; | |
1325 | ||
1326 | Double_t mJC[8][8]; | |
1327 | for( Int_t i=0; i<8; i++ ) | |
1328 | for( Int_t j=0; j<8; j++ ){ | |
1329 | mJC[i][j]=0; | |
1330 | for( Int_t k=0; k<8; k++ ) mJC[i][j]+=mJ[i][k]*mA[k][j]; | |
1331 | } | |
1332 | ||
1333 | for( Int_t k=0,i=0; i<8; i++) | |
1334 | for( Int_t j=0; j<=i; j++, k++ ){ | |
0d14829a | 1335 | e[k] = 0; |
1336 | for( Int_t l=0; l<8; l++ ) e[k]+=mJC[i][l]*mJ[j][l]; | |
f826d409 | 1337 | } |
1338 | ||
1339 | return; | |
f826d409 | 1340 | */ |
0d14829a | 1341 | |
1342 | Double_t | |
1343 | c6=fC[6], c7=fC[7], c8=fC[8], c17=fC[17], c18=fC[18], | |
1344 | c24 = fC[24], c31 = fC[31]; | |
1345 | ||
1346 | Double_t | |
1347 | cBC13 = cB*fC[13], | |
1348 | mJC13 = c7 - cB*fC[9] + sB*fC[13], | |
1349 | mJC14 = fC[11] - cBC13 + sB*fC[14], | |
1350 | mJC23 = c8 + t*c18, | |
1351 | mJC24 = fC[12] + t*fC[19], | |
1352 | mJC33 = c*fC[9] + s*fC[13], | |
1353 | mJC34 = c*fC[13] + s*fC[14], | |
1354 | mJC43 = -s*fC[9] + c*fC[13], | |
1355 | mJC44 = -s*fC[13] + c*fC[14]; | |
1356 | ||
1357 | ||
1358 | e[0]= fC[0] + 2*(sB*c6 + cB*fC[10]) + (sB*fC[9] + 2*cBC13)*sB + cB*cB*fC[14]; | |
1359 | e[1]= fC[1] - cB*c6 + sB*fC[10] + mJC13*sB + mJC14*cB; | |
1360 | e[2]= fC[2] - cB*c7 + sB*fC[11] - mJC13*cB + mJC14*sB; | |
1361 | e[3]= fC[3] + t*fC[15] + mJC23*sB + mJC24*cB; | |
1362 | e[4]= fC[4] + t*fC[16] - mJC23*cB + mJC24*sB; | |
1363 | ||
1364 | e[15]= fC[15] + c18*sB + fC[19]*cB; | |
1365 | e[16]= fC[16] - c18*cB + fC[19]*sB; | |
1366 | e[17]= c17 + fC[20]*t; | |
1367 | e[18]= c18*c + fC[19]*s; | |
1368 | e[19]= -c18*s + fC[19]*c; | |
1369 | ||
1370 | e[5]= fC[5] + (c17 + e[17] )*t; | |
1371 | ||
1372 | e[6]= c*c6 + s*fC[10] + mJC33*sB + mJC34*cB; | |
1373 | e[7]= c*c7 + s*fC[11] - mJC33*cB + mJC34*sB; | |
1374 | e[8]= c*c8 + s*fC[12] + e[18]*t; | |
1375 | e[9]= mJC33*c + mJC34*s; | |
1376 | e[10]= -s*c6 + c*fC[10] + mJC43*sB + mJC44*cB; | |
1377 | ||
1378 | ||
1379 | e[11]= -s*c7 + c*fC[11] - mJC43*cB + mJC44*sB; | |
1380 | e[12]= -s*c8 + c*fC[12] + e[19]*t; | |
1381 | e[13]= mJC43*c + mJC44*s; | |
1382 | e[14]= -mJC43*s + mJC44*c; | |
1383 | e[20]= fC[20]; | |
1384 | e[21]= fC[21] + fC[25]*cB + c24*sB; | |
1385 | e[22]= fC[22] - c24*cB + fC[25]*sB; | |
1386 | e[23]= fC[23] + fC[26]*t; | |
1387 | e[24]= c*c24 + s*fC[25]; | |
1388 | e[25]= c*fC[25] - c24*s; | |
1389 | e[26]= fC[26]; | |
1390 | e[27]= fC[27]; | |
1391 | e[28]= fC[28] + fC[32]*cB + c31*sB; | |
1392 | e[29]= fC[29] - c31*cB + fC[32]*sB; | |
1393 | e[30]= fC[30] + fC[33]*t; | |
1394 | e[31]= c*c31 + s*fC[32]; | |
1395 | e[32]= c*fC[32] - s*c31; | |
1396 | e[33]= fC[33]; | |
1397 | e[34]= fC[34]; | |
1398 | e[35]= fC[35]; | |
f826d409 | 1399 | } |
1400 | ||
1401 | ||
1402 | Double_t AliKFParticleBase::GetDistanceFromVertex( const AliKFParticleBase &Vtx ) const | |
1403 | { | |
1404 | //* Calculate distance from vertex [cm] | |
1405 | ||
1406 | return GetDistanceFromVertex( Vtx.fP ); | |
1407 | } | |
1408 | ||
1409 | Double_t AliKFParticleBase::GetDistanceFromVertex( const Double_t vtx[] ) const | |
1410 | { | |
1411 | //* Calculate distance from vertex [cm] | |
1412 | ||
1413 | Double_t mP[8], mC[36]; | |
1414 | Transport( GetDStoPoint(vtx), mP, mC ); | |
1415 | Double_t d[3]={ vtx[0]-mP[0], vtx[1]-mP[1], vtx[2]-mP[2]}; | |
1416 | return TMath::Sqrt( d[0]*d[0]+d[1]*d[1]+d[2]*d[2] ); | |
1417 | } | |
1418 | ||
616ffc76 | 1419 | Double_t AliKFParticleBase::GetDistanceFromParticle( const AliKFParticleBase &p ) |
