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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 | |
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22 | ClassImp(AliKFParticleBase) |
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23 | |
| 24 | |
| 25 | AliKFParticleBase::AliKFParticleBase() :fQ(0), fNDF(-3), fChi2(0), fSFromDecay(0), fAtProductionVertex(0), fIsLinearized(0) |
| 26 | { |
| 27 | //* Constructor |
| 28 | |
| 29 | Initialize(); |
| 30 | } |
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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]; |
| 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] ); |
| 74 | for( Int_t i=28; i<36; i++ ) fC[i] = 0; |
| 75 | fC[35] = 1.; |
| 76 | } |
| 77 | |
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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 | |
| 106 | Int_t AliKFParticleBase::GetMomentum( Double_t &P, Double_t &Error ) const |
| 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; |
| 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; |
| 121 | return 0; |
| 122 | } |
| 123 | return 1; |
| 124 | } |
| 125 | |
| 126 | Int_t AliKFParticleBase::GetMass( Double_t &M, Double_t &Error ) const |
| 127 | { |
| 128 | //* Calculate particle mass |
| 129 | |
| 130 | // s = sigma^2 of m2/2 |
| 131 | |
| 132 | Double_t s = ( fP[3]*fP[3]*fC[9] + fP[4]*fP[4]*fC[14] + fP[5]*fP[5]*fC[20] |
| 133 | + fP[6]*fP[6]*fC[27] |
| 134 | +2*( + fP[3]*fP[4]*fC[13] + fP[5]*(fP[3]*fC[18] + fP[4]*fC[19]) |
| 135 | - fP[6]*( fP[3]*fC[24] + fP[4]*fC[25] + fP[5]*fC[26] ) ) |
| 136 | ); |
| 137 | Double_t m2 = fP[6]*fP[6] - fP[3]*fP[3] - fP[4]*fP[4] - fP[5]*fP[5]; |
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138 | M = 0; |
| 139 | if( m2>1.e-20 ){ |
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140 | M = TMath::Sqrt(m2); |
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141 | if( s>=0 ){ |
| 142 | Error = TMath::Sqrt(s/m2); |
| 143 | return 0; |
| 144 | } |
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145 | } |
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146 | Error = 1.e20; |
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147 | return 1; |
| 148 | } |
| 149 | |
| 150 | |
| 151 | Int_t AliKFParticleBase::GetDecayLength( Double_t &L, Double_t &Error ) const |
| 152 | { |
| 153 | //* Calculate particle decay length [cm] |
| 154 | |
| 155 | Double_t x = fP[3]; |
| 156 | Double_t y = fP[4]; |
| 157 | Double_t z = fP[5]; |
| 158 | Double_t t = fP[7]; |
| 159 | Double_t x2 = x*x; |
| 160 | Double_t y2 = y*y; |
| 161 | Double_t z2 = z*z; |
| 162 | Double_t p2 = x2+y2+z2; |
| 163 | L = t*TMath::Sqrt(p2); |
| 164 | if( p2>1.e-4){ |
| 165 | Error = p2*fC[35] + t*t/p2*(x2*fC[9]+y2*fC[14]+z2*fC[20] |
| 166 | + 2*(x*y*fC[13]+x*z*fC[18]+y*z*fC[19]) ) |
| 167 | + 2*t*(x*fC[31]+y*fC[32]+z*fC[33]); |
| 168 | Error = TMath::Sqrt(TMath::Abs(Error)); |
| 169 | return 0; |
| 170 | } |
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171 | Error = 1.e20; |
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172 | return 1; |
| 173 | } |
| 174 | |
| 175 | Int_t AliKFParticleBase::GetLifeTime( Double_t &TauC, Double_t &Error ) const |
| 176 | { |
| 177 | //* Calculate particle decay time [s] |
| 178 | |
| 179 | Double_t m, dm; |
| 180 | GetMass( m, dm ); |
| 181 | Double_t cTM = (-fP[3]*fC[31] - fP[4]*fC[32] - fP[5]*fC[33] + fP[6]*fC[34]); |
| 182 | TauC = fP[7]*m; |
| 183 | Error = m*m*fC[35] + 2*fP[7]*cTM + fP[7]*fP[7]*dm*dm; |
| 184 | if( Error > 0 ){ |
| 185 | Error = TMath::Sqrt( Error ); |
| 186 | return 0; |
| 187 | } |
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188 | Error = 1.e20; |
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189 | return 1; |
| 190 | } |
| 191 | |
| 192 | |
| 193 | void AliKFParticleBase::operator +=( const AliKFParticleBase &Daughter ) |
| 194 | { |
| 195 | //* Add daughter via operator+= |
| 196 | |
| 197 | AddDaughter( Daughter ); |
| 198 | } |
| 199 | |
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200 | |
| 201 | void AliKFParticleBase::GetMeasurement( const Double_t XYZ[], Double_t m[], Double_t V[] ) const |
| 202 | { |
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203 | //* Get additional covariances V used during measurement |
| 204 | |
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205 | Double_t b[3]; |
| 206 | GetFieldValue( XYZ, b ); |
| 207 | const Double_t kCLight = 0.000299792458; |
| 208 | b[0]*=kCLight; b[1]*=kCLight; b[2]*=kCLight; |
| 209 | |
| 210 | Transport( GetDStoPoint(XYZ), m, V ); |
| 211 | |
| 212 | Double_t d[3] = { XYZ[0]-m[0], XYZ[1]-m[1], XYZ[2]-m[2] }; |
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213 | Double_t p2 = m[3]*m[3]+m[4]*m[4]+m[5]*m[5]; |
| 214 | Double_t sigmaS = (p2>1.e-4) ? ( .1+TMath::Sqrt( 100*(d[0]*d[0]+d[1]*d[1]+d[2]*d[2])) )/TMath::Sqrt(p2) : 1.; |
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215 | |
| 216 | Double_t h[6]; |
| 217 | |
| 218 | h[0] = m[3]*sigmaS; |
| 219 | h[1] = m[4]*sigmaS; |
| 220 | h[2] = m[5]*sigmaS; |
| 221 | h[3] = ( h[1]*b[2]-h[2]*b[1] )*GetQ(); |
| 222 | h[4] = ( h[2]*b[0]-h[0]*b[2] )*GetQ(); |
| 223 | h[5] = ( h[0]*b[1]-h[1]*b[0] )*GetQ(); |
| 224 | |
| 225 | //* Fit of momentum (Px,Py,Pz) to XYZ point |
| 226 | if(0){ |
| 227 | Double_t mVv[6] = |
| 228 | { V[ 0] + h[0]*h[0], |
| 229 | V[ 1] + h[0]*h[1], V[ 2] + h[1]*h[1], |
| 230 | V[ 3] + h[0]*h[2], V[ 4] + h[1]*h[2], V[ 5] + h[2]*h[2] }; |
| 231 | |
| 232 | Double_t mVvp[9]= |
| 233 | { V[ 6] + h[0]*h[3], V[ 7] + h[1]*h[3], V[ 8] + h[2]*h[3], |
| 234 | V[10] + h[0]*h[4], V[11] + h[1]*h[4], V[12] + h[2]*h[4], |
| 235 | V[15] + h[0]*h[5], V[16] + h[1]*h[5], V[17] + h[2]*h[5] }; |
| 236 | |
| 237 | Double_t mS[6] = |
| 238 | { mVv[2]*mVv[5] - mVv[4]*mVv[4], |
| 239 | mVv[3]*mVv[4] - mVv[1]*mVv[5], mVv[0]*mVv[5] - mVv[3]*mVv[3], |
| 240 | mVv[1]*mVv[4] - mVv[2]*mVv[3], mVv[1]*mVv[3] - mVv[0]*mVv[4], |
| 241 | mVv[0]*mVv[2] - mVv[1]*mVv[1] }; |
| 242 | |
| 243 | Double_t s = ( mVv[0]*mS[0] + mVv[1]*mS[1] + mVv[3]*mS[3] ); |
| 244 | s = ( s > 1.E-20 ) ?1./s :0; |
| 245 | |
| 246 | Double_t mSz[3] = { mS[0]*d[0]+mS[1]*d[1]+mS[3]*d[2], |
| 247 | mS[1]*d[0]+mS[2]*d[1]+mS[4]*d[2], |
| 248 | mS[3]*d[0]+mS[4]*d[1]+mS[5]*d[2] }; |
| 249 | |
| 250 | Double_t px = m[3] + s*( mVvp[0]*mSz[0] + mVvp[1]*mSz[1] + mVvp[2]*mSz[2] ); |
| 251 | Double_t py = m[4] + s*( mVvp[3]*mSz[0] + mVvp[4]*mSz[1] + mVvp[5]*mSz[2] ); |
| 252 | Double_t pz = m[5] + s*( mVvp[6]*mSz[0] + mVvp[7]*mSz[1] + mVvp[8]*mSz[2] ); |
| 253 | |
| 254 | h[0] = px*sigmaS; |
| 255 | h[1] = py*sigmaS; |
| 256 | h[2] = pz*sigmaS; |
| 257 | h[3] = ( h[1]*b[2]-h[2]*b[1] )*GetQ(); |
| 258 | h[4] = ( h[2]*b[0]-h[0]*b[2] )*GetQ(); |
| 259 | h[5] = ( h[0]*b[1]-h[1]*b[0] )*GetQ(); |
| 260 | } |
| 261 | |
| 262 | V[ 0]+= h[0]*h[0]; |
| 263 | V[ 1]+= h[1]*h[0]; |
| 264 | V[ 2]+= h[1]*h[1]; |
| 265 | V[ 3]+= h[2]*h[0]; |
