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1 | /************************************************************************** |
| 2 | * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. * |
| 3 | * * |
| 4 | * Author: The ALICE Off-line Project. * |
| 5 | * Contributors are mentioned in the code where appropriate. * |
| 6 | * * |
| 7 | * Permission to use, copy, modify and distribute this software and its * |
| 8 | * documentation strictly for non-commercial purposes is hereby granted * |
| 9 | * without fee, provided that the above copyright notice appears in all * |
| 10 | * copies and that both the copyright notice and this permission notice * |
| 11 | * appear in the supporting documentation. The authors make no claims * |
| 12 | * about the suitability of this software for any purpose. It is * |
| 13 | * provided "as is" without express or implied warranty. * |
| 14 | **************************************************************************/ |
| 15 | |
| 16 | //------------------------------------------------------------------------- |
| 17 | // Implementation of the ITS track class |
| 18 | // |
| 19 | // Origin: Iouri Belikov, CERN, Jouri.Belikov@cern.ch |
| a9a2d814 |
20 | // dEdx analysis by: Boris Batyunya, JINR, Boris.Batiounia@cern.ch |
| 006b5f7f |
21 | //------------------------------------------------------------------------- |
| 22 | |
| 23 | #include <TMatrixD.h> |
| 24 | |
| 25 | #include <TMath.h> |
| 4ae5bbc4 |
26 | #include <Riostream.h> |
| 006b5f7f |
27 | |
| 28 | #include "AliCluster.h" |
| 517b130f |
29 | #include "AliTPCtrack.h" |
| 006b5f7f |
30 | #include "AliITStrackV2.h" |
| 31 | |
| 32 | ClassImp(AliITStrackV2) |
| 33 | |
| 7f6ddf58 |
34 | const Int_t kWARN=5; |
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35 | |
| 36 | //____________________________________________________________________________ |
| 37 | AliITStrackV2::AliITStrackV2(const AliTPCtrack& t) throw (const Char_t *) { |
| 38 | //------------------------------------------------------------------ |
| 9b280d80 |
39 | //Conversion TPC track -> ITS track |
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40 | //------------------------------------------------------------------ |
| 41 | SetLabel(t.GetLabel()); |
| 42 | SetChi2(0.); |
| 43 | SetNumberOfClusters(0); |
| 14825d5a |
44 | //SetConvConst(t.GetConvConst()); |
| 45 | |
| 7f6ddf58 |
46 | fdEdx = t.GetdEdx(); |
| 47 | SetMass(t.GetMass()); |
| 48 | |
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49 | fAlpha = t.GetAlpha(); |
| 50 | if (fAlpha < -TMath::Pi()) fAlpha += 2*TMath::Pi(); |
| 51 | else if (fAlpha >= TMath::Pi()) fAlpha -= 2*TMath::Pi(); |
| 52 | |
| 9b280d80 |
53 | //Conversion of the track parameters |
| 006b5f7f |
54 | Double_t x,p[5]; t.GetExternalParameters(x,p); |
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55 | fX=x; x=GetConvConst(); |
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56 | fP0=p[0]; |
| 57 | fP1=p[1]; |
| 58 | fP2=p[2]; |
| 59 | fP3=p[3]; |
| 60 | fP4=p[4]/x; |
| 61 | |
| 9b280d80 |
62 | //Conversion of the covariance matrix |
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63 | Double_t c[15]; t.GetExternalCovariance(c); |
| 64 | |
| 65 | fC00=c[0 ]; |
| 66 | fC10=c[1 ]; fC11=c[2 ]; |
| 67 | fC20=c[3 ]; fC21=c[4 ]; fC22=c[5 ]; |
| 68 | fC30=c[6 ]; fC31=c[7 ]; fC32=c[8 ]; fC33=c[9 ]; |
| 69 | fC40=c[10]/x; fC41=c[11]/x; fC42=c[12]/x; fC43=c[13]/x; fC44=c[14]/x/x; |
| 70 | |
| 71 | if (!Invariant()) throw "AliITStrackV2: conversion failed !\n"; |
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72 | |
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73 | } |
| 74 | |
| 75 | //____________________________________________________________________________ |