f826d409 | 1420 | const |
1421 | { | |
616ffc76 | 1422 | //* Calculate distance to other particle [cm] |
f826d409 | 1423 | |
1424 | Double_t dS, dS1; | |
616ffc76 | 1425 | GetDStoParticle( p, dS, dS1 ); |
f826d409 | 1426 | Double_t mP[8], mC[36], mP1[8], mC1[36]; |
616ffc76 | 1427 | Transport( dS, mP, mC ); |
1428 | p.Transport( dS1, mP1, mC1 ); | |
f826d409 | 1429 | Double_t dx = mP[0]-mP1[0]; |
1430 | Double_t dy = mP[1]-mP1[1]; | |
1431 | Double_t dz = mP[2]-mP1[2]; | |
1432 | return TMath::Sqrt(dx*dx+dy*dy+dz*dz); | |
1433 | } | |
1434 | ||
1435 | Double_t AliKFParticleBase::GetDeviationFromVertex( const AliKFParticleBase &Vtx ) const | |
1436 | { | |
1437 | //* Calculate sqrt(Chi2/ndf) deviation from vertex | |
1438 | ||
1439 | return GetDeviationFromVertex( Vtx.fP, Vtx.fC ); | |
1440 | } | |
1441 | ||
1442 | ||
1443 | Double_t AliKFParticleBase::GetDeviationFromVertex( const Double_t v[], const Double_t Cv[] ) const | |
1444 | { | |
1445 | //* Calculate sqrt(Chi2/ndf) deviation from vertex | |
1446 | //* v = [xyz], Cv=[Cxx,Cxy,Cyy,Cxz,Cyz,Czz]-covariance matrix | |
1447 | ||
1448 | Double_t mP[8]; | |
1449 | Double_t mC[36]; | |
1450 | ||
1451 | Transport( GetDStoPoint(v), mP, mC ); | |
1452 | ||
1453 | Double_t d[3]={ v[0]-mP[0], v[1]-mP[1], v[2]-mP[2]}; | |
1454 | ||
1455 | Double_t sigmaS = .1+10.*TMath::Sqrt( (d[0]*d[0]+d[1]*d[1]+d[2]*d[2])/ | |
1456 | (mP[3]*mP[3]+mP[4]*mP[4]+mP[5]*mP[5]) ); | |
1457 | ||
1458 | ||
1459 | Double_t h[3] = { mP[3]*sigmaS, mP[4]*sigmaS, mP[5]*sigmaS }; | |
1460 | ||
1461 | Double_t mSi[6] = | |
1462 | { mC[0] +h[0]*h[0], | |
1463 | mC[1] +h[1]*h[0], mC[2] +h[1]*h[1], | |
1464 | mC[3] +h[2]*h[0], mC[4] +h[2]*h[1], mC[5] +h[2]*h[2] }; | |
1465 | ||
1466 | if( Cv ){ | |
1467 | mSi[0]+=Cv[0]; | |
1468 | mSi[1]+=Cv[1]; | |
1469 | mSi[2]+=Cv[2]; | |
1470 | mSi[3]+=Cv[3]; | |
1471 | mSi[4]+=Cv[4]; | |
1472 | mSi[5]+=Cv[5]; | |
1473 | } | |
1474 | ||
1475 | Double_t mS[6]; | |
1476 | ||
1477 | mS[0] = mSi[2]*mSi[5] - mSi[4]*mSi[4]; | |
1478 | mS[1] = mSi[3]*mSi[4] - mSi[1]*mSi[5]; | |
1479 | mS[2] = mSi[0]*mSi[5] - mSi[3]*mSi[3]; | |
1480 | mS[3] = mSi[1]*mSi[4] - mSi[2]*mSi[3]; | |
1481 | mS[4] = mSi[1]*mSi[3] - mSi[0]*mSi[4]; | |
1482 | mS[5] = mSi[0]*mSi[2] - mSi[1]*mSi[1]; | |
1483 | ||
1484 | Double_t s = ( mSi[0]*mS[0] + mSi[1]*mS[1] + mSi[3]*mS[3] ); | |
1485 | s = ( s > 1.E-20 ) ?1./s :0; | |
1486 | ||
1487 | return TMath::Sqrt( TMath::Abs(s*( ( mS[0]*d[0] + mS[1]*d[1] + mS[3]*d[2])*d[0] | |
1488 | +(mS[1]*d[0] + mS[2]*d[1] + mS[4]*d[2])*d[1] | |
1489 | +(mS[3]*d[0] + mS[4]*d[1] + mS[5]*d[2])*d[2] ))/2); | |
1490 | } | |
1491 | ||
1492 | ||
616ffc76 | 1493 | Double_t AliKFParticleBase::GetDeviationFromParticle( const AliKFParticleBase &p ) |
f826d409 | 1494 | const |
1495 | { | |
616ffc76 | 1496 | //* Calculate sqrt(Chi2/ndf) deviation from other particle |
f826d409 | 1497 | |
1498 | Double_t dS, dS1; | |
616ffc76 | 1499 | GetDStoParticle( p, dS, dS1 ); |
f826d409 | 1500 | Double_t mP1[8], mC1[36]; |
616ffc76 | 1501 | p.Transport( dS1, mP1, mC1 ); |
f826d409 | 1502 | |
1503 | Double_t d[3]={ fP[0]-mP1[0], fP[1]-mP1[1], fP[2]-mP1[2]}; | |
1504 | ||
1505 | Double_t sigmaS = .1+10.*TMath::Sqrt( (d[0]*d[0]+d[1]*d[1]+d[2]*d[2])/ | |
616ffc76 | 1506 | (mP1[3]*mP1[3]+mP1[4]*mP1[4]+mP1[5]*mP1[5]) ); |
f826d409 | 1507 | |
1508 | Double_t h[3] = { mP1[3]*sigmaS, mP1[4]*sigmaS, mP1[5]*sigmaS }; | |
1509 | ||
1510 | mC1[0] +=h[0]*h[0]; | |