| 266 | V[ 4]+= h[2]*h[1]; |
| 267 | V[ 5]+= h[2]*h[2]; |
| 268 | |
| 269 | V[ 6]+= h[3]*h[0]; |
| 270 | V[ 7]+= h[3]*h[1]; |
| 271 | V[ 8]+= h[3]*h[2]; |
| 272 | V[ 9]+= h[3]*h[3]; |
| 273 | |
| 274 | V[10]+= h[4]*h[0]; |
| 275 | V[11]+= h[4]*h[1]; |
| 276 | V[12]+= h[4]*h[2]; |
| 277 | V[13]+= h[4]*h[3]; |
| 278 | V[14]+= h[4]*h[4]; |
| 279 | |
| 280 | V[15]+= h[5]*h[0]; |
| 281 | V[16]+= h[5]*h[1]; |
| 282 | V[17]+= h[5]*h[2]; |
| 283 | V[18]+= h[5]*h[3]; |
| 284 | V[19]+= h[5]*h[4]; |
| 285 | V[20]+= h[5]*h[5]; |
| 286 | } |
| 287 | |
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288 | |
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289 | void AliKFParticleBase::AddDaughter( const AliKFParticleBase &Daughter ) |
| 290 | { |
| 291 | //* Add daughter |
| 292 | |
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293 | if( fNDF<-1 ){ // first daughter -> just copy |
| 294 | fNDF = -1; |
| 295 | fQ = Daughter.GetQ(); |
| 296 | for( Int_t i=0; i<7; i++) fP[i] = Daughter.fP[i]; |
| 297 | for( Int_t i=0; i<28; i++) fC[i] = Daughter.fC[i]; |
| 298 | fSFromDecay = 0; |
| 299 | return; |
| 300 | } |
| 301 | |
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302 | TransportToDecayVertex(); |
| 303 | |
| 304 | Double_t b[3]; |
| 305 | Int_t maxIter = 1; |
| 306 | |
| 307 | if( !fIsLinearized ){ |
| 308 | if( fNDF==-1 ){ |
| 309 | Double_t ds, ds1; |
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310 | GetDStoParticle(Daughter, ds, ds1); |
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311 | TransportToDS( ds ); |
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312 | Double_t m[8]; |
| 313 | Double_t mCd[36]; |
| 314 | Daughter.Transport( ds1, m, mCd ); |
| 315 | fVtxGuess[0] = .5*( fP[0] + m[0] ); |
| 316 | fVtxGuess[1] = .5*( fP[1] + m[1] ); |
| 317 | fVtxGuess[2] = .5*( fP[2] + m[2] ); |
| 318 | } else { |
| 319 | fVtxGuess[0] = fP[0]; |
| 320 | fVtxGuess[1] = fP[1]; |
| 321 | fVtxGuess[2] = fP[2]; |
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322 | } |
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323 | maxIter = 3; |
| 324 | } |
| 325 | |
| 326 | for( Int_t iter=0; iter<maxIter; iter++ ){ |
| 327 | |
| 328 | { |
| 329 | GetFieldValue( fVtxGuess, b ); |
| 330 | const Double_t kCLight = 0.000299792458; |
| 331 | b[0]*=kCLight; b[1]*=kCLight; b[2]*=kCLight; |
| 332 | } |
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333 | |
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334 | Double_t *ffP = fP, *ffC = fC, tmpP[8], tmpC[36]; |
| 335 | if( fNDF==-1 ){ |
| 336 | GetMeasurement( fVtxGuess, tmpP, tmpC ); |
| 337 | ffP = tmpP; |
| 338 | ffC = tmpC; |
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339 | } |
| 340 | |
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341 | Double_t m[8], mV[36]; |
| 342 | if( Daughter.fC[35]>0 ){ |
| 343 | Daughter.GetMeasurement( fVtxGuess, m, mV ); |
| 344 | } else { |
| 345 | for( Int_t i=0; i<8; i++ ) m[i] = Daughter.fP[i]; |
| 346 | for( Int_t i=0; i<36; i++ ) mV[i] = Daughter.fC[i]; |
| 347 | } |
| 348 | |
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349 | //* |
| 350 | |
| 351 | Double_t mS[6]; |
| 352 | { |
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353 | Double_t mSi[6] = { ffC[0]+mV[0], |
| 354 | ffC[1]+mV[1], ffC[2]+mV[2], |
| 355 | ffC[3]+mV[3], ffC[4]+mV[4], ffC[5]+mV[5] }; |
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356 | |
| 357 | mS[0] = mSi[2]*mSi[5] - mSi[4]*mSi[4]; |
| 358 | mS[1] = mSi[3]*mSi[4] - mSi[1]*mSi[5]; |
| 359 | mS[2] = mSi[0]*mSi[5] - mSi[3]*mSi[3]; |
| 360 | mS[3] = mSi[1]*mSi[4] - mSi[2]*mSi[3]; |
| 361 | mS[4] = mSi[1]*mSi[3] - mSi[0]*mSi[4]; |
| 362 | mS[5] = mSi[0]*mSi[2] - mSi[1]*mSi[1]; |
| 363 | |
| 364 | Double_t s = ( mSi[0]*mS[0] + mSi[1]*mS[1] + mSi[3]*mS[3] ); |
| 365 | s = ( s > 1.E-20 ) ?1./s :0; |
| 366 | mS[0]*=s; |
| 367 | mS[1]*=s; |
| 368 | mS[2]*=s; |
| 369 | mS[3]*=s; |
| 370 | mS[4]*=s; |
| 371 | mS[5]*=s; |
| 372 | } |
| 373 | |
| 374 | //* Residual (measured - estimated) |
| 375 | |
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376 | Double_t zeta[3] = { m[0]-ffP[0], m[1]-ffP[1], m[2]-ffP[2] }; |
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377 | |
| 378 | //* CHt = CH' - D' |
| 379 | |
| 380 | Double_t mCHt0[7], mCHt1[7], mCHt2[7]; |
| 381 | |
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382 | mCHt0[0]=ffC[ 0] ; mCHt1[0]=ffC[ 1] ; mCHt2[0]=ffC[ 3] ; |
| 383 | mCHt0[1]=ffC[ 1] ; mCHt1[1]=ffC[ 2] ; mCHt2[1]=ffC[ 4] ; |
| 384 | mCHt0[2]=ffC[ 3] ; mCHt1[2]=ffC[ 4] ; mCHt2[2]=ffC[ 5] ; |
| 385 | mCHt0[3]=ffC[ 6]-mV[ 6]; mCHt1[3]=ffC[ 7]-mV[ 7]; mCHt2[3]=ffC[ 8]-mV[ 8]; |
| 386 | mCHt0[4]=ffC[10]-mV[10]; mCHt1[4]=ffC[11]-mV[11]; mCHt2[4]=ffC[12]-mV[12]; |
| 387 | mCHt0[5]=ffC[15]-mV[15]; mCHt1[5]=ffC[16]-mV[16]; mCHt2[5]=ffC[17]-mV[17]; |
| 388 | mCHt0[6]=ffC[21]-mV[21]; mCHt1[6]=ffC[22]-mV[22]; mCHt2[6]=ffC[23]-mV[23]; |
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389 | |
| 390 | //* Kalman gain K = mCH'*S |
| 391 | |
| 392 | Double_t k0[7], k1[7], k2[7]; |
| 393 | |
| 394 | for(Int_t i=0;i<7;++i){ |
| 395 | k0[i] = mCHt0[i]*mS[0] + mCHt1[i]*mS[1] + mCHt2[i]*mS[3]; |
| 396 | k1[i] = mCHt0[i]*mS[1] + mCHt1[i]*mS[2] + mCHt2[i]*mS[4]; |
| 397 | k2[i] = mCHt0[i]*mS[3] + mCHt1[i]*mS[4] + mCHt2[i]*mS[5]; |
| 398 | } |
| 399 | |
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400 | //* New estimation of the vertex position |
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401 | |
| 402 | if( iter<maxIter-1 ){ |
| 403 | for(Int_t i=0; i<3; ++i) |
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404 | fVtxGuess[i]= ffP[i] + k0[i]*zeta[0]+k1[i]*zeta[1]+k2[i]*zeta[2]; |
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405 | continue; |
| 406 | } |
| 407 | |
| 408 | // last itearation -> update the particle |
| 409 | |
| 410 | //* Add the daughter momentum to the particle momentum |
| 411 | |
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412 | ffP[ 3] += m[ 3]; |
| 413 | ffP[ 4] += m[ 4]; |
| 414 | ffP[ 5] += m[ 5]; |
| 415 | ffP[ 6] += m[ 6]; |
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416 | |
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417 | ffC[ 9] += mV[ 9]; |
| 418 | ffC[13] += mV[13]; |
| 419 | ffC[14] += mV[14]; |
| 420 | ffC[18] += mV[18]; |
| 421 | ffC[19] += mV[19]; |
| 422 | ffC[20] += mV[20]; |
| 423 | ffC[24] += mV[24]; |
| 424 | ffC[25] += mV[25]; |
| 425 | ffC[26] += mV[26]; |
| 426 | ffC[27] += mV[27]; |
| f826d409 |
427 | |
| 428 | //* New estimation of the vertex position r += K*zeta |
| 429 | |
| 430 | for(Int_t i=0;i<7;++i) |
| 616ffc76 |
431 | fP[i] = ffP[i] + k0[i]*zeta[0] + k1[i]*zeta[1] + k2[i]*zeta[2]; |
| f826d409 |
432 | |
| 433 | //* New covariance matrix C -= K*(mCH')' |
| 4bbc290d |
434 | |
| f826d409 |
435 | for(Int_t i=0, k=0;i<7;++i){ |
| 436 | for(Int_t j=0;j<=i;++j,++k) |
| 616ffc76 |