| 76 | AliITStrackV2::AliITStrackV2(const AliITStrackV2& t) : AliKalmanTrack(t) { |
| 77 | //------------------------------------------------------------------ |
| 78 | //Copy constructor |
| 79 | //------------------------------------------------------------------ |
| 80 | fX=t.fX; |
| 81 | fAlpha=t.fAlpha; |
| 82 | fdEdx=t.fdEdx; |
| 83 | |
| 84 | fP0=t.fP0; fP1=t.fP1; fP2=t.fP2; fP3=t.fP3; fP4=t.fP4; |
| 85 | |
| 86 | fC00=t.fC00; |
| 87 | fC10=t.fC10; fC11=t.fC11; |
| 88 | fC20=t.fC20; fC21=t.fC21; fC22=t.fC22; |
| 89 | fC30=t.fC30; fC31=t.fC31; fC32=t.fC32; fC33=t.fC33; |
| 90 | fC40=t.fC40; fC41=t.fC41; fC42=t.fC42; fC43=t.fC43; fC44=t.fC44; |
| 91 | |
| 92 | Int_t n=GetNumberOfClusters(); |
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93 | for (Int_t i=0; i<n; i++) { |
| a9a2d814 |
94 | fIndex[i]=t.fIndex[i]; |
| 95 | if (i<4) fdEdxSample[i]=t.fdEdxSample[i]; |
| 23efe5f1 |
96 | } |
| 006b5f7f |
97 | } |
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98 | |
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99 | //_____________________________________________________________________________ |
| 100 | Int_t AliITStrackV2::Compare(const TObject *o) const { |
| 101 | //----------------------------------------------------------------- |
| 102 | // This function compares tracks according to the their curvature |
| 103 | //----------------------------------------------------------------- |
| 7f6ddf58 |
104 | AliITStrackV2 *t=(AliITStrackV2*)o; |
| a9a2d814 |
105 | //Double_t co=TMath::Abs(t->Get1Pt()); |
| 106 | //Double_t c =TMath::Abs(Get1Pt()); |
| 107 | Double_t co=t->GetSigmaY2()*t->GetSigmaZ2(); |
| 108 | Double_t c =GetSigmaY2()*GetSigmaZ2(); |
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109 | if (c>co) return 1; |
| 110 | else if (c<co) return -1; |
| 111 | return 0; |
| 112 | } |
| 113 | |
| 114 | //_____________________________________________________________________________ |
| 115 | void AliITStrackV2::GetExternalCovariance(Double_t cc[15]) const { |
| 116 | //------------------------------------------------------------------------- |
| 117 | // This function returns an external representation of the covriance matrix. |
| 118 | // (See comments in AliTPCtrack.h about external track representation) |
| 119 | //------------------------------------------------------------------------- |
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120 | Double_t a=GetConvConst(); |
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121 | |
| 122 | cc[0 ]=fC00; |
| 123 | cc[1 ]=fC10; cc[2 ]=fC11; |
| 124 | cc[3 ]=fC20; cc[4 ]=fC21; cc[5 ]=fC22; |
| 125 | cc[6 ]=fC30; cc[7 ]=fC31; cc[8 ]=fC32; cc[9 ]=fC33; |
| 126 | cc[10]=fC40*a; cc[11]=fC41*a; cc[12]=fC42*a; cc[13]=fC43*a; cc[14]=fC44*a*a; |
| 127 | } |
| 128 | |
| 129 | //____________________________________________________________________________ |
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130 | Int_t AliITStrackV2::PropagateToVertex(Double_t d,Double_t x0) { |
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131 | //------------------------------------------------------------------ |
| 132 | //This function propagates a track to the minimal distance from the origin |
| 133 | //------------------------------------------------------------------ |
| 134 | Double_t xv=fP2*(fX*fP2 - fP0*TMath::Sqrt(1.- fP2*fP2)); //linear approxim. |
| a9a2d814 |
135 | PropagateTo(xv,d,x0); |
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136 | return 0; |
| 137 | } |
| 138 | |
| 139 | //____________________________________________________________________________ |
| 140 | Int_t AliITStrackV2:: |
| 141 | GetGlobalXYZat(Double_t xk, Double_t &x, Double_t &y, Double_t &z) const { |
| 142 | //------------------------------------------------------------------ |