1511 | mC1[1] +=h[1]*h[0]; | |
1512 | mC1[2] +=h[1]*h[1]; | |
1513 | mC1[3] +=h[2]*h[0]; | |
1514 | mC1[4] +=h[2]*h[1]; | |
1515 | mC1[5] +=h[2]*h[2]; | |
1516 | ||
1517 | return GetDeviationFromVertex( mP1, mC1 )*TMath::Sqrt(2./1.); | |
1518 | } | |
1519 | ||
1520 | ||
1521 | ||
de0d0ceb | 1522 | void AliKFParticleBase::SubtractFromVertex( AliKFParticleBase &Vtx ) const |
f826d409 | 1523 | { |
1524 | //* Subtract the particle from the vertex | |
de0d0ceb | 1525 | |
f826d409 | 1526 | Double_t fld[3]; |
1527 | { | |
de0d0ceb | 1528 | GetFieldValue( Vtx.fP, fld ); |
f826d409 | 1529 | const Double_t kCLight = 0.000299792458; |
1530 | fld[0]*=kCLight; fld[1]*=kCLight; fld[2]*=kCLight; | |
1531 | } | |
1532 | ||
1533 | Double_t m[8]; | |
1534 | Double_t mCm[36]; | |
f826d409 | 1535 | |
de0d0ceb | 1536 | if( Vtx.fIsLinearized ){ |
1537 | GetMeasurement( Vtx.fVtxGuess, m, mCm ); | |
1538 | } else { | |
1539 | GetMeasurement( Vtx.fP, m, mCm ); | |
f826d409 | 1540 | } |
de0d0ceb | 1541 | |
f826d409 | 1542 | Double_t mV[6]; |
1543 | ||
de0d0ceb | 1544 | mV[ 0] = mCm[ 0]; |
1545 | mV[ 1] = mCm[ 1]; | |
1546 | mV[ 2] = mCm[ 2]; | |
1547 | mV[ 3] = mCm[ 3]; | |
1548 | mV[ 4] = mCm[ 4]; | |
1549 | mV[ 5] = mCm[ 5]; | |
f826d409 | 1550 | |
1551 | //* | |
1552 | ||
1553 | Double_t mS[6]; | |
1554 | { | |
de0d0ceb | 1555 | Double_t mSi[6] = { mV[0]-Vtx.fC[0], |
1556 | mV[1]-Vtx.fC[1], mV[2]-Vtx.fC[2], | |
1557 | mV[3]-Vtx.fC[3], mV[4]-Vtx.fC[4], mV[5]-Vtx.fC[5] }; | |
f826d409 | 1558 | |
1559 | mS[0] = mSi[2]*mSi[5] - mSi[4]*mSi[4]; | |
1560 | mS[1] = mSi[3]*mSi[4] - mSi[1]*mSi[5]; | |
1561 | mS[2] = mSi[0]*mSi[5] - mSi[3]*mSi[3]; | |
1562 | mS[3] = mSi[1]*mSi[4] - mSi[2]*mSi[3]; | |
1563 | mS[4] = mSi[1]*mSi[3] - mSi[0]*mSi[4]; | |
1564 | mS[5] = mSi[0]*mSi[2] - mSi[1]*mSi[1]; | |
1565 | ||
1566 | Double_t s = ( mSi[0]*mS[0] + mSi[1]*mS[1] + mSi[3]*mS[3] ); | |
1567 | s = ( s > 1.E-20 ) ?1./s :0; | |
1568 | mS[0]*=s; | |
1569 | mS[1]*=s; | |
1570 | mS[2]*=s; | |
1571 | mS[3]*=s; | |
1572 | mS[4]*=s; | |
1573 | mS[5]*=s; | |
1574 | } | |
1575 | ||
1576 | //* Residual (measured - estimated) | |
1577 | ||
de0d0ceb | 1578 | Double_t zeta[3] = { m[0]-Vtx.fP[0], m[1]-Vtx.fP[1], m[2]-Vtx.fP[2] }; |
f826d409 | 1579 | |
1580 | //* mCHt = mCH' - D' | |
1581 | ||
1582 | Double_t mCHt0[3], mCHt1[3], mCHt2[3]; | |
1583 | ||
de0d0ceb | 1584 | mCHt0[0]=Vtx.fC[ 0] ; mCHt1[0]=Vtx.fC[ 1] ; mCHt2[0]=Vtx.fC[ 3] ; |
1585 | mCHt0[1]=Vtx.fC[ 1] ; mCHt1[1]=Vtx.fC[ 2] ; mCHt2[1]=Vtx.fC[ 4] ; | |
1586 | mCHt0[2]=Vtx.fC[ 3] ; mCHt1[2]=Vtx.fC[ 4] ; mCHt2[2]=Vtx.fC[ 5] ; | |
f826d409 | 1587 | |
1588 | //* Kalman gain K = mCH'*S | |
1589 | ||
1590 | Double_t k0[3], k1[3], k2[3]; | |
1591 | ||
1592 | for(Int_t i=0;i<3;++i){ | |
1593 | k0[i] = mCHt0[i]*mS[0] + mCHt1[i]*mS[1] + mCHt2[i]*mS[3]; | |
1594 | k1[i] = mCHt0[i]*mS[1] + mCHt1[i]*mS[2] + mCHt2[i]*mS[4]; | |
1595 | k2[i] = mCHt0[i]*mS[3] + mCHt1[i]*mS[4] + mCHt2[i]*mS[5]; | |
1596 | } | |
1597 | ||
1598 | //* New estimation of the vertex position r += K*zeta | |
1599 | ||
de0d0ceb | 1600 | Double_t dChi2 = -(mS[0]*zeta[0] + mS[1]*zeta[1] + mS[3]*zeta[2])*zeta[0] |
1601 | + (mS[1]*zeta[0] + mS[2]*zeta[1] + mS[4]*zeta[2])*zeta[1] | |
1602 | + (mS[3]*zeta[0] + mS[4]*zeta[1] + mS[5]*zeta[2])*zeta[2]; | |
1603 | ||
1604 | if( Vtx.fChi2 - dChi2 < 0 ) return; | |
1605 | ||
f826d409 | 1606 | for(Int_t i=0;i<3;++i) |
de0d0ceb | 1607 | Vtx.fP[i] -= k0[i]*zeta[0] + k1[i]*zeta[1] + k2[i]*zeta[2]; |