437 | fC[k] = ffC[k] - (k0[i]*mCHt0[j] + k1[i]*mCHt1[j] + k2[i]*mCHt2[j] ); |
| f826d409 |
438 | } |
| 439 | |
| 440 | //* Calculate Chi^2 |
| 441 | |
| 442 | fNDF += 2; |
| 443 | fQ += Daughter.GetQ(); |
| 444 | fSFromDecay = 0; |
| 445 | fChi2 += (mS[0]*zeta[0] + mS[1]*zeta[1] + mS[3]*zeta[2])*zeta[0] |
| 446 | + (mS[1]*zeta[0] + mS[2]*zeta[1] + mS[4]*zeta[2])*zeta[1] |
| 447 | + (mS[3]*zeta[0] + mS[4]*zeta[1] + mS[5]*zeta[2])*zeta[2]; |
| 448 | } |
| 449 | } |
| 450 | |
| f826d409 |
451 | void AliKFParticleBase::SetProductionVertex( const AliKFParticleBase &Vtx ) |
| 452 | { |
| 453 | //* Set production vertex for the particle |
| 454 | |
| 455 | const Double_t *m = Vtx.fP, *mV = Vtx.fC; |
| 456 | |
| e7b09c95 |
457 | Bool_t noS = ( fC[35]<=0 ); // no decay length allowed |
| 458 | |
| 459 | if( noS ){ |
| 460 | TransportToDecayVertex(); |
| 461 | fP[7] = 0; |
| 462 | fC[28] = fC[29] = fC[30] = fC[31] = fC[32] = fC[33] = fC[35] = fC[35] = 0; |
| 463 | } else { |
| 464 | TransportToDS( GetDStoPoint( m ) ); |
| 465 | fP[7] = -fSFromDecay; |
| 466 | Convert(1); |
| 467 | } |
| 468 | |
| f826d409 |
469 | |
| 470 | Double_t mAi[6]; |
| 471 | mAi[0] = fC[4]*fC[4] - fC[2]*fC[5]; |
| 472 | mAi[1] = fC[1]*fC[5] - fC[3]*fC[4]; |
| 473 | mAi[3] = fC[2]*fC[3] - fC[1]*fC[4]; |
| 474 | Double_t det = 1./(fC[0]*mAi[0] + fC[1]*mAi[1] + fC[3]*mAi[3]); |
| 475 | mAi[0] *= det; |
| 476 | mAi[1] *= det; |
| 477 | mAi[3] *= det; |
| 478 | mAi[2] = ( fC[3]*fC[3] - fC[0]*fC[5] )*det; |
| 479 | mAi[4] = ( fC[0]*fC[4] - fC[1]*fC[3] )*det; |
| 480 | mAi[5] = ( fC[1]*fC[1] - fC[0]*fC[2] )*det; |
| 481 | |
| 482 | Double_t mB[5][3]; |
| 483 | |
| 484 | mB[0][0] = fC[ 6]*mAi[0] + fC[ 7]*mAi[1] + fC[ 8]*mAi[3]; |
| 485 | mB[0][1] = fC[ 6]*mAi[1] + fC[ 7]*mAi[2] + fC[ 8]*mAi[4]; |
| 486 | mB[0][2] = fC[ 6]*mAi[3] + fC[ 7]*mAi[4] + fC[ 8]*mAi[5]; |
| 487 | |
| 488 | mB[1][0] = fC[10]*mAi[0] + fC[11]*mAi[1] + fC[12]*mAi[3]; |
| 489 | mB[1][1] = fC[10]*mAi[1] + fC[11]*mAi[2] + fC[12]*mAi[4]; |
| 490 | mB[1][2] = fC[10]*mAi[3] + fC[11]*mAi[4] + fC[12]*mAi[5]; |
| 491 | |
| 492 | mB[2][0] = fC[15]*mAi[0] + fC[16]*mAi[1] + fC[17]*mAi[3]; |
| 493 | mB[2][1] = fC[15]*mAi[1] + fC[16]*mAi[2] + fC[17]*mAi[4]; |
| 494 | mB[2][2] = fC[15]*mAi[3] + fC[16]*mAi[4] + fC[17]*mAi[5]; |
| 495 | |
| 496 | mB[3][0] = fC[21]*mAi[0] + fC[22]*mAi[1] + fC[23]*mAi[3]; |
| 497 | mB[3][1] = fC[21]*mAi[1] + fC[22]*mAi[2] + fC[23]*mAi[4]; |
| 498 | mB[3][2] = fC[21]*mAi[3] + fC[22]*mAi[4] + fC[23]*mAi[5]; |
| 499 | |
| 500 | mB[4][0] = fC[28]*mAi[0] + fC[29]*mAi[1] + fC[30]*mAi[3]; |
| 501 | mB[4][1] = fC[28]*mAi[1] + fC[29]*mAi[2] + fC[30]*mAi[4]; |
| 502 | mB[4][2] = fC[28]*mAi[3] + fC[29]*mAi[4] + fC[30]*mAi[5]; |
| 503 | |
| 504 | Double_t z[3] = { m[0]-fP[0], m[1]-fP[1], m[2]-fP[2] }; |
| 505 | |
| 506 | { |
| 507 | Double_t mAV[6] = { fC[0]-mV[0], fC[1]-mV[1], fC[2]-mV[2], |
| 508 | fC[3]-mV[3], fC[4]-mV[4], fC[5]-mV[5] }; |
| 509 | Double_t mAVi[6]; |
| 510 | mAVi[0] = mAV[4]*mAV[4] - mAV[2]*mAV[5]; |
| 511 | mAVi[1] = mAV[1]*mAV[5] - mAV[3]*mAV[4]; |
| 512 | mAVi[2] = mAV[3]*mAV[3] - mAV[0]*mAV[5] ; |
| 513 | mAVi[3] = mAV[2]*mAV[3] - mAV[1]*mAV[4]; |
| 514 | mAVi[4] = mAV[0]*mAV[4] - mAV[1]*mAV[3] ; |
| 515 | mAVi[5] = mAV[1]*mAV[1] - mAV[0]*mAV[2] ; |
| 516 | |
| e7b09c95 |
517 | det = ( mAV[0]*mAVi[0] + mAV[1]*mAVi[1] + mAV[3]*mAVi[3] ); |
| 518 | if( det>1.e-8 ) det = 1./det; |
| f826d409 |
519 | |
| 520 | fNDF += 2; |
| 521 | fChi2 += |
| 522 | ( +(mAVi[0]*z[0] + mAVi[1]*z[1] + mAVi[3]*z[2])*z[0] |
| 523 | +(mAVi[1]*z[0] + mAVi[2]*z[1] + mAVi[4]*z[2])*z[1] |
| 524 | +(mAVi[3]*z[0] + mAVi[4]*z[1] + mAVi[5]*z[2])*z[2] )*det; |
| 525 | } |
| 526 | |
| 527 | fP[0] = m[0]; |
| 528 | fP[1] = m[1]; |
| 529 | fP[2] = m[2]; |
| 530 | fP[3]+= mB[0][0]*z[0] + mB[0][1]*z[1] + mB[0][2]*z[2]; |
| 531 | fP[4]+= mB[1][0]*z[0] + mB[1][1]*z[1] + mB[1][2]*z[2]; |
| 532 | fP[5]+= mB[2][0]*z[0] + mB[2][1]*z[1] + mB[2][2]*z[2]; |
| 533 | fP[6]+= mB[3][0]*z[0] + mB[3][1]*z[1] + mB[3][2]*z[2]; |
| 534 | fP[7]+= mB[4][0]*z[0] + mB[4][1]*z[1] + mB[4][2]*z[2]; |
| 535 | |
| 536 | Double_t d0, d1, d2; |
| 537 | |
| 538 | fC[0] = mV[0]; |
| 539 | fC[1] = mV[1]; |
| 540 | fC[2] = mV[2]; |
| 541 | fC[3] = mV[3]; |
| 542 | fC[4] = mV[4]; |
| 543 | fC[5] = mV[5]; |
| 544 | |
| 545 | d0= mB[0][0]*mV[0] + mB[0][1]*mV[1] + mB[0][2]*mV[3] - fC[ 6]; |
| 546 | d1= mB[0][0]*mV[1] + mB[0][1]*mV[2] + mB[0][2]*mV[4] - fC[ 7]; |
| 547 | d2= mB[0][0]*mV[3] + mB[0][1]*mV[4] + mB[0][2]*mV[5] - fC[ 8]; |
| 548 | |
| 549 | fC[ 6]+= d0; |
| 550 | fC[ 7]+= d1; |
| 551 | fC[ 8]+= d2; |
| 552 | fC[ 9]+= d0*mB[0][0] + d1*mB[0][1] + d2*mB[0][2]; |
| 553 | |
| 554 | d0= mB[1][0]*mV[0] + mB[1][1]*mV[1] + mB[1][2]*mV[3] - fC[10]; |
| 555 | d1= mB[1][0]*mV[1] + mB[1][1]*mV[2] + mB[1][2]*mV[4] - fC[11]; |
| 556 | d2= mB[1][0]*mV[3] + mB[1][1]*mV[4] + mB[1][2]*mV[5] - fC[12]; |
| 557 | |
| 558 | fC[10]+= d0; |
| 559 | fC[11]+= d1; |
| 560 | fC[12]+= d2; |
| 561 | fC[13]+= d0*mB[0][0] + d1*mB[0][1] + d2*mB[0][2]; |
| 562 | fC[14]+= d0*mB[1][0] + d1*mB[1][1] + d2*mB[1][2]; |
| 563 | |
| 564 | d0= mB[2][0]*mV[0] + mB[2][1]*mV[1] + mB[2][2]*mV[3] - fC[15]; |
| 565 | d1= mB[2][0]*mV[1] + mB[2][1]*mV[2] + mB[2][2]*mV[4] - fC[16]; |
| 566 | d2= mB[2][0]*mV[3] + mB[2][1]*mV[4] + mB[2][2]*mV[5] - fC[17]; |
| 567 | |
| 568 | fC[15]+= d0; |
| 569 | fC[16]+= d1; |
| 570 | fC[17]+= d2; |
| 571 | fC[18]+= d0*mB[0][0] + d1*mB[0][1] + d2*mB[0][2]; |
| 572 | fC[19]+= d0*mB[1][0] + d1*mB[1][1] + d2*mB[1][2]; |
| 573 | fC[20]+= d0*mB[2][0] + d1*mB[2][1] + d2*mB[2][2]; |
| 574 | |
| 575 | d0= mB[3][0]*mV[0] + mB[3][1]*mV[1] + mB[3][2]*mV[3] - fC[21]; |
| 576 | d1= mB[3][0]*mV[1] + mB[3][1]*mV[2] + mB[3][2]*mV[4] - fC[22]; |
| 577 | d2= mB[3][0]*mV[3] + mB[3][1]*mV[4] + mB[3][2]*mV[5] - fC[23]; |
| 578 | |
| 579 | fC[21]+= d0; |
| 580 | fC[22]+= d1; |
| 581 | fC[23]+= d2; |
| 582 | fC[24]+= d0*mB[0][0] + d1*mB[0][1] + d2*mB[0][2]; |
| 583 | fC[25]+= d0*mB[1][0] + d1*mB[1][1] + d2*mB[1][2]; |
| 584 | fC[26]+= d0*mB[2][0] + d1*mB[2][1] + d2*mB[2][2]; |
| 585 | fC[27]+= d0*mB[3][0] + d1*mB[3][1] + d2*mB[3][2]; |
| 586 | |
| 587 | d0= mB[4][0]*mV[0] + mB[4][1]*mV[1] + mB[4][2]*mV[3] - fC[28]; |
| 588 | d1= mB[4][0]*mV[1] + mB[4][1]*mV[2] + mB[4][2]*mV[4] - fC[29]; |
| 589 | d2= mB[4][0]*mV[3] + mB[4][1]*mV[4] + mB[4][2]*mV[5] - fC[30]; |
| 590 | |
| 591 | fC[28]+= d0; |
| 592 | fC[29]+= d1; |
| 593 | fC[30]+= d2; |
| 594 | fC[31]+= d0*mB[0][0] + d1*mB[0][1] + d2*mB[0][2]; |
| 595 | fC[32]+= d0*mB[1][0] + d1*mB[1][1] + d2*mB[1][2]; |
| 596 | fC[33]+= d0*mB[2][0] + d1*mB[2][1] + d2*mB[2][2]; |
| 597 | fC[34]+= d0*mB[3][0] + d1*mB[3][1] + d2*mB[3][2]; |
| 598 | fC[35]+= d0*mB[4][0] + d1*mB[4][1] + d2*mB[4][2]; |
| 599 | |
| e7b09c95 |
600 | if( noS ){ |
| 601 | fP[7] = 0; |
| 602 | fC[28] = fC[29] = fC[30] = fC[31] = fC[32] = fC[33] = fC[35] = fC[35] = 0; |
| 603 | } else { |
| 604 | TransportToDS( fP[7] ); |