| 143 | //This function returns a track position in the global system |
| 144 | //------------------------------------------------------------------ |
| 145 | Double_t dx=xk-fX; |
| 146 | Double_t f1=fP2, f2=f1 + fP4*dx; |
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147 | if (TMath::Abs(f2) >= 0.9999) { |
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148 | Int_t n=GetNumberOfClusters(); |
| 149 | if (n>kWARN) |
| 150 | cerr<<n<<" AliITStrackV2::GetGlobalXYZat: Propagation failed !\n"; |
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151 | return 0; |
| 152 | } |
| 153 | |
| 154 | Double_t r1=sqrt(1.- f1*f1), r2=sqrt(1.- f2*f2); |
| 155 | |
| 156 | Double_t yk = fP0 + dx*(f1+f2)/(r1+r2); |
| 157 | Double_t zk = fP1 + dx*(f1+f2)/(f1*r2 + f2*r1)*fP3; |
| 158 | |
| 159 | Double_t cs=TMath::Cos(fAlpha), sn=TMath::Sin(fAlpha); |
| 160 | x = xk*cs - yk*sn; |
| 161 | y = xk*sn + yk*cs; |
| 162 | z = zk; |
| 163 | |
| 164 | return 1; |
| 165 | } |
| 166 | |
| 167 | //_____________________________________________________________________________ |
| 168 | Double_t AliITStrackV2::GetPredictedChi2(const AliCluster *c) const |
| 169 | { |
| 170 | //----------------------------------------------------------------- |
| 171 | // This function calculates a predicted chi2 increment. |
| 172 | //----------------------------------------------------------------- |
| 173 | Double_t r00=c->GetSigmaY2(), r01=0., r11=c->GetSigmaZ2(); |
| 174 | r00+=fC00; r01+=fC10; r11+=fC11; |
| 175 | |
| 176 | Double_t det=r00*r11 - r01*r01; |
| 7f6ddf58 |
177 | if (TMath::Abs(det) < 1.e-30) { |
| 006b5f7f |
178 | Int_t n=GetNumberOfClusters(); |
| 7f6ddf58 |
179 | if (n>kWARN) |
| 180 | cerr<<n<<" AliKalmanTrack::GetPredictedChi2: Singular matrix !\n"; |
| 006b5f7f |
181 | return 1e10; |
| 182 | } |
| 183 | Double_t tmp=r00; r00=r11; r11=tmp; r01=-r01; |
| 184 | |
| 185 | Double_t dy=c->GetY() - fP0, dz=c->GetZ() - fP1; |
| 186 | |
| 187 | return (dy*r00*dy + 2*r01*dy*dz + dz*r11*dz)/det; |
| 188 | } |
| 189 | |
| 190 | //_____________________________________________________________________________ |
| 191 | Double_t AliITStrackV2::GetPredictedChi2(const AliCluster *c,Double_t *m, |
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192 | Double_t x0) const { |
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193 | //----------------------------------------------------------------- |
| 194 | // This function calculates a chi2 increment with a vertex contraint |
| 195 | //----------------------------------------------------------------- |
| 196 | TVectorD x(5); x(0)=fP0; x(1)=fP1; x(2)=fP2; x(3)=fP3; x(4)=fP4; |
| 197 | TMatrixD C(5,5); |
| 198 | C(0,0)=fC00; |
| 199 | C(1,0)=fC10; C(1,1)=fC11; |
| 200 | C(2,0)=fC20; C(2,1)=fC21; C(2,2)=fC22; |
| 201 | C(3,0)=fC30; C(3,1)=fC31; C(3,2)=fC32; C(3,3)=fC33; |
| 202 | C(4,0)=fC40; C(4,1)=fC41; C(4,2)=fC42; C(4,3)=fC43; C(4,4)=fC44; |
| 203 | |
| 204 | C(0,1)=C(1,0); |
| 205 | C(0,2)=C(2,0); C(1,2)=C(2,1); |
| 206 | C(0,3)=C(3,0); C(1,3)=C(3,1); C(2,3)=C(3,2); |
| 207 | C(0,4)=C(4,0); C(1,4)=C(4,1); C(2,4)=C(4,2); C(3,4)=C(4,3); |
| 208 | |
| 209 | TMatrixD H(4,5); H.UnitMatrix(); |
| 210 | Double_t dy=(c->GetY() - m[0]), dz=(c->GetZ() - m[1]); |
| 211 | |
| 212 | Double_t dr=TMath::Sqrt(fX*fX + dy*dy); |
| 213 | Double_t r =TMath::Sqrt(4/dr/dr - fP4*fP4); |
| 214 | Double_t sn=0.5*(fP4*fX + dy*r); |
| 215 | Double_t tg=0.5*fP4*dz/TMath::ASin(0.5*fP4*dr); |
| 216 | TVectorD mm(4); |
| 217 | mm(0)=m[0]=c->GetY(); mm(1)=m[1]=c->GetZ(); mm(2)=m[2]=sn; mm(3)=m[3]=tg; |
| 218 | |
| 219 | Double_t v22=0.,v33=0.; |
| 220 | //x0=0.; |
| 221 | if (x0!=0.) { |
| 222 | Double_t pp2=(1.+ GetTgl()*GetTgl())/(Get1Pt()*Get1Pt()); |