f826d409 | 1608 | |
1609 | //* New covariance matrix C -= K*(mCH')' | |
1610 | ||
1611 | for(Int_t i=0, k=0;i<3;++i){ | |
1612 | for(Int_t j=0;j<=i;++j,++k) | |
de0d0ceb | 1613 | Vtx.fC[k] += k0[i]*mCHt0[j] + k1[i]*mCHt1[j] + k2[i]*mCHt2[j]; |
f826d409 | 1614 | } |
1615 | ||
1616 | //* Calculate Chi^2 | |
de0d0ceb | 1617 | |
1618 | Vtx.fNDF -= 2; | |
1619 | Vtx.fChi2 -= dChi2; | |
f826d409 | 1620 | } |
1621 | ||
1622 | ||
1623 | ||
1624 | void AliKFParticleBase::TransportLine( Double_t dS, | |
1625 | Double_t P[], Double_t C[] ) const | |
1626 | { | |
1627 | //* Transport the particle as a straight line | |
1628 | ||
1629 | P[0] = fP[0] + dS*fP[3]; | |
1630 | P[1] = fP[1] + dS*fP[4]; | |
1631 | P[2] = fP[2] + dS*fP[5]; | |
1632 | P[3] = fP[3]; | |
1633 | P[4] = fP[4]; | |
1634 | P[5] = fP[5]; | |
1635 | P[6] = fP[6]; | |
1636 | P[7] = fP[7]; | |
1637 | ||
1638 | Double_t c6 = fC[ 6] + dS*fC[ 9]; | |
1639 | Double_t c11 = fC[11] + dS*fC[14]; | |
1640 | Double_t c17 = fC[17] + dS*fC[20]; | |
1641 | Double_t sc13 = dS*fC[13]; | |
1642 | Double_t sc18 = dS*fC[18]; | |
1643 | Double_t sc19 = dS*fC[19]; | |
1644 | ||
1645 | C[ 0] = fC[ 0] + dS*( fC[ 6] + c6 ); | |
1646 | C[ 2] = fC[ 2] + dS*( fC[11] + c11 ); | |
1647 | C[ 5] = fC[ 5] + dS*( fC[17] + c17 ); | |
1648 | ||
1649 | C[ 7] = fC[ 7] + sc13; | |
1650 | C[ 8] = fC[ 8] + sc18; | |
1651 | C[ 9] = fC[ 9]; | |
1652 | ||
1653 | C[12] = fC[12] + sc19; | |
1654 | ||
1655 | C[ 1] = fC[ 1] + dS*( fC[10] + C[ 7] ); | |
1656 | C[ 3] = fC[ 3] + dS*( fC[15] + C[ 8] ); | |
1657 | C[ 4] = fC[ 4] + dS*( fC[16] + C[12] ); | |
1658 | C[ 6] = c6; | |
1659 | ||
1660 | C[10] = fC[10] + sc13; | |
1661 | C[11] = c11; | |
1662 | ||
1663 | C[13] = fC[13]; | |
1664 | C[14] = fC[14]; | |
1665 | C[15] = fC[15] + sc18; | |
1666 | C[16] = fC[16] + sc19; | |
1667 | C[17] = c17; | |
1668 | ||
1669 | C[18] = fC[18]; | |
1670 | C[19] = fC[19]; | |
1671 | C[20] = fC[20]; | |
1672 | C[21] = fC[21] + dS*fC[24]; | |
1673 | C[22] = fC[22] + dS*fC[25]; | |
1674 | C[23] = fC[23] + dS*fC[26]; | |
1675 | ||
1676 | C[24] = fC[24]; | |
1677 | C[25] = fC[25]; | |
1678 | C[26] = fC[26]; | |
1679 | C[27] = fC[27]; | |
1680 | C[28] = fC[28] + dS*fC[31]; | |
1681 | C[29] = fC[29] + dS*fC[32]; | |
1682 | C[30] = fC[30] + dS*fC[33]; | |
1683 | ||
1684 | C[31] = fC[31]; | |
1685 | C[32] = fC[32]; | |
1686 | C[33] = fC[33]; | |
1687 | C[34] = fC[34]; | |
1688 | C[35] = fC[35]; | |
1689 | } | |
1690 | ||
1691 | ||
a65041d0 | 1692 | void AliKFParticleBase::ConstructGammaBz( const AliKFParticleBase &daughter1, |
1693 | const AliKFParticleBase &daughter2, double Bz ) | |
1694 | { | |
1695 | //* Create gamma | |
1696 | ||
1697 | const AliKFParticleBase *daughters[2] = { &daughter1, &daughter2}; | |
1698 | ||
1699 | double v0[3]; | |
1700 | ||
1701 | if( !fIsLinearized ){ | |
1702 | Double_t ds, ds1; | |
1703 | Double_t m[8]; | |
1704 | Double_t mCd[36]; | |
1705 | daughter1.GetDStoParticle(daughter2, ds, ds1); | |
1706 | daughter1.Transport( ds, m, mCd ); | |
1707 | v0[0] = m[0]; | |
1708 | v0[1] = m[1]; | |
1709 | v0[2] = m[2]; | |
1710 | daughter2.Transport( ds1, m, mCd ); | |
1711 | v0[0] = .5*( v0[0] + m[0] ); | |
1712 | v0[1] = .5*( v0[1] + m[1] ); | |
1713 | v0[2] = .5*( v0[2] + m[2] ); | |
1714 | } else { | |
1715 | v0[0] = fVtxGuess[0]; | |
1716 | v0[1] = fVtxGuess[1]; | |
1717 | v0[2] = fVtxGuess[2]; | |
1718 | } | |
1719 | ||
1720 | fAtProductionVertex = 0; | |
1721 | fSFromDecay = 0; | |