| 605 | Convert(0); |
| 606 | } |
| 607 | |
| f826d409 |
608 | fSFromDecay = 0; |
| f826d409 |
609 | } |
| 610 | |
| 611 | |
| 612 | |
| 613 | |
| e7b09c95 |
614 | void AliKFParticleBase::SetMassConstraint( Double_t Mass, Double_t SigmaMass ) |
| f826d409 |
615 | { |
| 616 | //* Set hard mass constraint |
| 617 | |
| 618 | Double_t mH[8]; |
| 619 | mH[0] = mH[1] = mH[2] = 0.; |
| 620 | mH[3] = -2*fP[3]; |
| 621 | mH[4] = -2*fP[4]; |
| 622 | mH[5] = -2*fP[5]; |
| 623 | mH[6] = 2*fP[6]; |
| 624 | mH[7] = 0; |
| 625 | Double_t m2 = ( fP[6]*fP[6] |
| 626 | - fP[3]*fP[3] - fP[4]*fP[4] - fP[5]*fP[5] ); |
| 627 | |
| 628 | Double_t zeta = Mass*Mass - m2; |
| 629 | for(Int_t i=0;i<8;++i) zeta -= mH[i]*(fP[i]-fP[i]); |
| 630 | |
| e7b09c95 |
631 | Double_t s = 4*Mass*Mass*SigmaMass*SigmaMass; |
| f826d409 |
632 | Double_t mCHt[8]; |
| 633 | for (Int_t i=0;i<8;++i ){ |
| 634 | mCHt[i] = 0.0; |
| 635 | for (Int_t j=0;j<8;++j) mCHt[i] += Cij(i,j)*mH[j]; |
| 636 | s += mH[i]*mCHt[i]; |
| 637 | } |
| 638 | |
| 639 | if( s<1.e-20 ) return; |
| 640 | s = 1./s; |
| 641 | fChi2 += zeta*zeta*s; |
| 642 | fNDF += 1; |
| 643 | for( Int_t i=0, ii=0; i<8; ++i ){ |
| 644 | Double_t ki = mCHt[i]*s; |
| 645 | fP[i]+= ki*zeta; |
| 646 | for(Int_t j=0;j<=i;++j) fC[ii++] -= ki*mCHt[j]; |
| 647 | } |
| 648 | } |
| 649 | |
| 650 | |
| e7b09c95 |
651 | void AliKFParticleBase::SetNoDecayLength() |
| 652 | { |
| 653 | //* Set no decay length for resonances |
| 654 | |
| 655 | TransportToDecayVertex(); |
| 656 | |
| 657 | Double_t h[8]; |
| 658 | h[0] = h[1] = h[2] = h[3] = h[4] = h[5] = h[6] = 0; |
| 659 | h[7] = 1; |
| 660 | |
| 661 | Double_t zeta = 0 - fP[7]; |
| 662 | for(Int_t i=0;i<8;++i) zeta -= h[i]*(fP[i]-fP[i]); |
| 663 | |
| 664 | Double_t s = fC[35]; |
| 665 | if( s>1.e-20 ){ |
| 666 | s = 1./s; |
| 667 | fChi2 += zeta*zeta*s; |
| 668 | fNDF += 1; |
| 669 | for( Int_t i=0, ii=0; i<7; ++i ){ |
| 670 | Double_t ki = fC[28+i]*s; |
| 671 | fP[i]+= ki*zeta; |
| 672 | for(Int_t j=0;j<=i;++j) fC[ii++] -= ki*fC[28+j]; |
| 673 | } |
| 674 | } |
| 675 | fP[7] = 0; |
| 676 | fC[28] = fC[29] = fC[30] = fC[31] = fC[32] = fC[33] = fC[35] = fC[35] = 0; |
| 677 | } |
| 678 | |
| 679 | |
| f826d409 |
680 | void AliKFParticleBase::Construct( const AliKFParticleBase* vDaughters[], Int_t NDaughters, |
| 4bbc290d |
681 | const AliKFParticleBase *Parent, Double_t Mass ) |
| f826d409 |
682 | { |
| 683 | //* Full reconstruction in one go |
| 684 | |
| 685 | Int_t maxIter = 1; |
| 686 | bool wasLinearized = fIsLinearized; |
| 687 | if( !fIsLinearized ){ |
| 616ffc76 |
688 | //fVtxGuess[0] = fVtxGuess[1] = fVtxGuess[2] = 0; //!!!! |
| 689 | fVtxGuess[0] = GetX(); |
| 690 | fVtxGuess[1] = GetY(); |
| 691 | fVtxGuess[2] = GetZ(); |
| f826d409 |
692 | fIsLinearized = 1; |
| 693 | maxIter = 3; |
| 694 | } |
| 695 | |
| 696 | for( Int_t iter=0; iter<maxIter; iter++ ){ |
| f826d409 |
697 | fAtProductionVertex = 0; |
| 698 | fSFromDecay = 0; |
| 699 | fP[0] = fVtxGuess[0]; |
| 700 | fP[1] = fVtxGuess[1]; |
| 701 | fP[2] = fVtxGuess[2]; |
| 702 | fP[3] = 0; |
| 703 | fP[4] = 0; |
| 704 | fP[5] = 0; |
| 705 | fP[6] = 0; |
| 706 | fP[7] = 0; |
| 707 | |
| 708 | for(Int_t i=0;i<36;++i) fC[i]=0.; |
| 709 | |
| 710 | fC[0] = fC[2] = fC[5] = 100.; |
| 711 | fC[35] = 1.; |
| 712 | |
| 713 | fNDF = -3; |
| 714 | fChi2 = 0.; |
| 715 | fQ = 0; |
| 716 | |
| 4bbc290d |
717 | for( Int_t itr =0; itr<NDaughters; itr++ ){ |
| 718 | AddDaughter( *vDaughters[itr] ); |
| 719 | } |
| f826d409 |
720 | if( iter<maxIter-1){ |
| 721 | for( Int_t i=0; i<3; i++ ) fVtxGuess[i] = fP[i]; |
| 722 | } |
| 723 | } |
| 724 | fIsLinearized = wasLinearized; |
| 725 | |
| 726 | if( Mass>=0 ) SetMassConstraint( Mass ); |
| 727 | if( Parent ) SetProductionVertex( *Parent ); |
| 728 | } |
| 729 | |
| 730 | |
| 731 | void AliKFParticleBase::Convert( bool ToProduction ) |
| 732 | { |
| 733 | //* Tricky function - convert the particle error along its trajectory to |
| 734 | //* the value which corresponds to its production/decay vertex |
| 735 | //* It is done by combination of the error of decay length with the position errors |
| 736 | |
| 737 | Double_t fld[3]; |
| 738 | { |
| 739 | GetFieldValue( fP, fld ); |
| 740 | const Double_t kCLight = fQ*0.000299792458; |
| 741 | fld[0]*=kCLight; fld[1]*=kCLight; fld[2]*=kCLight; |
| 742 | } |
| 743 | |
| 744 | Double_t h[6]; |
| 745 | |
| 746 | h[0] = fP[3]; |
| 747 | h[1] = fP[4]; |
| 748 | h[2] = fP[5]; |
| 749 | if( ToProduction ){ h[0]=-h[0]; h[1]=-h[1]; h[2]=-h[2]; } |
| 750 | h[3] = h[1]*fld[2]-h[2]*fld[1]; |
| 751 | h[4] = h[2]*fld[0]-h[0]*fld[2]; |
| 752 | h[5] = h[0]*fld[1]-h[1]*fld[0]; |
| 753 | |
| 754 | Double_t c; |
| 755 | |
| 756 | c = fC[28]+h[0]*fC[35]; |
| 757 | fC[ 0]+= h[0]*(c+fC[28]); |
| 758 | fC[28] = c; |
| 759 | |
| 760 | fC[ 1]+= h[1]*fC[28] + h[0]*fC[29]; |
| 761 | c = fC[29]+h[1]*fC[35]; |
| 762 | fC[ 2]+= h[1]*(c+fC[29]); |
| 763 | fC[29] = c; |
| 764 | |
| 765 | fC[ 3]+= h[2]*fC[28] + h[0]*fC[30]; |
| 766 | fC[ 4]+= h[2]*fC[29] + h[1]*fC[30]; |
| 767 | c = fC[30]+h[2]*fC[35]; |
| 768 | fC[ 5]+= h[2]*(c+fC[30]); |
| 769 | fC[30] = c; |
| 770 | |
| 771 | fC[ 6]+= h[3]*fC[28] + h[0]*fC[31]; |
| 772 | fC[ 7]+= h[3]*fC[29] + h[1]*fC[31]; |
| 773 | fC[ 8]+= h[3]*fC[30] + h[2]*fC[31]; |
| 774 | c = fC[31]+h[3]*fC[35]; |
| 775 | fC[ 9]+= h[3]*(c+fC[31]); |
| 776 | fC[31] = c; |
| 777 | |
| 778 | fC[10]+= h[4]*fC[28] + h[0]*fC[32]; |
| 779 | fC[11]+= h[4]*fC[29] + h[1]*fC[32]; |
| 780 | fC[12]+= h[4]*fC[30] + h[2]*fC[32]; |
| 781 | fC[13]+= h[4]*fC[31] + h[3]*fC[32]; |
| 782 | c = fC[32]+h[4]*fC[35]; |
| 783 | fC[14]+= h[4]*(c+fC[32]); |
| 784 | fC[32] = c; |
| 785 | |
| 786 | fC[15]+= h[5]*fC[28] + h[0]*fC[33]; |
| 787 | fC[16]+= h[5]*fC[29] + h[1]*fC[33]; |
| 788 | fC[17]+= h[5]*fC[30] + h[2]*fC[33]; |
| 789 | fC[18]+= h[5]*fC[31] + h[3]*fC[33]; |
| 790 | fC[19]+= h[5]*fC[32] + h[4]*fC[33]; |
| 791 | c = fC[33]+h[5]*fC[35]; |
| 792 | fC[20]+= h[5]*(c+fC[33]); |
| 793 | fC[33] = c; |
| 794 | |
| 795 | fC[21]+= h[0]*fC[34]; |
| 796 | fC[22]+= h[1]*fC[34]; |
| 797 | fC[23]+= h[2]*fC[34]; |
| 798 | fC[24]+= h[3]*fC[34]; |
| 799 | fC[25]+= h[4]*fC[34]; |
| 800 | fC[26]+= h[5]*fC[34]; |
| 801 | } |
| 802 | |
| 803 | |
| 804 | void AliKFParticleBase::TransportToDecayVertex() |
| 805 | { |
| 806 | //* Transport the particle to its decay vertex |
| 807 | |
| 808 | if( fSFromDecay != 0 ) TransportToDS( -fSFromDecay ); |
| 809 | if( fAtProductionVertex ) Convert(0); |
| 810 | fAtProductionVertex = 0; |
| 811 | } |
| 812 | |
| 813 | void AliKFParticleBase::TransportToProductionVertex() |
| 814 | { |
| 815 | //* Transport the particle to its production vertex |
| 616ffc76 |
816 | |
| f826d409 |
817 | if( fSFromDecay != -fP[7] ) TransportToDS( -fSFromDecay-fP[7] ); |
| 818 | if( !fAtProductionVertex ) Convert( 1 ); |
| 819 | fAtProductionVertex = 1; |
| 820 | } |
| 821 | |
| 822 | |
| 823 | void AliKFParticleBase::TransportToDS( Double_t dS ) |