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223 | Double_t beta2=pp2/(pp2 + GetMass()*GetMass()); |
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224 | x0*=TMath::Sqrt((1.+ GetTgl()*GetTgl())/(1.- GetSnp()*GetSnp())); |
| 225 | Double_t theta2=14.1*14.1/(beta2*pp2*1e6)*x0; |
| 226 | v22 = theta2*(1.- GetSnp()*GetSnp())*(1. + GetTgl()*GetTgl()); |
| 227 | v33 = theta2*(1.+ GetTgl()*GetTgl())*(1. + GetTgl()*GetTgl()); |
| 228 | } |
| 229 | Double_t sy2=c->GetSigmaY2(), sz2=c->GetSigmaZ2(); |
| 230 | v22+=kSigmaYV*kSigmaYV/dr/dr; |
| 231 | v22+=sy2/dr/dr; |
| 232 | Double_t v20=sy2/dr; |
| 233 | |
| 234 | v33+=kSigmaZV*kSigmaZV/dr/dr; |
| 235 | v33+=sz2/dr/dr; |
| 236 | Double_t v31=sz2/dr; |
| 237 | |
| 238 | TMatrixD V(4,4); |
| 239 | V(0,0)=m[4 ]=sy2; V(0,1)=m[5 ]=0.; V(0,2)=m[6 ]=v20; V(0,3)=m[7 ]=0.; |
| 240 | V(1,0)=m[8 ]=0.; V(1,1)=m[9 ]=sz2; V(1,2)=m[10]=0.; V(1,3)=m[11]=v31; |
| 241 | V(2,0)=m[12]=v20; V(2,1)=m[13]=0.; V(2,2)=m[14]=v22; V(2,3)=m[15]=0.; |
| 242 | V(3,0)=m[16]=0.; V(3,1)=m[17]=v31; V(3,2)=m[18]=0.; V(3,3)=m[19]=v33; |
| 243 | |
| 244 | TVectorD res=x; res*=H; res-=mm; //res*=-1; |
| 245 | TMatrixD tmp(H,TMatrixD::kMult,C); |
| 246 | TMatrixD R(tmp,TMatrixD::kMult,TMatrixD(TMatrixD::kTransposed,H)); R+=V; |
| 247 | |
| 248 | Double_t det=R.Determinant(); |
| 7f6ddf58 |
249 | if (TMath::Abs(det) < 1.e-30) { |
| 006b5f7f |
250 | Int_t n=GetNumberOfClusters(); |
| 7f6ddf58 |
251 | if (n>kWARN) |
| 252 | cerr<<n<<" AliITStrackV2::GetPredictedChi2: Singular matrix !\n"; |
| 006b5f7f |
253 | return 1e10; |
| 254 | } |
| 255 | |
| 256 | R.Invert(); |
| 257 | |
| 258 | TVectorD rs=res; |
| 259 | res*=R; |
| 260 | return rs*res; |
| 261 | } |
| 262 | |
| 263 | //____________________________________________________________________________ |
| a9a2d814 |
264 | Int_t AliITStrackV2::CorrectForMaterial(Double_t d, Double_t x0) { |
| 265 | //------------------------------------------------------------------ |
| 266 | //This function corrects the track parameters for crossed material |
| 267 | //------------------------------------------------------------------ |
| 268 | Double_t p2=(1.+ GetTgl()*GetTgl())/(Get1Pt()*Get1Pt()); |
| 269 | Double_t beta2=p2/(p2 + GetMass()*GetMass()); |
| 270 | d*=TMath::Sqrt((1.+ fP3*fP3)/(1.- fP2*fP2)); |
| 271 | |
| 272 | //Multiple scattering****************** |
| 273 | if (d!=0) { |
| 274 | //Double_t theta2=14.1*14.1/(beta2*p2*1e6)*TMath::Abs(d); |
| 649ab0de |
275 | Double_t theta2=1.0259e-6*14*14/28/(beta2*p2)*TMath::Abs(d)*9.36*2.33; |
| a9a2d814 |
276 | fC22 += theta2*(1.- fP2*fP2)*(1. + fP3*fP3); |
| 277 | fC33 += theta2*(1. + fP3*fP3)*(1. + fP3*fP3); |
| 278 | fC43 += theta2*fP3*fP4*(1. + fP3*fP3); |
| 279 | fC44 += theta2*fP3*fP4*fP3*fP4; |
| 280 | } |
| 281 | |
| 282 | //Energy losses************************ |
| 283 | if (x0!=0.) { |
| 284 | d*=x0; |
| 285 | Double_t dE=0.153e-3/beta2*(log(5940*beta2/(1-beta2)) - beta2)*d; |
| 286 | fP4*=(1.- sqrt(p2+GetMass()*GetMass())/p2*dE); |
| 287 | } |
| 288 | |
| 289 | if (!Invariant()) return 0; |
| 290 | |
| 291 | return 1; |
| 292 | } |
| 293 | |
| 294 | //____________________________________________________________________________ |
| 295 | Int_t AliITStrackV2::PropagateTo(Double_t xk, Double_t d, Double_t x0) { |
| 006b5f7f |
296 | //------------------------------------------------------------------ |
| 297 | //This function propagates a track |
| 298 | //------------------------------------------------------------------ |
| 299 | Double_t x1=fX, x2=xk, dx=x2-x1; |
| 300 | Double_t f1=fP2, f2=f1 + fP4*dx; |
| a9a2d814 |
301 | if (TMath::Abs(f2) >= 0.9999) { |
| 006b5f7f |
302 | Int_t n=GetNumberOfClusters(); |
| 7f6ddf58 |
303 | if (n>kWARN) |
| 304 | cerr<<n<<" AliITStrackV2::PropagateTo: Propagation failed !\n"; |
| 006b5f7f |
305 | return 0; |