1722 | fP[0] = v0[0]; | |
1723 | fP[1] = v0[1]; | |
1724 | fP[2] = v0[2]; | |
1725 | fP[3] = 0; | |
1726 | fP[4] = 0; | |
1727 | fP[5] = 0; | |
1728 | fP[6] = 0; | |
1729 | fP[7] = 0; | |
1730 | ||
1731 | ||
1732 | // fit daughters to the vertex guess | |
1733 | ||
1734 | double daughterP[2][8], daughterC[2][36]; | |
1735 | double vtxMom[2][3]; | |
1736 | ||
1737 | { | |
1738 | for( int id=0; id<2; id++ ){ | |
1739 | ||
1740 | double *p = daughterP[id]; | |
1741 | double *mC = daughterC[id]; | |
1742 | ||
1743 | daughters[id]->GetMeasurement( v0, p, mC ); | |
1744 | ||
1745 | Double_t mAi[6]; | |
1746 | InvertSym3(mC, mAi ); | |
1747 | ||
1748 | Double_t mB[3][3]; | |
1749 | ||
1750 | mB[0][0] = mC[ 6]*mAi[0] + mC[ 7]*mAi[1] + mC[ 8]*mAi[3]; | |
1751 | mB[0][1] = mC[ 6]*mAi[1] + mC[ 7]*mAi[2] + mC[ 8]*mAi[4]; | |
1752 | mB[0][2] = mC[ 6]*mAi[3] + mC[ 7]*mAi[4] + mC[ 8]*mAi[5]; | |
1753 | ||
1754 | mB[1][0] = mC[10]*mAi[0] + mC[11]*mAi[1] + mC[12]*mAi[3]; | |
1755 | mB[1][1] = mC[10]*mAi[1] + mC[11]*mAi[2] + mC[12]*mAi[4]; | |
1756 | mB[1][2] = mC[10]*mAi[3] + mC[11]*mAi[4] + mC[12]*mAi[5]; | |
1757 | ||
1758 | mB[2][0] = mC[15]*mAi[0] + mC[16]*mAi[1] + mC[17]*mAi[3]; | |
1759 | mB[2][1] = mC[15]*mAi[1] + mC[16]*mAi[2] + mC[17]*mAi[4]; | |
1760 | mB[2][2] = mC[15]*mAi[3] + mC[16]*mAi[4] + mC[17]*mAi[5]; | |
1761 | ||
1762 | Double_t z[3] = { v0[0]-p[0], v0[1]-p[1], v0[2]-p[2] }; | |
1763 | ||
1764 | vtxMom[id][0] = p[3] + mB[0][0]*z[0] + mB[0][1]*z[1] + mB[0][2]*z[2]; | |
1765 | vtxMom[id][1] = p[4] + mB[1][0]*z[0] + mB[1][1]*z[1] + mB[1][2]*z[2]; | |
1766 | vtxMom[id][2] = p[5] + mB[2][0]*z[0] + mB[2][1]*z[1] + mB[2][2]*z[2]; | |
1767 | ||
1768 | daughters[id]->Transport( daughters[id]->GetDStoPoint(v0), p, mC ); | |
1769 | ||
1770 | } | |
1771 | ||
1772 | } // fit daughters to guess | |
1773 | ||
1774 | ||
1775 | // fit new vertex | |
1776 | { | |
1777 | ||
1778 | double mpx0 = vtxMom[0][0]+vtxMom[1][0]; | |
1779 | double mpy0 = vtxMom[0][1]+vtxMom[1][1]; | |
1780 | double mpt0 = TMath::Sqrt(mpx0*mpx0 + mpy0*mpy0); | |
1781 | // double a0 = TMath::ATan2(mpy0,mpx0); | |
1782 | ||
1783 | double ca0 = mpx0/mpt0; | |
1784 | double sa0 = mpy0/mpt0; | |
1785 | double r[3] = { v0[0], v0[1], v0[2] }; | |
1786 | double mC[3][3] = {{10000., 0 , 0 }, | |
1787 | {0, 10000., 0 }, | |
1788 | {0, 0, 10000. } }; | |
1789 | double chi2=0; | |
1790 | ||
1791 | for( int id=0; id<2; id++ ){ | |
1792 | const Double_t kCLight = 0.000299792458; | |
1793 | Double_t q = Bz*daughters[id]->GetQ()*kCLight; | |
1794 | Double_t px0 = vtxMom[id][0]; | |
1795 | Double_t py0 = vtxMom[id][1]; | |
1796 | Double_t pz0 = vtxMom[id][2]; | |
1797 | Double_t pt0 = TMath::Sqrt(px0*px0+py0*py0); | |
1798 | Double_t mG[3][6], mB[3], mH[3][3]; | |
1799 | // r = {vx,vy,vz}; | |
1800 | // m = {x,y,z,Px,Py,Pz}; | |
1801 | // V = daughter.C | |
1802 | // G*m + B = H*r; | |
1803 | // q*x + Py - q*vx - sin(a)*Pt = 0 | |
1804 | // q*y - Px - q*vy + cos(a)*Pt = 0 | |
1805 | // (Px*cos(a) + Py*sin(a) ) (vz -z) - Pz( cos(a)*(vx-x) + sin(a)*(vy-y)) = 0 | |
1806 | ||
1807 | mG[0][0] = q; | |
1808 | mG[0][1] = 0; | |
1809 | mG[0][2] = 0; | |
1810 | mG[0][3] = -sa0*px0/pt0; | |
1811 | mG[0][4] = 1 -sa0*py0/pt0; | |
1812 | mG[0][5] = 0; | |
1813 | mH[0][0] = q; | |
1814 | mH[0][1] = 0; | |
1815 | mH[0][2] = 0; | |
1816 | mB[0] = py0 - sa0*pt0 - mG[0][3]*px0 - mG[0][4]*py0 ; | |
1817 | ||
1818 | // q*y - Px - q*vy + cos(a)*Pt = 0 | |
1819 | ||