| 824 | { |
| 825 | //* Transport the particle on dS parameter (SignedPath/Momentum) |
| 616ffc76 |
826 | |
| f826d409 |
827 | Transport( dS, fP, fC ); |
| 828 | fSFromDecay+= dS; |
| 829 | } |
| 830 | |
| 831 | |
| 832 | Double_t AliKFParticleBase::GetDStoPointLine( const Double_t xyz[] ) const |
| 833 | { |
| 834 | //* Get dS to a certain space point without field |
| 835 | |
| 836 | Double_t p2 = fP[3]*fP[3] + fP[4]*fP[4] + fP[5]*fP[5]; |
| 837 | if( p2<1.e-4 ) p2 = 1; |
| 838 | return ( fP[3]*(xyz[0]-fP[0]) + fP[4]*(xyz[1]-fP[1]) + fP[5]*(xyz[2]-fP[2]) )/p2; |
| 839 | } |
| 840 | |
| 841 | |
| 842 | Double_t AliKFParticleBase::GetDStoPointBz( Double_t B, const Double_t xyz[] ) |
| 843 | const |
| 844 | { |
| 616ffc76 |
845 | |
| f826d409 |
846 | //* Get dS to a certain space point for Bz field |
| f826d409 |
847 | const Double_t kCLight = 0.000299792458; |
| 848 | Double_t bq = B*fQ*kCLight; |
| 849 | Double_t pt2 = fP[3]*fP[3] + fP[4]*fP[4]; |
| 850 | if( pt2<1.e-4 ) return 0; |
| 851 | Double_t dx = xyz[0] - fP[0]; |
| 852 | Double_t dy = xyz[1] - fP[1]; |
| 853 | Double_t a = dx*fP[3]+dy*fP[4]; |
| 616ffc76 |
854 | if( TMath::Abs(bq)<1.e-8 ) return a/pt2; |
| f826d409 |
855 | return TMath::ATan2( bq*a, pt2 + bq*(dy*fP[3] -dx*fP[4]) )/bq; |
| 856 | } |
| 857 | |
| 858 | |
| 859 | void AliKFParticleBase::GetDStoParticleBz( Double_t B, const AliKFParticleBase &p, |
| 616ffc76 |
860 | Double_t &DS, Double_t &DS1 ) |
| f826d409 |
861 | const |
| 862 | { |
| 863 | //* Get dS to another particle for Bz field |
| f826d409 |
864 | Double_t px = fP[3]; |
| 865 | Double_t py = fP[4]; |
| 866 | Double_t pz = fP[5]; |
| 867 | |
| 868 | Double_t px1 = p.fP[3]; |
| 869 | Double_t py1 = p.fP[4]; |
| 870 | Double_t pz1 = p.fP[5]; |
| 871 | |
| 872 | const Double_t kCLight = 0.000299792458; |
| 873 | |
| 874 | Double_t bq = B*fQ*kCLight; |
| 875 | Double_t bq1 = B*p.fQ*kCLight; |
| f826d409 |
876 | Double_t s=0, ds=0, s1=0, ds1=0; |
| 877 | |
| 878 | if( TMath::Abs(bq)>1.e-8 || TMath::Abs(bq1)>1.e-8 ){ |
| 4bbc290d |
879 | |
| f826d409 |
880 | Double_t dx = (p.fP[0] - fP[0]); |
| 881 | Double_t dy = (p.fP[1] - fP[1]); |
| 882 | Double_t d2 = (dx*dx+dy*dy); |
| 883 | |
| 884 | Double_t p2 = (px *px + py *py); |
| 885 | Double_t p21 = (px1*px1 + py1*py1); |
| 886 | |
| 887 | Double_t a = (px*py1 - py*px1); |
| 888 | Double_t b = (px*px1 + py*py1); |
| 889 | |
| 890 | Double_t ldx = bq*bq1*dx - bq1*py + bq*py1 ; |
| 891 | Double_t ldy = bq*bq1*dy + bq1*px - bq*px1 ; |
| 892 | Double_t l2 = ldx*ldx + ldy*ldy; |
| 893 | |
| 894 | Double_t cS = bq1*p2 + bq*bq1*(dy* px - dx* py) - bq*b; |
| 895 | Double_t cS1= bq*p21 - bq*bq1*(dy*px1 - dx*py1) - bq1*b; |
| 896 | |
| 897 | Double_t ca = bq*bq*bq1*d2 +2*( cS + bq*bq*(py1*dx-px1*dy)) ; |
| 898 | Double_t ca1 = bq*bq1*bq1*d2 +2*( cS1 - bq1*bq1*(py*dx-px*dy)) ; |
| 899 | |
| 900 | Double_t sa = 4*l2*p2 - ca*ca; |
| 901 | Double_t sa1 = 4*l2*p21 - ca1*ca1; |
| e7b09c95 |
902 | |
| f826d409 |
903 | if(sa<0) sa=0; |
| 904 | if(sa1<0)sa1=0; |
| 905 | |
| 906 | if( TMath::Abs(bq)>1.e-8){ |
| 907 | s = TMath::ATan2( bq*( bq1*(dx*px +dy*py) + a ) , cS )/bq; |
| 908 | ds = TMath::ATan2(TMath::Sqrt(sa),ca)/bq; |
| 909 | } else { |
| 910 | s = ( (dx*px + dy*py) + (py*px1-px*py1)/bq1)/p2; |
| 911 | ds = s*s - (d2-2*(px1*dy-py1*dx)/bq1)/p2; |
| 912 | if( ds<0 ) ds = 0; |
| 913 | ds = TMath::Sqrt(ds); |
| 914 | } |
| 915 | |
| 916 | if( TMath::Abs(bq1)>1.e-8){ |
| 917 | s1 = TMath::ATan2( -bq1*( bq*(dx*px1+dy*py1) + a), cS1 )/bq1; |
| 918 | ds1 = TMath::ATan2(TMath::Sqrt(sa1),ca1)/bq1; |
| 919 | } else { |
| 920 | s1 = (-(dx*px1 + dy*py1) + (py*px1-px*py1)/bq)/p21; |
| 921 | ds1 = s1*s1 - (d2+2*(px*dy-py*dx)/bq)/p21; |
| 922 | if( ds1<0 ) ds1 = 0; |
| 923 | ds1 = TMath::Sqrt(ds1); |
| 924 | } |
| 925 | } |
| 926 | |
| f826d409 |
927 | Double_t ss[2], ss1[2], g[2][5],g1[2][5]; |
| 928 | |
| 929 | ss[0] = s + ds; |
| 930 | ss[1] = s - ds; |
| 931 | ss1[0] = s1 + ds1; |
| 932 | ss1[1] = s1 - ds1; |
| 933 | for( Int_t i=0; i<2; i++){ |
| 934 | Double_t bs = bq*ss[i]; |
| 935 | Double_t c = TMath::Cos(bs), s = TMath::Sin(bs); |
| 936 | Double_t cB,sB; |
| 937 | if( TMath::Abs(bq)>1.e-8){ |
| 938 | cB= (1-c)/bq; |
| 939 | sB= s/bq; |
| 940 | }else{ |
| 941 | sB = (1. - bs*bs/6.)*ss[i]; |
| 942 | cB = .5*sB*bs; |
| 943 | } |
| 944 | g[i][0] = fP[0] + sB*px + cB*py; |
| 945 | g[i][1] = fP[1] - cB*px + sB*py; |
| 946 | g[i][2] = fP[2] + ss[i]*pz; |
| 947 | g[i][3] = + c*px + s*py; |
| 948 | g[i][4] = - s*px + c*py; |
| 949 | |
| 950 | bs = bq1*ss1[i]; |
| 951 | c = TMath::Cos(bs); s = TMath::Sin(bs); |
| 952 | if( TMath::Abs(bq1)>1.e-8){ |
| 953 | cB= (1-c)/bq1; |
| 954 | sB= s/bq1; |
| 955 | }else{ |
| 956 | sB = (1. - bs*bs/6.)*ss1[i]; |
| 957 | cB = .5*sB*bs; |
| 958 | } |
| 959 | |
| e7b09c95 |
960 | g1[i][0] = p.fP[0] + sB*px1 + cB*py1; |
| 961 | g1[i][1] = p.fP[1] - cB*px1 + sB*py1; |
| 962 | g1[i][2] = p.fP[2] + ss[i]*pz1; |
| 963 | g1[i][3] = + c*px1 + s*py1; |
| 964 | g1[i][4] = - s*px1 + c*py1; |
| f826d409 |
965 | } |
| 966 | |
| 967 | Int_t i=0, i1=0; |
| 968 | |
| 969 | Double_t dMin = 1.e10; |
| 970 | for( Int_t j=0; j<2; j++){ |
| 971 | for( Int_t j1=0; j1<2; j1++){ |
| 972 | Double_t xx = g[j][0]-g1[j1][0]; |
| 973 | Double_t yy = g[j][1]-g1[j1][1]; |
| 974 | Double_t zz = g[j][2]-g1[j1][2]; |
| 975 | Double_t d = xx*xx + yy*yy + zz*zz; |
| 976 | if( d<dMin ){ |
| 977 | dMin = d; |
| 978 | i = j; |
| 979 | i1 = j1; |
| 980 | } |
| 981 | } |
| 982 | } |
| 983 | |
| 984 | DS = ss[i]; |
| 985 | DS1 = ss1[i1]; |
| 91468b27 |
986 | if(0){ |
| 987 | Double_t x= g[i][0], y= g[i][1], z= g[i][2], ppx= g[i][3], ppy= g[i][4]; |
| 988 | Double_t x1=g1[i1][0], y1= g1[i1][1], z1= g1[i1][2], ppx1= g1[i1][3], ppy1= g1[i1][4]; |
| 989 | Double_t dx = x1-x; |
| 990 | Double_t dy = y1-y; |
| 991 | Double_t dz = z1-z; |
| 992 | Double_t a = ppx*ppx1 + ppy*ppy1 + pz*pz1; |
| 993 | Double_t b = dx*ppx1 + dy*ppy1 + dz*pz1; |
| 994 | Double_t c = dx*ppx + dy*ppy + dz*pz ; |
| 995 | Double_t pp2 = ppx*ppx + ppy*ppy + pz*pz; |
| 996 | Double_t pp21= ppx1*ppx1 + ppy1*ppy1 + pz1*pz1; |
| 997 | Double_t det = pp2*pp21 - a*a; |
| 998 | if( TMath::Abs(det)>1.e-8 ){ |
| 999 | DS+=(a*b-pp21*c)/det; |
| 1000 | DS1+=(a*c-pp2*b)/det; |
| 1001 | } |
| f826d409 |
1002 | } |
| 1003 | } |
| 1004 | |
| 1005 | |
| 1006 | |
| 1007 | void AliKFParticleBase::TransportCBM( Double_t dS, |
| 1008 | Double_t P[], Double_t C[] ) const |
| 1009 | { |
| 1010 | //* Transport the particle on dS, output to P[],C[], for CBM field |
| 1011 | |
| 1012 | if( fQ==0 ){ |
| 1013 | TransportLine( dS, P, C ); |
| 1014 | return; |
| 1015 | } |
| 1016 | |
| 1017 | const Double_t kCLight = 0.000299792458; |
| 1018 | |
| 1019 | Double_t c = fQ*kCLight; |
| 1020 | |
| 1021 | // construct coefficients |
| 1022 | |
| 1023 | Double_t |
| 1024 | px = fP[3], |
| 1025 | py = fP[4], |