| 306 | } |
| 307 | |
| 308 | Double_t r1=sqrt(1.- f1*f1), r2=sqrt(1.- f2*f2); |
| 309 | |
| 310 | fP0 += dx*(f1+f2)/(r1+r2); |
| 311 | fP1 += dx*(f1+f2)/(f1*r2 + f2*r1)*fP3; |
| 312 | fP2 += dx*fP4; |
| 313 | |
| 314 | //f = F - 1 |
| 315 | |
| 316 | Double_t f02= dx/(r1*r1*r1); |
| 317 | Double_t f04=0.5*dx*dx/(r1*r1*r1); |
| 318 | Double_t f12= dx*fP3*f1/(r1*r1*r1); |
| 319 | Double_t f14=0.5*dx*dx*fP3*f1/(r1*r1*r1); |
| 320 | Double_t f13= dx/r1; |
| 321 | Double_t f24= dx; |
| 322 | |
| 323 | //b = C*ft |
| 324 | Double_t b00=f02*fC20 + f04*fC40, b01=f12*fC20 + f14*fC40 + f13*fC30; |
| 325 | Double_t b02=f24*fC40; |
| 326 | Double_t b10=f02*fC21 + f04*fC41, b11=f12*fC21 + f14*fC41 + f13*fC31; |
| 327 | Double_t b12=f24*fC41; |
| 328 | Double_t b20=f02*fC22 + f04*fC42, b21=f12*fC22 + f14*fC42 + f13*fC32; |
| 329 | Double_t b22=f24*fC42; |
| 330 | Double_t b40=f02*fC42 + f04*fC44, b41=f12*fC42 + f14*fC44 + f13*fC43; |
| 331 | Double_t b42=f24*fC44; |
| 332 | Double_t b30=f02*fC32 + f04*fC43, b31=f12*fC32 + f14*fC43 + f13*fC33; |
| 333 | Double_t b32=f24*fC43; |
| 334 | |
| 335 | //a = f*b = f*C*ft |
| 336 | Double_t a00=f02*b20+f04*b40,a01=f02*b21+f04*b41,a02=f02*b22+f04*b42; |
| 337 | Double_t a11=f12*b21+f14*b41+f13*b31,a12=f12*b22+f14*b42+f13*b32; |
| 338 | Double_t a22=f24*b42; |
| 339 | |
| 340 | //F*C*Ft = C + (b + bt + a) |
| 341 | fC00 += b00 + b00 + a00; |
| 342 | fC10 += b10 + b01 + a01; |
| 343 | fC20 += b20 + b02 + a02; |
| 344 | fC30 += b30; |
| 345 | fC40 += b40; |
| 346 | fC11 += b11 + b11 + a11; |
| 347 | fC21 += b21 + b12 + a12; |
| 348 | fC31 += b31; |
| 349 | fC41 += b41; |
| 350 | fC22 += b22 + b22 + a22; |
| 351 | fC32 += b32; |
| 352 | fC42 += b42; |
| 353 | |
| 354 | fX=x2; |
| 355 | |
| a9a2d814 |
356 | if (!CorrectForMaterial(d,x0)) return 0; |
| 006b5f7f |
357 | |
| 358 | return 1; |
| 359 | } |
| 360 | |
| 361 | //____________________________________________________________________________ |
| 362 | Int_t AliITStrackV2::Update(const AliCluster* c, Double_t chi2, UInt_t index) { |
| 363 | //------------------------------------------------------------------ |
| 364 | //This function updates track parameters |
| 365 | //------------------------------------------------------------------ |
| 366 | Double_t p0=fP0,p1=fP1,p2=fP2,p3=fP3,p4=fP4; |
| 367 | Double_t c00=fC00; |
| 368 | Double_t c10=fC10, c11=fC11; |
| 369 | Double_t c20=fC20, c21=fC21, c22=fC22; |
| 370 | Double_t c30=fC30, c31=fC31, c32=fC32, c33=fC33; |
| 371 | Double_t c40=fC40, c41=fC41, c42=fC42, c43=fC43, c44=fC44; |
| 372 | |
| 373 | |
| 374 | Double_t r00=c->GetSigmaY2(), r01=0., r11=c->GetSigmaZ2(); |
| 375 | r00+=fC00; r01+=fC10; r11+=fC11; |
| 376 | Double_t det=r00*r11 - r01*r01; |
| 377 | Double_t tmp=r00; r00=r11/det; r11=tmp/det; r01=-r01/det; |
| 378 | |
| 379 | Double_t k00=fC00*r00+fC10*r01, k01=fC00*r01+fC10*r11; |
| 380 | Double_t k10=fC10*r00+fC11*r01, k11=fC10*r01+fC11*r11; |
| 381 | Double_t k20=fC20*r00+fC21*r01, k21=fC20*r01+fC21*r11; |
| 382 | Double_t k30=fC30*r00+fC31*r01, k31=fC30*r01+fC31*r11; |
| 383 | Double_t k40=fC40*r00+fC41*r01, k41=fC40*r01+fC41*r11; |
| 384 | |
| 385 | Double_t dy=c->GetY() - fP0, dz=c->GetZ() - fP1; |
| 386 | Double_t sf=fP2 + k20*dy + k21*dz; |
| 7f6ddf58 |
387 | |
| 006b5f7f |
388 | fP0 += k00*dy + k01*dz; |
| 389 | fP1 += k10*dy + k11*dz; |
| 390 | fP2 = sf; |
| 391 | fP3 += k30*dy + k31*dz; |
| 392 | fP4 += k40*dy + k41*dz; |
| 393 | |
| 394 | Double_t c01=fC10, c02=fC20, c03=fC30, c04=fC40; |
| 395 | Double_t c12=fC21, c13=fC31, c14=fC41; |
| 396 | |
| 397 | fC00-=k00*fC00+k01*fC10; fC10-=k00*c01+k01*fC11; |
| 398 | fC20-=k00*c02+k01*c12; fC30-=k00*c03+k01*c13; |
| 399 | fC40-=k00*c04+k01*c14; |
| 400 | |
| 401 | fC11-=k10*c01+k11*fC11; |