1820 | mG[1][0] = 0; | |
1821 | mG[1][1] = q; | |
1822 | mG[1][2] = 0; | |
1823 | mG[1][3] = -1 + ca0*px0/pt0; | |
1824 | mG[1][4] = + ca0*py0/pt0; | |
1825 | mG[1][5] = 0; | |
1826 | mH[1][0] = 0; | |
1827 | mH[1][1] = q; | |
1828 | mH[1][2] = 0; | |
1829 | mB[1] = -px0 + ca0*pt0 - mG[1][3]*px0 - mG[1][4]*py0 ; | |
1830 | ||
1831 | // (Px*cos(a) + Py*sin(a) ) (z -vz) - Pz( cos(a)*(x-vx) + sin(a)*(y-vy)) = 0 | |
1832 | ||
1833 | mG[2][0] = -pz0*ca0; | |
1834 | mG[2][1] = -pz0*sa0; | |
1835 | mG[2][2] = px0*ca0 + py0*sa0; | |
1836 | mG[2][3] = 0; | |
1837 | mG[2][4] = 0; | |
1838 | mG[2][5] = 0; | |
1839 | ||
1840 | mH[2][0] = mG[2][0]; | |
1841 | mH[2][1] = mG[2][1]; | |
1842 | mH[2][2] = mG[2][2]; | |
1843 | ||
1844 | mB[2] = 0; | |
1845 | ||
1846 | // fit the vertex | |
1847 | ||
1848 | // V = GVGt | |
1849 | ||
1850 | double mGV[3][6]; | |
1851 | double mV[6]; | |
1852 | double m[3]; | |
1853 | for( int i=0; i<3; i++ ){ | |
1854 | m[i] = mB[i]; | |
1855 | for( int k=0; k<6; k++ ) m[i]+=mG[i][k]*daughterP[id][k]; | |
1856 | } | |
1857 | for( int i=0; i<3; i++ ){ | |
1858 | for( int j=0; j<6; j++ ){ | |
1859 | mGV[i][j] = 0; | |
1860 | for( int k=0; k<6; k++ ) mGV[i][j]+=mG[i][k]*daughterC[id][ IJ(k,j) ]; | |
1861 | } | |
1862 | } | |
1863 | for( int i=0, k=0; i<3; i++ ){ | |
1864 | for( int j=0; j<=i; j++,k++ ){ | |
1865 | mV[k] = 0; | |
1866 | for( int l=0; l<6; l++ ) mV[k]+=mGV[i][l]*mG[j][l]; | |
1867 | } | |
1868 | } | |
1869 | ||
1870 | ||
1871 | //* CHt | |
1872 | ||
1873 | Double_t mCHt[3][3]; | |
1874 | Double_t mHCHt[6]; | |
1875 | Double_t mHr[3]; | |
1876 | for( int i=0; i<3; i++ ){ | |
1877 | mHr[i] = 0; | |
1878 | for( int k=0; k<3; k++ ) mHr[i]+= mH[i][k]*r[k]; | |
1879 | } | |
1880 | ||
1881 | for( int i=0; i<3; i++ ){ | |
1882 | for( int j=0; j<3; j++){ | |
1883 | mCHt[i][j] = 0; | |
1884 | for( int k=0; k<3; k++ ) mCHt[i][j]+= mC[i][k]*mH[j][k]; | |
1885 | } | |
1886 | } | |
1887 | ||
1888 | for( int i=0, k=0; i<3; i++ ){ | |
1889 | for( int j=0; j<=i; j++, k++ ){ | |
1890 | mHCHt[k] = 0; | |
1891 | for( int l=0; l<3; l++ ) mHCHt[k]+= mH[i][l]*mCHt[l][j]; | |
1892 | } | |
1893 | } | |
1894 | ||
1895 | Double_t mS[6] = { mHCHt[0]+mV[0], | |
1896 | mHCHt[1]+mV[1], mHCHt[2]+mV[2], | |
1897 | mHCHt[3]+mV[3], mHCHt[4]+mV[4], mHCHt[5]+mV[5] }; | |
1898 | ||
1899 | ||
1900 | InvertSym3(mS,mS); | |
1901 | ||
1902 | //* Residual (measured - estimated) | |
1903 | ||
1904 | Double_t zeta[3] = { m[0]-mHr[0], m[1]-mHr[1], m[2]-mHr[2] }; | |
1905 | ||
1906 | //* Kalman gain K = mCH'*S | |
1907 | ||
1908 | Double_t k[3][3]; | |
1909 | ||
1910 | for(Int_t i=0;i<3;++i){ | |
1911 | k[i][0] = mCHt[i][0]*mS[0] + mCHt[i][1]*mS[1] + mCHt[i][2]*mS[3]; | |
1912 | k[i][1] = mCHt[i][0]*mS[1] + mCHt[i][1]*mS[2] + mCHt[i][2]*mS[4]; | |
1913 | k[i][2] = mCHt[i][0]*mS[3] + mCHt[i][1]*mS[4] + mCHt[i][2]*mS[5]; | |
1914 | } | |
1915 | ||
1916 | //* New estimation of the vertex position r += K*zeta | |
1917 | ||
1918 | for(Int_t i=0;i<3;++i) | |
1919 | r[i] = r[i] + k[i][0]*zeta[0] + k[i][1]*zeta[1] + k[i][2]*zeta[2]; | |
1920 | ||
1921 | //* New covariance matrix C -= K*(mCH')' | |
1922 | ||
1923 | for(Int_t i=0;i<3;++i){ | |
1924 | for(Int_t j=0;j<=i;++j){ | |
1925 | mC[i][j] = mC[i][j] - (k[i][0]*mCHt[j][0] + k[i][1]*mCHt[j][1] + k[i][2]*mCHt[j][2]); | |
1926 | mC[j][i] = mC[i][j]; | |
1927 | } | |
1928 | } | |
1929 | ||
1930 | ||
1931 | //* Calculate Chi^2 | |
1932 | ||
1933 | chi2 += ( ( mS[0]*zeta[0] + mS[1]*zeta[1] + mS[3]*zeta[2] )*zeta[0] | |