| 1026 | pz = fP[5]; |
| 1027 | |
| 1028 | 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; |
| 1029 | |
| 1030 | { // get field integrals |
| 1031 | |
| 1032 | Double_t fld[3][3]; |
| 1033 | Double_t p0[3], p1[3], p2[3]; |
| 1034 | |
| 1035 | // line track approximation |
| 1036 | |
| 1037 | p0[0] = fP[0]; |
| 1038 | p0[1] = fP[1]; |
| 1039 | p0[2] = fP[2]; |
| 1040 | |
| 1041 | p2[0] = fP[0] + px*dS; |
| 1042 | p2[1] = fP[1] + py*dS; |
| 1043 | p2[2] = fP[2] + pz*dS; |
| 1044 | |
| 1045 | p1[0] = 0.5*(p0[0]+p2[0]); |
| 1046 | p1[1] = 0.5*(p0[1]+p2[1]); |
| 1047 | p1[2] = 0.5*(p0[2]+p2[2]); |
| 1048 | |
| 1049 | // first order track approximation |
| 1050 | { |
| 1051 | GetFieldValue( p0, fld[0] ); |
| 1052 | GetFieldValue( p1, fld[1] ); |
| 1053 | GetFieldValue( p2, fld[2] ); |
| 1054 | |
| 1055 | Double_t ssy1 = ( 7*fld[0][1] + 6*fld[1][1]-fld[2][1] )*c*dS*dS/96.; |
| 1056 | Double_t ssy2 = ( fld[0][1] + 2*fld[1][1] )*c*dS*dS/6.; |
| 1057 | |
| 1058 | p1[0] -= ssy1*pz; |
| 1059 | p1[2] += ssy1*px; |
| 1060 | p2[0] -= ssy2*pz; |
| 1061 | p2[2] += ssy2*px; |
| 1062 | } |
| 1063 | |
| 1064 | GetFieldValue( p0, fld[0] ); |
| 1065 | GetFieldValue( p1, fld[1] ); |
| 1066 | GetFieldValue( p2, fld[2] ); |
| 1067 | |
| 1068 | sx = c*( fld[0][0] + 4*fld[1][0] + fld[2][0] )*dS/6.; |
| 1069 | sy = c*( fld[0][1] + 4*fld[1][1] + fld[2][1] )*dS/6.; |
| 1070 | sz = c*( fld[0][2] + 4*fld[1][2] + fld[2][2] )*dS/6.; |
| 1071 | |
| 1072 | ssx = c*( fld[0][0] + 2*fld[1][0])*dS*dS/6.; |
| 1073 | ssy = c*( fld[0][1] + 2*fld[1][1])*dS*dS/6.; |
| 1074 | ssz = c*( fld[0][2] + 2*fld[1][2])*dS*dS/6.; |
| 1075 | |
| 1076 | Double_t c2[3][3] = { { 5, -4, -1},{ 44, 80, -4},{ 11, 44, 5} }; // /=360. |
| 1077 | Double_t cc2[3][3] = { { 38, 8, -4},{ 148, 208, -20},{ 3, 36, 3} }; // /=2520. |
| 1078 | for(Int_t n=0; n<3; n++) |
| 1079 | for(Int_t m=0; m<3; m++) |
| 1080 | { |
| 1081 | syz += c2[n][m]*fld[n][1]*fld[m][2]; |
| 1082 | ssyz += cc2[n][m]*fld[n][1]*fld[m][2]; |
| 1083 | } |
| 1084 | |
| 1085 | syz *= c*c*dS*dS/360.; |
| 1086 | ssyz *= c*c*dS*dS*dS/2520.; |
| 1087 | |
| 1088 | syy = c*( fld[0][1] + 4*fld[1][1] + fld[2][1] )*dS; |
| 1089 | syyy = syy*syy*syy / 1296; |
| 1090 | syy = syy*syy/72; |
| 1091 | |
| 1092 | ssyy = ( fld[0][1]*( 38*fld[0][1] + 156*fld[1][1] - fld[2][1] )+ |
| 1093 | fld[1][1]*( 208*fld[1][1] +16*fld[2][1] )+ |
| 1094 | fld[2][1]*( 3*fld[2][1] ) |
| 1095 | )*dS*dS*dS*c*c/2520.; |
| 1096 | ssyyy = |
| 1097 | ( |
| 1098 | fld[0][1]*( fld[0][1]*( 85*fld[0][1] + 526*fld[1][1] - 7*fld[2][1] )+ |
| 1099 | fld[1][1]*( 1376*fld[1][1] +84*fld[2][1] )+ |
| 1100 | fld[2][1]*( 19*fld[2][1] ) )+ |
| 1101 | fld[1][1]*( fld[1][1]*( 1376*fld[1][1] +256*fld[2][1] )+ |
| 1102 | fld[2][1]*( 62*fld[2][1] ) )+ |
| 1103 | fld[2][1]*fld[2][1] *( 3*fld[2][1] ) |
| 1104 | )*dS*dS*dS*dS*c*c*c/90720.; |
| 1105 | |
| 1106 | } |
| 1107 | |
| 1108 | Double_t mJ[8][8]; |
| 1109 | for( Int_t i=0; i<8; i++ ) for( Int_t j=0; j<8; j++) mJ[i][j]=0; |
| 1110 | |
| 1111 | 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; |
| 1112 | 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; |
| 1113 | 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; |
| 1114 | |
| 1115 | 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; |
| 1116 | 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; |
| 1117 | 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; |
| 1118 | mJ[6][6] = mJ[7][7] = 1; |
| 1119 | |
| 1120 | P[0] = fP[0] + mJ[0][3]*px + mJ[0][4]*py + mJ[0][5]*pz; |
| 1121 | P[1] = fP[1] + mJ[1][3]*px + mJ[1][4]*py + mJ[1][5]*pz; |
| 1122 | P[2] = fP[2] + mJ[2][3]*px + mJ[2][4]*py + mJ[2][5]*pz; |
| 1123 | P[3] = mJ[3][3]*px + mJ[3][4]*py + mJ[3][5]*pz; |
| 1124 | P[4] = mJ[4][3]*px + mJ[4][4]*py + mJ[4][5]*pz; |
| 1125 | P[5] = mJ[5][3]*px + mJ[5][4]*py + mJ[5][5]*pz; |
| 1126 | P[6] = fP[6]; |
| 1127 | P[7] = fP[7]; |
| 1128 | |
| 1129 | MultQSQt( mJ[0], fC, C); |
| 1130 | |
| 1131 | } |
| 1132 | |
| 1133 | |
| 1134 | void AliKFParticleBase::TransportBz( Double_t B, Double_t S, |
| 616ffc76 |
1135 | Double_t P[], Double_t C[] ) const |
| f826d409 |
1136 | { |
| 1137 | //* Transport the particle on dS, output to P[],C[], for Bz field |
| 616ffc76 |
1138 | |
| f826d409 |
1139 | const Double_t kCLight = 0.000299792458; |
| 1140 | B = B*fQ*kCLight; |
| 1141 | Double_t bs= B*S; |
| 1142 | Double_t s = TMath::Sin(bs), c = TMath::Cos(bs); |
| 1143 | Double_t sB, cB; |
| 616ffc76 |
1144 | if( TMath::Abs(bs)>1.e-10){ |
| f826d409 |
1145 | sB= s/B; |
| 1146 | cB= (1-c)/B; |
| 1147 | }else{ |
| 1148 | sB = (1. - bs*bs/6.)*S; |
| 1149 | cB = .5*sB*bs; |
| 1150 | } |
| 1151 | |
| 1152 | Double_t px = fP[3]; |
| 1153 | Double_t py = fP[4]; |
| 1154 | Double_t pz = fP[5]; |
| 1155 | |
| 1156 | P[0] = fP[0] + sB*px + cB*py; |
| 1157 | P[1] = fP[1] - cB*px + sB*py; |
| 1158 | P[2] = fP[2] + S*pz; |
| 1159 | P[3] = c*px + s*py; |
| 1160 | P[4] = -s*px + c*py; |
| 1161 | P[5] = fP[5]; |
| 1162 | P[6] = fP[6]; |
| 1163 | P[7] = fP[7]; |
| 1164 | |
| 1165 | Double_t mJ[8][8] = { {1,0,0, sB, cB, 0, 0, 0 }, |
| 616ffc76 |
1166 | {0,1,0, -cB, sB, 0, 0, 0 }, |
| 1167 | {0,0,1, 0, 0, S, 0, 0 }, |
| 1168 | {0,0,0, c, s, 0, 0, 0 }, |
| 1169 | {0,0,0, -s, c, 0, 0, 0 }, |
| 1170 | {0,0,0, 0, 0, 1, 0, 0 }, |
| 1171 | {0,0,0, 0, 0, 0, 1, 0 }, |
| 1172 | {0,0,0, 0, 0, 0, 0, 1 } }; |
| f826d409 |
1173 | Double_t mA[8][8]; |
| 1174 | for( Int_t k=0,i=0; i<8; i++) |
| 1175 | for( Int_t j=0; j<=i; j++, k++ ) mA[i][j] = mA[j][i] = fC[k]; |
| 1176 | |
| 1177 | Double_t mJC[8][8]; |
| 1178 | for( Int_t i=0; i<8; i++ ) |
| 1179 | for( Int_t j=0; j<8; j++ ){ |
| 1180 | mJC[i][j]=0; |
| 1181 | for( Int_t k=0; k<8; k++ ) mJC[i][j]+=mJ[i][k]*mA[k][j]; |
| 1182 | } |
| 1183 | |
| 1184 | for( Int_t k=0,i=0; i<8; i++) |
| 1185 | for( Int_t j=0; j<=i; j++, k++ ){ |
| 1186 | C[k] = 0; |
| 1187 | for( Int_t l=0; l<8; l++ ) C[k]+=mJC[i][l]*mJ[j][l]; |
| 1188 | } |
| 1189 | |
| 1190 | return; |
| 1191 | /* |
| 1192 | Double_t cBC13 = cB*fC[13]; |
| 1193 | Double_t C17 = fC[17]; |
| 1194 | Double_t C18 = fC[18]; |
| 1195 | fC[ 0]+= 2*(sB*fC[ 6] + cB*fC[10]) + (sB*fC[ 9] + 2*cBC13)*sB + cB*cB*fC[14]; |
| 1196 | |
| 1197 | Double_t mJC13= fC[ 7] - cB*fC[ 9] + sB*fC[13]; |
| 1198 | Double_t mJC14= fC[11] - cBC13 + sB*fC[14]; |
| 1199 | |
| 1200 | fC[ 1]+= -cB*fC[ 6] + sB*fC[10] +mJC13*sB +mJC14*cB; |
| 1201 | fC[ 2]+= -cB*fC[ 7] + sB*fC[11] -mJC13*cB +mJC14*sB; |
| 1202 | |
| 1203 | Double_t mJC23= fC[ 8] + S*fC[18]; |
| 1204 | Double_t mJC24= fC[12] + S*fC[19]; |
| 1205 | fC[ 3]+= S*fC[15] +mJC23*sB +mJC24*cB; |
| 1206 | fC[ 4]+= S*fC[16] -mJC23*cB +mJC24*sB; |
| 1207 | |
| 1208 | fC[15]+= C18*sB + fC[19]*cB; |
| 1209 | fC[16]+= -C18*cB + fC[19]*sB; |
| 1210 | fC[17]+= fC[20]*S; |
| 1211 | fC[18] = C18*c + fC[19]*s; |
| 1212 | fC[19] = -C18*s + fC[19]*c; |
| 1213 | |
| 1214 | fC[ 5]+= (C17 + C17 + fC[17])*S; |
| 1215 | |