| 402 | fC21-=k10*c02+k11*c12; fC31-=k10*c03+k11*c13; |
| 403 | fC41-=k10*c04+k11*c14; |
| 404 | |
| 405 | fC22-=k20*c02+k21*c12; fC32-=k20*c03+k21*c13; |
| 406 | fC42-=k20*c04+k21*c14; |
| 407 | |
| 408 | fC33-=k30*c03+k31*c13; |
| 409 | fC43-=k30*c04+k31*c14; |
| 410 | |
| 411 | fC44-=k40*c04+k41*c14; |
| 412 | |
| 413 | if (!Invariant()) { |
| 414 | fP0=p0; fP1=p1; fP2=p2; fP3=p3; fP4=p4; |
| 415 | fC00=c00; |
| 416 | fC10=c10; fC11=c11; |
| 417 | fC20=c20; fC21=c21; fC22=c22; |
| 418 | fC30=c30; fC31=c31; fC32=c32; fC33=c33; |
| 419 | fC40=c40; fC41=c41; fC42=c42; fC43=c43; fC44=c44; |
| 420 | return 0; |
| 421 | } |
| 422 | |
| 423 | Int_t n=GetNumberOfClusters(); |
| 424 | fIndex[n]=index; |
| 425 | SetNumberOfClusters(n+1); |
| 426 | SetChi2(GetChi2()+chi2); |
| 427 | |
| 428 | return 1; |
| 429 | } |
| 430 | |
| 006b5f7f |
431 | Int_t AliITStrackV2::Invariant() const { |
| 432 | //------------------------------------------------------------------ |
| 433 | // This function is for debugging purpose only |
| 434 | //------------------------------------------------------------------ |
| 7f6ddf58 |
435 | Int_t n=GetNumberOfClusters(); |
| 436 | |
| a9a2d814 |
437 | if (TMath::Abs(fP2)>=0.9999){ |
| 438 | if (n>kWARN) cout<<"AliITStrackV2::Invariant : fP2="<<fP2<<endl; |
| 439 | return 0; |
| 440 | } |
| 441 | if (fC00<=0 || fC00>9.) { |
| 442 | if (n>kWARN) cout<<"AliITStrackV2::Invariant : fC00="<<fC00<<endl; |
| 443 | return 0; |
| 444 | } |
| 445 | if (fC11<=0 || fC11>9.) { |
| 446 | if (n>kWARN) cout<<"AliITStrackV2::Invariant : fC11="<<fC11<<endl; |
| 447 | return 0; |
| 448 | } |
| 449 | if (fC22<=0 || fC22>1.) { |
| 450 | if (n>kWARN) cout<<"AliITStrackV2::Invariant : fC22="<<fC22<<endl; |
| 451 | return 0; |
| 452 | } |
| 453 | if (fC33<=0 || fC33>1.) { |
| 454 | if (n>kWARN) cout<<"AliITStrackV2::Invariant : fC33="<<fC33<<endl; |
| 455 | return 0; |
| 456 | } |
| 457 | if (fC44<=0 || fC44>6e-5) { |
| 458 | if (n>kWARN) cout<<"AliITStrackV2::Invariant : fC44="<<fC44<<endl; |
| 459 | return 0; |
| 14825d5a |
460 | } |
| 14825d5a |
461 | return 1; |
| 006b5f7f |
462 | } |
| 463 | |
| 464 | //____________________________________________________________________________ |
| a9a2d814 |
465 | Int_t AliITStrackV2::Propagate(Double_t alp,Double_t xk) { |
| 006b5f7f |
466 | //------------------------------------------------------------------ |
| 467 | //This function propagates a track |
| 468 | //------------------------------------------------------------------ |
| 469 | Double_t p0=fP0,p1=fP1,p2=fP2,p3=fP3,p4=fP4; |
| 470 | Double_t c00=fC00; |
| 471 | Double_t c10=fC10, c11=fC11; |
| 472 | Double_t c20=fC20, c21=fC21, c22=fC22; |
| 473 | Double_t c30=fC30, c31=fC31, c32=fC32, c33=fC33; |
| 474 | Double_t c40=fC40, c41=fC41, c42=fC42, c43=fC43, c44=fC44; |
| 475 | |
| 476 | |
| 477 | Double_t dalp=alp-fAlpha; |
| 478 | |
| 479 | Double_t ca=TMath::Cos(dalp), sa=TMath::Sin(dalp); |
| 480 | Double_t sf=fP2, cf=TMath::Sqrt(1.- fP2*fP2); |
| 481 | |
| 482 | Double_t pp2=fP2*ca - cf*sa; |
| a9a2d814 |
483 | if (TMath::Abs(pp2) >= 0.9999) { |
| 006b5f7f |
484 | Int_t n=GetNumberOfClusters(); |
| 7f6ddf58 |
485 | if (n>kWARN) |
| 486 | cerr<<n<<" AliITStrackV2::Propagate: Rotation failed !\n"; |
| 006b5f7f |
487 | return 0; |
| 488 | } |
| 489 | |
| 490 | fAlpha = alp; |
| 491 | if (fAlpha < -TMath::Pi()) fAlpha += 2*TMath::Pi(); |
| 492 | else if (fAlpha >= TMath::Pi()) fAlpha -= 2*TMath::Pi(); |
| 493 | |
| 494 | Double_t x1=fX, y1=fP0; |
| 495 | |
| 496 | fX = x1*ca + y1*sa; |
| 497 | fP0=-x1*sa + y1*ca; |
| 498 | fP2 = pp2; |
| 499 | |
| 500 | cf=ca + sf*sa/cf; |
| 501 | |
| a9a2d814 |
502 | if (!Invariant()) return 0; |
| 006b5f7f |
503 | |
| 504 | x1=fX; Double_t x2=xk, dx=x2-x1; |
| 505 | Double_t f1=fP2, f2=f1 + fP4*dx; |
| a9a2d814 |