1934 | +(mS[1]*zeta[0] + mS[2]*zeta[1] + mS[4]*zeta[2] )*zeta[1] | |
1935 | +(mS[3]*zeta[0] + mS[4]*zeta[1] + mS[5]*zeta[2] )*zeta[2] ); | |
1936 | } | |
1937 | ||
1938 | // store vertex | |
1939 | ||
1940 | fNDF = 2; | |
1941 | fChi2 = chi2; | |
1942 | for( int i=0; i<3; i++ ) fP[i] = r[i]; | |
1943 | for( int i=0,k=0; i<3; i++ ){ | |
1944 | for( int j=0; j<=i; j++,k++ ){ | |
1945 | fC[k] = mC[i][j]; | |
1946 | } | |
1947 | } | |
1948 | } | |
1949 | ||
1950 | // now fit daughters to the vertex | |
1951 | ||
1952 | fQ = 0; | |
1953 | fSFromDecay = 0; | |
1954 | ||
1955 | for(Int_t i=3;i<8;++i) fP[i]=0.; | |
1956 | for(Int_t i=6;i<36;++i) fC[i]=0.; | |
1957 | ||
1958 | ||
1959 | for( int id=0; id<2; id++ ){ | |
1960 | ||
1961 | double *p = daughterP[id]; | |
1962 | double *mC = daughterC[id]; | |
1963 | daughters[id]->GetMeasurement( v0, p, mC ); | |
1964 | ||
1965 | const Double_t *m = fP, *mV = fC; | |
1966 | ||
1967 | Double_t mAi[6]; | |
1968 | InvertSym3(mC, mAi ); | |
1969 | ||
1970 | Double_t mB[4][3]; | |
1971 | ||
1972 | mB[0][0] = mC[ 6]*mAi[0] + mC[ 7]*mAi[1] + mC[ 8]*mAi[3]; | |
1973 | mB[0][1] = mC[ 6]*mAi[1] + mC[ 7]*mAi[2] + mC[ 8]*mAi[4]; | |
1974 | mB[0][2] = mC[ 6]*mAi[3] + mC[ 7]*mAi[4] + mC[ 8]*mAi[5]; | |
1975 | ||
1976 | mB[1][0] = mC[10]*mAi[0] + mC[11]*mAi[1] + mC[12]*mAi[3]; | |
1977 | mB[1][1] = mC[10]*mAi[1] + mC[11]*mAi[2] + mC[12]*mAi[4]; | |
1978 | mB[1][2] = mC[10]*mAi[3] + mC[11]*mAi[4] + mC[12]*mAi[5]; | |
1979 | ||
1980 | mB[2][0] = mC[15]*mAi[0] + mC[16]*mAi[1] + mC[17]*mAi[3]; | |
1981 | mB[2][1] = mC[15]*mAi[1] + mC[16]*mAi[2] + mC[17]*mAi[4]; | |
1982 | mB[2][2] = mC[15]*mAi[3] + mC[16]*mAi[4] + mC[17]*mAi[5]; | |
1983 | ||
1984 | mB[3][0] = mC[21]*mAi[0] + mC[22]*mAi[1] + mC[23]*mAi[3]; | |
1985 | mB[3][1] = mC[21]*mAi[1] + mC[22]*mAi[2] + mC[23]*mAi[4]; | |
1986 | mB[3][2] = mC[21]*mAi[3] + mC[22]*mAi[4] + mC[23]*mAi[5]; | |
1987 | ||
1988 | ||
1989 | Double_t z[3] = { m[0]-p[0], m[1]-p[1], m[2]-p[2] }; | |
1990 | ||
1991 | { | |
1992 | Double_t mAV[6] = { mC[0]-mV[0], mC[1]-mV[1], mC[2]-mV[2], | |
1993 | mC[3]-mV[3], mC[4]-mV[4], mC[5]-mV[5] }; | |
1994 | ||
1995 | Double_t mAVi[6]; | |
1996 | if( !InvertSym3(mAV, mAVi) ){ | |
1997 | Double_t dChi2 = ( +(mAVi[0]*z[0] + mAVi[1]*z[1] + mAVi[3]*z[2])*z[0] | |
1998 | +(mAVi[1]*z[0] + mAVi[2]*z[1] + mAVi[4]*z[2])*z[1] | |
1999 | +(mAVi[3]*z[0] + mAVi[4]*z[1] + mAVi[5]*z[2])*z[2] ); | |
2000 | fChi2+= TMath::Abs( dChi2 ); | |
2001 | } | |
2002 | fNDF += 2; | |
2003 | } | |
2004 | ||
2005 | //* Add the daughter momentum to the particle momentum | |
2006 | ||
2007 | fP[3]+= p[3] + mB[0][0]*z[0] + mB[0][1]*z[1] + mB[0][2]*z[2]; | |
2008 | fP[4]+= p[4] + mB[1][0]*z[0] + mB[1][1]*z[1] + mB[1][2]*z[2]; | |
2009 | fP[5]+= p[5] + mB[2][0]*z[0] + mB[2][1]*z[1] + mB[2][2]*z[2]; | |
2010 | fP[6]+= p[6] + mB[3][0]*z[0] + mB[3][1]*z[1] + mB[3][2]*z[2]; | |
2011 | ||
2012 | Double_t d0, d1, d2; | |
2013 | ||
2014 | d0= mB[0][0]*mV[0] + mB[0][1]*mV[1] + mB[0][2]*mV[3] - mC[ 6]; | |
2015 | d1= mB[0][0]*mV[1] + mB[0][1]*mV[2] + mB[0][2]*mV[4] - mC[ 7]; | |
2016 | d2= mB[0][0]*mV[3] + mB[0][1]*mV[4] + mB[0][2]*mV[5] - mC[ 8]; | |
2017 | ||
2018 | //fC[6]+= mC[ 6] + d0; | |
2019 | //fC[7]+= mC[ 7] + d1; | |
2020 | //fC[8]+= mC[ 8] + d2; | |
2021 | fC[9]+= mC[ 9] + d0*mB[0][0] + d1*mB[0][1] + d2*mB[0][2]; | |
2022 | ||
2023 | d0= mB[1][0]*mV[0] + mB[1][1]*mV[1] + mB[1][2]*mV[3] - mC[10]; | |