| 1216 | Double_t mJC33= c*fC[ 9] + s*fC[13]; Double_t mJC34= c*fC[13] + s*fC[14]; |
| 1217 | Double_t mJC43=-s*fC[ 9] + c*fC[13]; Double_t mJC44=-s*fC[13] + c*fC[14]; |
| 1218 | Double_t C6= fC[6], C7= fC[7], C8= fC[8]; |
| 1219 | |
| 1220 | fC[ 6]= c*C6 + s*fC[10] +mJC33*sB +mJC34*cB; |
| 1221 | fC[ 7]= c*C7 + s*fC[11] -mJC33*cB +mJC34*sB; |
| 1222 | fC[ 8]= c*C8 + s*fC[12] +fC[18]*S; |
| 1223 | fC[ 9]= mJC33*c +mJC34*s; |
| 1224 | |
| 1225 | fC[10]= -s*C6 + c*fC[10] +mJC43*sB +mJC44*cB; |
| 1226 | fC[11]= -s*C7 + c*fC[11] -mJC43*cB +mJC44*sB; |
| 1227 | fC[12]= -s*C8 + c*fC[12] +fC[19]*S; |
| 1228 | fC[13]= mJC43*c +mJC44*s; |
| 1229 | fC[14]=-mJC43*s +mJC44*c; |
| 1230 | */ |
| 1231 | } |
| 1232 | |
| 1233 | |
| 1234 | Double_t AliKFParticleBase::GetDistanceFromVertex( const AliKFParticleBase &Vtx ) const |
| 1235 | { |
| 1236 | //* Calculate distance from vertex [cm] |
| 1237 | |
| 1238 | return GetDistanceFromVertex( Vtx.fP ); |
| 1239 | } |
| 1240 | |
| 1241 | Double_t AliKFParticleBase::GetDistanceFromVertex( const Double_t vtx[] ) const |
| 1242 | { |
| 1243 | //* Calculate distance from vertex [cm] |
| 1244 | |
| 1245 | Double_t mP[8], mC[36]; |
| 1246 | Transport( GetDStoPoint(vtx), mP, mC ); |
| 1247 | Double_t d[3]={ vtx[0]-mP[0], vtx[1]-mP[1], vtx[2]-mP[2]}; |
| 1248 | return TMath::Sqrt( d[0]*d[0]+d[1]*d[1]+d[2]*d[2] ); |
| 1249 | } |
| 1250 | |
| 616ffc76 |
1251 | Double_t AliKFParticleBase::GetDistanceFromParticle( const AliKFParticleBase &p ) |
| f826d409 |
1252 | const |
| 1253 | { |
| 616ffc76 |
1254 | //* Calculate distance to other particle [cm] |
| f826d409 |
1255 | |
| 1256 | Double_t dS, dS1; |
| 616ffc76 |
1257 | GetDStoParticle( p, dS, dS1 ); |
| f826d409 |
1258 | Double_t mP[8], mC[36], mP1[8], mC1[36]; |
| 616ffc76 |
1259 | Transport( dS, mP, mC ); |
| 1260 | p.Transport( dS1, mP1, mC1 ); |
| f826d409 |
1261 | Double_t dx = mP[0]-mP1[0]; |
| 1262 | Double_t dy = mP[1]-mP1[1]; |
| 1263 | Double_t dz = mP[2]-mP1[2]; |
| 1264 | return TMath::Sqrt(dx*dx+dy*dy+dz*dz); |
| 1265 | } |
| 1266 | |
| 1267 | Double_t AliKFParticleBase::GetDeviationFromVertex( const AliKFParticleBase &Vtx ) const |
| 1268 | { |
| 1269 | //* Calculate sqrt(Chi2/ndf) deviation from vertex |
| 1270 | |
| 1271 | return GetDeviationFromVertex( Vtx.fP, Vtx.fC ); |
| 1272 | } |
| 1273 | |
| 1274 | |
| 1275 | Double_t AliKFParticleBase::GetDeviationFromVertex( const Double_t v[], const Double_t Cv[] ) const |
| 1276 | { |
| 1277 | //* Calculate sqrt(Chi2/ndf) deviation from vertex |
| 1278 | //* v = [xyz], Cv=[Cxx,Cxy,Cyy,Cxz,Cyz,Czz]-covariance matrix |
| 1279 | |
| 1280 | Double_t mP[8]; |
| 1281 | Double_t mC[36]; |
| 1282 | |
| 1283 | Transport( GetDStoPoint(v), mP, mC ); |
| 1284 | |
| 1285 | Double_t d[3]={ v[0]-mP[0], v[1]-mP[1], v[2]-mP[2]}; |
| 1286 | |
| 1287 | Double_t sigmaS = .1+10.*TMath::Sqrt( (d[0]*d[0]+d[1]*d[1]+d[2]*d[2])/ |
| 1288 | (mP[3]*mP[3]+mP[4]*mP[4]+mP[5]*mP[5]) ); |
| 1289 | |
| 1290 | |
| 1291 | Double_t h[3] = { mP[3]*sigmaS, mP[4]*sigmaS, mP[5]*sigmaS }; |
| 1292 | |
| 1293 | Double_t mSi[6] = |
| 1294 | { mC[0] +h[0]*h[0], |
| 1295 | mC[1] +h[1]*h[0], mC[2] +h[1]*h[1], |
| 1296 | mC[3] +h[2]*h[0], mC[4] +h[2]*h[1], mC[5] +h[2]*h[2] }; |
| 1297 | |
| 1298 | if( Cv ){ |
| 1299 | mSi[0]+=Cv[0]; |
| 1300 | mSi[1]+=Cv[1]; |
| 1301 | mSi[2]+=Cv[2]; |
| 1302 | mSi[3]+=Cv[3]; |
| 1303 | mSi[4]+=Cv[4]; |
| 1304 | mSi[5]+=Cv[5]; |
| 1305 | } |
| 1306 | |
| 1307 | Double_t mS[6]; |
| 1308 | |
| 1309 | mS[0] = mSi[2]*mSi[5] - mSi[4]*mSi[4]; |
| 1310 | mS[1] = mSi[3]*mSi[4] - mSi[1]*mSi[5]; |
| 1311 | mS[2] = mSi[0]*mSi[5] - mSi[3]*mSi[3]; |
| 1312 | mS[3] = mSi[1]*mSi[4] - mSi[2]*mSi[3]; |
| 1313 | mS[4] = mSi[1]*mSi[3] - mSi[0]*mSi[4]; |
| 1314 | mS[5] = mSi[0]*mSi[2] - mSi[1]*mSi[1]; |
| 1315 | |
| 1316 | Double_t s = ( mSi[0]*mS[0] + mSi[1]*mS[1] + mSi[3]*mS[3] ); |
| 1317 | s = ( s > 1.E-20 ) ?1./s :0; |
| 1318 | |
| 1319 | return TMath::Sqrt( TMath::Abs(s*( ( mS[0]*d[0] + mS[1]*d[1] + mS[3]*d[2])*d[0] |
| 1320 | +(mS[1]*d[0] + mS[2]*d[1] + mS[4]*d[2])*d[1] |
| 1321 | +(mS[3]*d[0] + mS[4]*d[1] + mS[5]*d[2])*d[2] ))/2); |
| 1322 | } |
| 1323 | |
| 1324 | |
| 616ffc76 |
1325 | Double_t AliKFParticleBase::GetDeviationFromParticle( const AliKFParticleBase &p ) |
| f826d409 |
1326 | const |
| 1327 | { |
| 616ffc76 |
1328 | //* Calculate sqrt(Chi2/ndf) deviation from other particle |
| f826d409 |
1329 | |
| 1330 | Double_t dS, dS1; |
| 616ffc76 |
1331 | GetDStoParticle( p, dS, dS1 ); |
| f826d409 |
1332 | Double_t mP1[8], mC1[36]; |
| 616ffc76 |
1333 | p.Transport( dS1, mP1, mC1 ); |
| f826d409 |
1334 | |
| 1335 | Double_t d[3]={ fP[0]-mP1[0], fP[1]-mP1[1], fP[2]-mP1[2]}; |
| 1336 | |
| 1337 | Double_t sigmaS = .1+10.*TMath::Sqrt( (d[0]*d[0]+d[1]*d[1]+d[2]*d[2])/ |
| 616ffc76 |
1338 | (mP1[3]*mP1[3]+mP1[4]*mP1[4]+mP1[5]*mP1[5]) ); |
| f826d409 |
1339 | |
| 1340 | Double_t h[3] = { mP1[3]*sigmaS, mP1[4]*sigmaS, mP1[5]*sigmaS }; |
| 1341 | |
| 1342 | mC1[0] +=h[0]*h[0]; |
| 1343 | mC1[1] +=h[1]*h[0]; |
| 1344 | mC1[2] +=h[1]*h[1]; |
| 1345 | mC1[3] +=h[2]*h[0]; |
| 1346 | mC1[4] +=h[2]*h[1]; |
| 1347 | mC1[5] +=h[2]*h[2]; |
| 1348 | |
| 1349 | return GetDeviationFromVertex( mP1, mC1 )*TMath::Sqrt(2./1.); |
| 1350 | } |
| 1351 | |
| 1352 | |
| 1353 | |
| 1354 | void AliKFParticleBase::SubtractFromVertex( Double_t v[], Double_t Cv[], |
| 1355 | Double_t &vChi2, Int_t vNDF ) const |
| 1356 | { |
| 1357 | //* Subtract the particle from the vertex |
| 1358 | |
| 1359 | Double_t fld[3]; |
| 1360 | { |
| 1361 | GetFieldValue( v, fld ); |
| 1362 | const Double_t kCLight = 0.000299792458; |
| 1363 | fld[0]*=kCLight; fld[1]*=kCLight; fld[2]*=kCLight; |
| 1364 | } |
| 1365 | |
| 1366 | Double_t m[8]; |
| 1367 | Double_t mCm[36]; |
| 1368 | |
| 1369 | Transport( GetDStoPoint(v), m, mCm ); |
| 1370 | |
| 1371 | Double_t d[3] = { v[0]-m[0], v[1]-m[1], v[2]-m[2] }; |
| 1372 | Double_t sigmaS = .1+10.*TMath::Sqrt( (d[0]*d[0]+d[1]*d[1]+d[2]*d[2])/ |
| 1373 | (m[3]*m[3]+m[4]*m[4]+m[5]*m[5]) ); |
| 1374 | |
| 1375 | Double_t h[6]; |
| 1376 | |
| 1377 | h[0] = m[3]*sigmaS; |
| 1378 | h[1] = m[4]*sigmaS; |
| 1379 | h[2] = m[5]*sigmaS; |
| 1380 | h[3] = ( h[1]*fld[2]-h[2]*fld[1] )*GetQ(); |
| 1381 | h[4] = ( h[2]*fld[0]-h[0]*fld[2] )*GetQ(); |
| 1382 | h[5] = ( h[0]*fld[1]-h[1]*fld[0] )*GetQ(); |
| 1383 | |
| 1384 | //* Fit of daughter momentum (Px,Py,Pz) to fVtxGuess vertex |
| 1385 | { |
| 1386 | Double_t zeta[3] = { v[0]-m[0], v[1]-m[1], v[2]-m[2] }; |
| 1387 | |
| 1388 | Double_t mVv[6] = |
| 1389 | { mCm[ 0] + h[0]*h[0], |
| 1390 | mCm[ 1] + h[1]*h[0], mCm[ 2] + h[1]*h[1], |
| 1391 | mCm[ 3] + h[2]*h[0], mCm[ 4] + h[2]*h[1], mCm[ 5] + h[2]*h[2] }; |
| 1392 | |
| 1393 | Double_t mVvp[9]= |
| 1394 | { mCm[ 6] + h[0]*h[3], mCm[ 7] + h[1]*h[3], mCm[ 8] + h[2]*h[3], |
| 1395 | mCm[10] + h[0]*h[4], mCm[11] + h[1]*h[4], mCm[12] + h[2]*h[4], |
| 1396 | mCm[15] + h[0]*h[5], mCm[16] + h[1]*h[5], mCm[17] + h[2]*h[5] }; |