506 | if (TMath::Abs(f2) >= 0.9999) { |
| 006b5f7f |
507 | Int_t n=GetNumberOfClusters(); |
| 7f6ddf58 |
508 | if (n>kWARN) |
| 509 | cerr<<n<<" AliITStrackV2::Propagate: Propagation failed !\n"; |
| 006b5f7f |
510 | return 0; |
| 511 | } |
| 512 | |
| 513 | Double_t r1=sqrt(1.- f1*f1), r2=sqrt(1.- f2*f2); |
| 514 | |
| 515 | fP0 += dx*(f1+f2)/(r1+r2); |
| 516 | fP1 += dx*(f1+f2)/(f1*r2 + f2*r1)*fP3; |
| 517 | fP2 += dx*fP4; |
| 518 | |
| 519 | //f = F - 1 |
| 520 | Double_t f02= dx/(r1*r1*r1); |
| 521 | Double_t f04=0.5*dx*dx/(r1*r1*r1); |
| 522 | Double_t f12= dx*fP3*f1/(r1*r1*r1); |
| 523 | Double_t f14=0.5*dx*dx*fP3*f1/(r1*r1*r1); |
| 524 | Double_t f13= dx/r1; |
| 525 | Double_t f24= dx; |
| 526 | /* |
| 527 | //b = C*ft |
| 528 | Double_t b00=f02*fC20 + f03*fC30, b01=f12*fC20 + f13*fC30 + f14*fC40; |
| 529 | Double_t b02=f23*fC30; |
| 530 | Double_t b10=f02*fC21 + f03*fC31, b11=f12*fC21 + f13*fC31 + f14*fC41; |
| 531 | Double_t b12=f23*fC31; |
| 532 | Double_t b20=f02*fC22 + f03*fC32, b21=f12*fC22 + f13*fC32 + f14*fC42; |
| 533 | Double_t b22=f23*fC32; |
| 534 | Double_t b30=f02*fC32 + f03*fC33, b31=f12*fC32 + f13*fC33 + f14*fC43; |
| 535 | Double_t b32=f23*fC33; |
| 536 | Double_t b40=f02*fC42 + f03*fC43, b41=f12*fC42 + f13*fC43 + f14*fC44; |
| 537 | Double_t b42=f23*fC43; |
| 538 | |
| 539 | //a = f*b = f*C*ft |
| 540 | Double_t a00=f02*b20+f03*b30,a01=f02*b21+f03*b31,a02=f02*b22+f03*b32; |
| 541 | Double_t a11=f12*b21+f13*b31+f14*b41,a12=f12*b22+f13*b32+f14*b42; |
| 542 | Double_t a22=f23*b32; |
| 543 | |
| 544 | //F*C*Ft = C + (b + bt + a) |
| 545 | fC00 += b00 + b00 + a00; |
| 546 | fC10 += b10 + b01 + a01; |
| 547 | fC20 += b20 + b02 + a02; |
| 548 | fC30 += b30; |
| 549 | fC40 += b40; |
| 550 | fC11 += b11 + b11 + a11; |
| 551 | fC21 += b21 + b12 + a12; |
| 552 | fC31 += b31; |
| 553 | fC41 += b41; |
| 554 | fC22 += b22 + b22 + a22; |
| 555 | fC32 += b32; |
| 556 | fC42 += b42; |
| 557 | */ |
| 558 | |
| 559 | TMatrixD F(5,5); F.UnitMatrix(); |
| 560 | F(0,0)=-(f1+f2)/(r1+r2)*sa + ca; F(0,2)=f02*cf; F(0,4)=f04; |
| 561 | F(1,0)=-(f1+f2)/(f1*r2 + f2*r1)*fP3*sa; F(1,2)=f12*cf; F(1,4)=f14; F(1,3)=f13; |
| 562 | F(2,0)=-fP4*sa; F(2,2)=cf; F(2,4)=f24; |
| 563 | |
| 564 | TMatrixD C(5,5); |
| 565 | C(0,0)=fC00; |
| 566 | C(1,0)=fC10; C(1,1)=fC11; |
| 567 | C(2,0)=fC20; C(2,1)=fC21; C(2,2)=fC22; |
| 568 | C(3,0)=fC30; C(3,1)=fC31; C(3,2)=fC32; C(3,3)=fC33; |
| 569 | C(4,0)=fC40; C(4,1)=fC41; C(4,2)=fC42; C(4,3)=fC43; C(4,4)=fC44; |
| 570 | |
| 571 | C(0,1)=C(1,0); |
| 572 | C(0,2)=C(2,0); C(1,2)=C(2,1); |
| 573 | C(0,3)=C(3,0); C(1,3)=C(3,1); C(2,3)=C(3,2); |
| 574 | C(0,4)=C(4,0); C(1,4)=C(4,1); C(2,4)=C(4,2); C(3,4)=C(4,3); |
| 575 | |
| 576 | TMatrixD tmp(C,TMatrixD::kMult,TMatrixD(TMatrixD::kTransposed, F)); |
| 577 | C.Mult(F,tmp); |
| 578 | |
| 579 | fC00=C(0,0); |
| 580 | fC10=C(1,0); fC11=C(1,1); |
| 581 | fC20=C(2,0); fC21=C(2,1); fC22=C(2,2); |
| 582 | fC30=C(3,0); fC31=C(3,1); fC32=C(3,2); fC33=C(3,3); |
| 583 | fC40=C(4,0); fC41=C(4,1); fC42=C(4,2); fC43=C(4,3); fC44=C(4,4); |
| 584 | |
| 006b5f7f |
585 | if (!Invariant()) { |
| 586 | fP0=p0; fP1=p1; fP2=p2; fP3=p3; fP4=p4; |
| 587 | fC00=c00; |
| 588 | fC10=c10; fC11=c11; |
| 589 | fC20=c20; fC21=c21; fC22=c22; |
| 590 | fC30=c30; fC31=c31; fC32=c32; fC33=c33; |
| 591 | fC40=c40; fC41=c41; fC42=c42; fC43=c43; fC44=c44; |
| 592 | return 0; |
| 593 | } |
| 594 | |
| 595 | fX=x2; |
| 596 | |
| 597 | return 1; |
| 598 | } |
| 599 | |
| a6a6f799 |
600 | Double_t AliITStrackV2::GetD(Double_t x, Double_t y) const { |
| 006b5f7f |
601 | //------------------------------------------------------------------ |
| a6a6f799 |
602 | // This function calculates the transverse impact parameter |
| 603 | // with respect to a point with global coordinates (x,y) |