2024 | d1= mB[1][0]*mV[1] + mB[1][1]*mV[2] + mB[1][2]*mV[4] - mC[11]; | |
2025 | d2= mB[1][0]*mV[3] + mB[1][1]*mV[4] + mB[1][2]*mV[5] - mC[12]; | |
2026 | ||
2027 | //fC[10]+= mC[10]+ d0; | |
2028 | //fC[11]+= mC[11]+ d1; | |
2029 | //fC[12]+= mC[12]+ d2; | |
2030 | fC[13]+= mC[13]+ d0*mB[0][0] + d1*mB[0][1] + d2*mB[0][2]; | |
2031 | fC[14]+= mC[14]+ d0*mB[1][0] + d1*mB[1][1] + d2*mB[1][2]; | |
2032 | ||
2033 | d0= mB[2][0]*mV[0] + mB[2][1]*mV[1] + mB[2][2]*mV[3] - mC[15]; | |
2034 | d1= mB[2][0]*mV[1] + mB[2][1]*mV[2] + mB[2][2]*mV[4] - mC[16]; | |
2035 | d2= mB[2][0]*mV[3] + mB[2][1]*mV[4] + mB[2][2]*mV[5] - mC[17]; | |
2036 | ||
2037 | //fC[15]+= mC[15]+ d0; | |
2038 | //fC[16]+= mC[16]+ d1; | |
2039 | //fC[17]+= mC[17]+ d2; | |
2040 | fC[18]+= mC[18]+ d0*mB[0][0] + d1*mB[0][1] + d2*mB[0][2]; | |
2041 | fC[19]+= mC[19]+ d0*mB[1][0] + d1*mB[1][1] + d2*mB[1][2]; | |
2042 | fC[20]+= mC[20]+ d0*mB[2][0] + d1*mB[2][1] + d2*mB[2][2]; | |
2043 | ||
2044 | d0= mB[3][0]*mV[0] + mB[3][1]*mV[1] + mB[3][2]*mV[3] - mC[21]; | |
2045 | d1= mB[3][0]*mV[1] + mB[3][1]*mV[2] + mB[3][2]*mV[4] - mC[22]; | |
2046 | d2= mB[3][0]*mV[3] + mB[3][1]*mV[4] + mB[3][2]*mV[5] - mC[23]; | |
2047 | ||
2048 | //fC[21]+= mC[21] + d0; | |
2049 | //fC[22]+= mC[22] + d1; | |
2050 | //fC[23]+= mC[23] + d2; | |
2051 | fC[24]+= mC[24] + d0*mB[0][0] + d1*mB[0][1] + d2*mB[0][2]; | |
2052 | fC[25]+= mC[25] + d0*mB[1][0] + d1*mB[1][1] + d2*mB[1][2]; | |
2053 | fC[26]+= mC[26] + d0*mB[2][0] + d1*mB[2][1] + d2*mB[2][2]; | |
2054 | fC[27]+= mC[27] + d0*mB[3][0] + d1*mB[3][1] + d2*mB[3][2]; | |
2055 | } | |
2056 | ||
2057 | SetMassConstraint(0,0); | |
2058 | ||
2059 | } | |
2060 | ||
2061 | Bool_t AliKFParticleBase::InvertSym3( const Double_t A[], Double_t Ai[] ) | |
2062 | { | |
2063 | //* Invert symmetric matric stored in low-triagonal form | |
2064 | ||
2065 | bool ret = 0; | |
2066 | double a0 = A[0], a1 = A[1], a2 = A[2], a3 = A[3]; | |
2067 | ||
2068 | Ai[0] = a2*A[5] - A[4]*A[4]; | |
2069 | Ai[1] = a3*A[4] - a1*A[5]; | |
2070 | Ai[3] = a1*A[4] - a2*a3; | |
2071 | Double_t det = (a0*Ai[0] + a1*Ai[1] + a3*Ai[3]); | |
2072 | if( det>1.e-20 ) det = 1./det; | |
2073 | else{ | |
2074 | det = 0; | |
2075 | ret = 1; | |
2076 | } | |
2077 | Ai[0] *= det; | |
2078 | Ai[1] *= det; | |
2079 | Ai[3] *= det; | |
2080 | Ai[2] = ( a0*A[5] - a3*a3 )*det; | |
2081 | Ai[4] = ( a1*a3 - a0*A[4] )*det; | |
2082 | Ai[5] = ( a0*a2 - a1*a1 )*det; | |
2083 | return ret; | |
2084 | } | |
2085 | ||
f826d409 | 2086 | void AliKFParticleBase::MultQSQt( const Double_t Q[], const Double_t S[], Double_t SOut[] ) |
2087 | { | |
2088 | //* Matrix multiplication Q*S*Q^T, Q - square matrix, S - symmetric | |
2089 | ||
2090 | const Int_t kN= 8; | |
2091 | Double_t mA[kN*kN]; | |
2092 | ||
2093 | for( Int_t i=0, ij=0; i<kN; i++ ){ | |
2094 | for( Int_t j=0; j<kN; j++, ++ij ){ | |
2095 | mA[ij] = 0 ; | |
2096 | 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]; | |
2097 | } | |
2098 | } | |
2099 | ||
2100 | for( Int_t i=0; i<kN; i++ ){ | |
2101 | for( Int_t j=0; j<=i; j++ ){ | |
2102 | Int_t ij = ( j<=i ) ? i*(i+1)/2+j :j*(j+1)/2+i; | |
2103 | SOut[ij] = 0 ; | |
2104 | for( Int_t k=0; k<kN; k++ ) SOut[ij] += Q[ i*kN+k ] * mA[ k*kN+j ]; | |
2105 | } | |
2106 | } | |
2107 | } | |
2108 | ||
2109 | ||
2110 | // 72-charachters line to define the printer border | |
2111 | //3456789012345678901234567890123456789012345678901234567890123456789012 | |
446ce366 | 2112 |