| 1397 | |
| 1398 | Double_t mS[6] = |
| 1399 | { mVv[2]*mVv[5] - mVv[4]*mVv[4], |
| 1400 | mVv[3]*mVv[4] - mVv[1]*mVv[5], mVv[0]*mVv[5] - mVv[3]*mVv[3], |
| 1401 | mVv[1]*mVv[4] - mVv[2]*mVv[3], mVv[1]*mVv[3] - mVv[0]*mVv[4], |
| 1402 | mVv[0]*mVv[2] - mVv[1]*mVv[1] }; |
| 1403 | |
| 1404 | Double_t s = ( mVv[0]*mS[0] + mVv[1]*mS[1] + mVv[3]*mS[3] ); |
| 1405 | s = ( s > 1.E-20 ) ?1./s :0; |
| 1406 | |
| 1407 | mS[0]*=s; mS[1]*=s; mS[2]*=s; mS[3]*=s; mS[4]*=s; mS[5]*=s; |
| 1408 | |
| 1409 | Double_t mSz[3] = { (mS[0]*zeta[0]+mS[1]*zeta[1]+mS[3]*zeta[2]), |
| 1410 | (mS[1]*zeta[0]+mS[2]*zeta[1]+mS[4]*zeta[2]), |
| 1411 | (mS[3]*zeta[0]+mS[4]*zeta[1]+mS[5]*zeta[2]) }; |
| 1412 | |
| 1413 | Double_t px = m[3] + mVvp[0]*mSz[0] + mVvp[1]*mSz[1] + mVvp[2]*mSz[2]; |
| 1414 | Double_t py = m[4] + mVvp[3]*mSz[0] + mVvp[4]*mSz[1] + mVvp[5]*mSz[2]; |
| 1415 | Double_t pz = m[5] + mVvp[6]*mSz[0] + mVvp[7]*mSz[1] + mVvp[8]*mSz[2]; |
| 1416 | |
| 1417 | h[0] = px*sigmaS; |
| 1418 | h[1] = py*sigmaS; |
| 1419 | h[2] = pz*sigmaS; |
| 1420 | h[3] = ( h[1]*fld[2]-h[2]*fld[1] )*GetQ(); |
| 1421 | h[4] = ( h[2]*fld[0]-h[0]*fld[2] )*GetQ(); |
| 1422 | h[5] = ( h[0]*fld[1]-h[1]*fld[0] )*GetQ(); |
| 1423 | } |
| 1424 | |
| 1425 | Double_t mV[6]; |
| 1426 | |
| 1427 | mV[ 0] = mCm[ 0] + h[0]*h[0]; |
| 1428 | mV[ 1] = mCm[ 1] + h[1]*h[0]; |
| 1429 | mV[ 2] = mCm[ 2] + h[1]*h[1]; |
| 1430 | mV[ 3] = mCm[ 3] + h[2]*h[0]; |
| 1431 | mV[ 4] = mCm[ 4] + h[2]*h[1]; |
| 1432 | mV[ 5] = mCm[ 5] + h[2]*h[2]; |
| 1433 | |
| 1434 | //* |
| 1435 | |
| 1436 | Double_t mS[6]; |
| 1437 | { |
| 1438 | Double_t mSi[6] = { mV[0]-Cv[0], |
| 1439 | mV[1]-Cv[1], mV[2]-Cv[2], |
| 1440 | mV[3]-Cv[3], mV[4]-Cv[4], mV[5]-Cv[5] }; |
| 1441 | |
| 1442 | mS[0] = mSi[2]*mSi[5] - mSi[4]*mSi[4]; |
| 1443 | mS[1] = mSi[3]*mSi[4] - mSi[1]*mSi[5]; |
| 1444 | mS[2] = mSi[0]*mSi[5] - mSi[3]*mSi[3]; |
| 1445 | mS[3] = mSi[1]*mSi[4] - mSi[2]*mSi[3]; |
| 1446 | mS[4] = mSi[1]*mSi[3] - mSi[0]*mSi[4]; |
| 1447 | mS[5] = mSi[0]*mSi[2] - mSi[1]*mSi[1]; |
| 1448 | |
| 1449 | Double_t s = ( mSi[0]*mS[0] + mSi[1]*mS[1] + mSi[3]*mS[3] ); |
| 1450 | s = ( s > 1.E-20 ) ?1./s :0; |
| 1451 | mS[0]*=s; |
| 1452 | mS[1]*=s; |
| 1453 | mS[2]*=s; |
| 1454 | mS[3]*=s; |
| 1455 | mS[4]*=s; |
| 1456 | mS[5]*=s; |
| 1457 | } |
| 1458 | |
| 1459 | //* Residual (measured - estimated) |
| 1460 | |
| 1461 | Double_t zeta[3] = { m[0]-v[0], m[1]-v[1], m[2]-v[2] }; |
| 1462 | |
| 1463 | //* mCHt = mCH' - D' |
| 1464 | |
| 1465 | Double_t mCHt0[3], mCHt1[3], mCHt2[3]; |
| 1466 | |
| 1467 | mCHt0[0]=Cv[ 0] ; mCHt1[0]=Cv[ 1] ; mCHt2[0]=Cv[ 3] ; |
| 1468 | mCHt0[1]=Cv[ 1] ; mCHt1[1]=Cv[ 2] ; mCHt2[1]=Cv[ 4] ; |
| 1469 | mCHt0[2]=Cv[ 3] ; mCHt1[2]=Cv[ 4] ; mCHt2[2]=Cv[ 5] ; |
| 1470 | |
| 1471 | //* Kalman gain K = mCH'*S |
| 1472 | |
| 1473 | Double_t k0[3], k1[3], k2[3]; |
| 1474 | |
| 1475 | for(Int_t i=0;i<3;++i){ |
| 1476 | k0[i] = mCHt0[i]*mS[0] + mCHt1[i]*mS[1] + mCHt2[i]*mS[3]; |
| 1477 | k1[i] = mCHt0[i]*mS[1] + mCHt1[i]*mS[2] + mCHt2[i]*mS[4]; |
| 1478 | k2[i] = mCHt0[i]*mS[3] + mCHt1[i]*mS[4] + mCHt2[i]*mS[5]; |
| 1479 | } |
| 1480 | |
| 1481 | //* New estimation of the vertex position r += K*zeta |
| 1482 | |
| 1483 | for(Int_t i=0;i<3;++i) |
| 1484 | v[i] -= k0[i]*zeta[0] + k1[i]*zeta[1] + k2[i]*zeta[2]; |
| 1485 | |
| 1486 | //* New covariance matrix C -= K*(mCH')' |
| 1487 | |
| 1488 | for(Int_t i=0, k=0;i<3;++i){ |
| 1489 | for(Int_t j=0;j<=i;++j,++k) |
| 1490 | Cv[k] += k0[i]*mCHt0[j] + k1[i]*mCHt1[j] + k2[i]*mCHt2[j]; |
| 1491 | } |
| 1492 | |
| 1493 | //* Calculate Chi^2 |
| 1494 | |
| 1495 | vNDF -= 2; |
| 1496 | vChi2 -= (mS[0]*zeta[0] + mS[1]*zeta[1] + mS[3]*zeta[2])*zeta[0] |
| 1497 | + (mS[1]*zeta[0] + mS[2]*zeta[1] + mS[4]*zeta[2])*zeta[1] |
| 1498 | + (mS[3]*zeta[0] + mS[4]*zeta[1] + mS[5]*zeta[2])*zeta[2]; |
| 1499 | } |
| 1500 | |
| 1501 | |
| 1502 | |
| 1503 | void AliKFParticleBase::TransportLine( Double_t dS, |
| 1504 | Double_t P[], Double_t C[] ) const |
| 1505 | { |
| 1506 | //* Transport the particle as a straight line |
| 1507 | |
| 1508 | P[0] = fP[0] + dS*fP[3]; |
| 1509 | P[1] = fP[1] + dS*fP[4]; |
| 1510 | P[2] = fP[2] + dS*fP[5]; |
| 1511 | P[3] = fP[3]; |
| 1512 | P[4] = fP[4]; |
| 1513 | P[5] = fP[5]; |
| 1514 | P[6] = fP[6]; |
| 1515 | P[7] = fP[7]; |
| 1516 | |
| 1517 | Double_t c6 = fC[ 6] + dS*fC[ 9]; |
| 1518 | Double_t c11 = fC[11] + dS*fC[14]; |
| 1519 | Double_t c17 = fC[17] + dS*fC[20]; |
| 1520 | Double_t sc13 = dS*fC[13]; |
| 1521 | Double_t sc18 = dS*fC[18]; |
| 1522 | Double_t sc19 = dS*fC[19]; |
| 1523 | |
| 1524 | C[ 0] = fC[ 0] + dS*( fC[ 6] + c6 ); |
| 1525 | C[ 2] = fC[ 2] + dS*( fC[11] + c11 ); |
| 1526 | C[ 5] = fC[ 5] + dS*( fC[17] + c17 ); |
| 1527 | |
| 1528 | C[ 7] = fC[ 7] + sc13; |
| 1529 | C[ 8] = fC[ 8] + sc18; |
| 1530 | C[ 9] = fC[ 9]; |
| 1531 | |
| 1532 | C[12] = fC[12] + sc19; |
| 1533 | |
| 1534 | C[ 1] = fC[ 1] + dS*( fC[10] + C[ 7] ); |
| 1535 | C[ 3] = fC[ 3] + dS*( fC[15] + C[ 8] ); |
| 1536 | C[ 4] = fC[ 4] + dS*( fC[16] + C[12] ); |
| 1537 | C[ 6] = c6; |
| 1538 | |
| 1539 | C[10] = fC[10] + sc13; |
| 1540 | C[11] = c11; |
| 1541 | |
| 1542 | C[13] = fC[13]; |
| 1543 | C[14] = fC[14]; |
| 1544 | C[15] = fC[15] + sc18; |
| 1545 | C[16] = fC[16] + sc19; |
| 1546 | C[17] = c17; |
| 1547 | |
| 1548 | C[18] = fC[18]; |
| 1549 | C[19] = fC[19]; |
| 1550 | C[20] = fC[20]; |
| 1551 | C[21] = fC[21] + dS*fC[24]; |
| 1552 | C[22] = fC[22] + dS*fC[25]; |
| 1553 | C[23] = fC[23] + dS*fC[26]; |
| 1554 | |
| 1555 | C[24] = fC[24]; |
| 1556 | C[25] = fC[25]; |
| 1557 | C[26] = fC[26]; |
| 1558 | C[27] = fC[27]; |
| 1559 | C[28] = fC[28] + dS*fC[31]; |
| 1560 | C[29] = fC[29] + dS*fC[32]; |
| 1561 | C[30] = fC[30] + dS*fC[33]; |
| 1562 | |
| 1563 | C[31] = fC[31]; |
| 1564 | C[32] = fC[32]; |
| 1565 | C[33] = fC[33]; |
| 1566 | C[34] = fC[34]; |
| 1567 | C[35] = fC[35]; |
| 1568 | } |
| 1569 | |
| 1570 | |
| 1571 | void AliKFParticleBase::MultQSQt( const Double_t Q[], const Double_t S[], Double_t SOut[] ) |
| 1572 | { |
| 1573 | //* Matrix multiplication Q*S*Q^T, Q - square matrix, S - symmetric |
| 1574 | |
| 1575 | const Int_t kN= 8; |
| 1576 | Double_t mA[kN*kN]; |
| 1577 | |
| 1578 | for( Int_t i=0, ij=0; i<kN; i++ ){ |
| 1579 | for( Int_t j=0; j<kN; j++, ++ij ){ |
| 1580 | mA[ij] = 0 ; |
| 1581 | 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]; |
| 1582 | } |
| 1583 | } |
| 1584 | |
| 1585 | for( Int_t i=0; i<kN; i++ ){ |
| 1586 | for( Int_t j=0; j<=i; j++ ){ |
| 1587 | Int_t ij = ( j<=i ) ? i*(i+1)/2+j :j*(j+1)/2+i; |
| 1588 | SOut[ij] = 0 ; |
| 1589 | for( Int_t k=0; k<kN; k++ ) SOut[ij] += Q[ i*kN+k ] * mA[ k*kN+j ]; |
| 1590 | } |
| 1591 | } |
| 1592 | } |
| 1593 | |
| 1594 | |
| 1595 | // 72-charachters line to define the printer border |
| 1596 | //3456789012345678901234567890123456789012345678901234567890123456789012 |
git://git.uio.no / u / mrichter / AliRoot.git / blame