| 006b5f7f |
604 | //------------------------------------------------------------------ |
| a6a6f799 |
605 | Double_t xt=fX, yt=fP0; |
| 606 | |
| 607 | Double_t sn=TMath::Sin(fAlpha), cs=TMath::Cos(fAlpha); |
| 608 | Double_t a = x*cs + y*sn; |
| 609 | y = -x*sn + y*cs; x=a; |
| 610 | xt-=x; yt-=y; |
| 611 | |
| 612 | sn=fP4*xt - fP2; cs=fP4*yt + TMath::Sqrt(1.- fP2*fP2); |
| 613 | a=2*(xt*fP2 - yt*TMath::Sqrt(1.- fP2*fP2))-fP4*(xt*xt + yt*yt); |
| 006b5f7f |
614 | if (fP4<0) a=-a; |
| 615 | return a/(1 + TMath::Sqrt(sn*sn + cs*cs)); |
| a9a2d814 |
616 | } |
| 006b5f7f |
617 | |
| a9a2d814 |
618 | Int_t AliITStrackV2::Improve(Double_t x0,Double_t yv,Double_t zv) { |
| 619 | //------------------------------------------------------------------ |
| 620 | //This function improves angular track parameters |
| 621 | //------------------------------------------------------------------ |
| 622 | Double_t dy=fP0-yv, dz=fP1-zv; |
| 623 | Double_t r2=fX*fX+dy*dy; |
| 624 | Double_t p2=(1.+ GetTgl()*GetTgl())/(Get1Pt()*Get1Pt()); |
| 625 | Double_t beta2=p2/(p2 + GetMass()*GetMass()); |
| 626 | x0*=TMath::Sqrt((1.+ GetTgl()*GetTgl())/(1.- GetSnp()*GetSnp())); |
| 627 | //Double_t theta2=14.1*14.1/(beta2*p2*1e6)*x0; |
| 628 | Double_t theta2=1.0259e-6*14*14/28/(beta2*p2)*x0*9.36*2.33; |
| 629 | { |
| 630 | Double_t parp=0.5*(fP4*fX + dy*TMath::Sqrt(4/r2-fP4*fP4)); |
| 631 | Double_t sigma2p = theta2*(1.- GetSnp()*GetSnp())*(1. + GetTgl()*GetTgl()); |
| 632 | sigma2p += fC00/r2*(1.- dy*dy/r2)*(1.- dy*dy/r2); |
| 633 | sigma2p += kSigmaYV*kSigmaYV/r2; |
| 634 | sigma2p += 0.25*fC44*fX*fX; |
| 635 | Double_t eps2p=sigma2p/(fC22+sigma2p); |
| 636 | fP0 += fC20/(fC22+sigma2p)*(parp-fP2); |
| 637 | fP2 = eps2p*fP2 + (1-eps2p)*parp; |
| 638 | fC22 *= eps2p; |
| 639 | fC20 *= eps2p; |
| 640 | } |
| 641 | { |
| 642 | Double_t parl=0.5*fP4*dz/TMath::ASin(0.5*fP4*TMath::Sqrt(r2)); |
| 643 | Double_t sigma2l=theta2; |
| 644 | sigma2l += fC11/r2+fC00*dy*dy*dz*dz/(r2*r2*r2); |
| 645 | sigma2l += kSigmaZV*kSigmaZV/r2; |
| 646 | Double_t eps2l=sigma2l/(fC33+sigma2l); |
| 647 | fP1 += fC31/(fC33+sigma2l)*(parl-fP3); |
| 648 | fP4 += fC43/(fC33+sigma2l)*(parl-fP3); |
| 649 | fP3 = eps2l*fP3 + (1-eps2l)*parl; |
| 650 | fC33 *= eps2l; fC43 *= eps2l; |
| 651 | fC31 *= eps2l; |
| 652 | } |
| 653 | if (!Invariant()) return 0; |
| 654 | return 1; |
| 655 | } |
| 006b5f7f |
656 | |
| a9a2d814 |
657 | /* |
| 006b5f7f |
658 | Int_t AliITStrackV2::Improve(Double_t x0,Double_t yv,Double_t zv) { |
| 659 | //------------------------------------------------------------------ |
| 660 | //This function improves angular track parameters |
| 661 | //------------------------------------------------------------------ |
| 662 | Double_t dy=fP0-yv, dz=fP1-zv; |
| 663 | Double_t r2=fX*fX+dy*dy; |
| 664 | Double_t p2=(1.+ GetTgl()*GetTgl())/(Get1Pt()*Get1Pt()); |
| 7f6ddf58 |
665 | Double_t beta2=p2/(p2 + GetMass()*GetMass()); |
| 006b5f7f |
666 | x0*=TMath::Sqrt((1.+ GetTgl()*GetTgl())/(1.- GetSnp()*GetSnp())); |
| a9a2d814 |
667 | //Double_t theta2=14.1*14.1/(beta2*p2*1e6)*x0; |
| 668 | Double_t theta2=1.0259e-6*14*14/28/(beta2*p2)*x0*9.36*2.33; |
| 006b5f7f |
669 | |
| 670 | Double_t par=0.5*(fP4*fX + dy*TMath::Sqrt(4/r2-fP4*fP4)); |
| 671 | Double_t sigma2 = theta2*(1.- GetSnp()*GetSnp())*(1. + GetTgl()*GetTgl()); |
| 672 | sigma2 += fC00/r2*(1.- dy*dy/r2)*(1.- dy*dy/r2); |
| 673 | sigma2 += kSigmaYV*kSigmaYV/r2; |
| 674 | sigma2 += 0.25*fC44*fX*fX; |
| 675 | Double_t eps2=sigma2/(fC22+sigma2), eps=TMath::Sqrt(eps2); |
| 676 | if (10*r2*fC44<fC22) { |
| 677 | fP2 = eps2*fP2 + (1-eps2)*par; |
| 678 | fC22*=eps2; fC21*=eps; fC20*=eps; fC32*=eps; fC42*=eps; |
| 679 | } |
| 680 | |
| 681 | par=0.5*fP4*dz/TMath::ASin(0.5*fP4*TMath::Sqrt(r2)); |
| 682 | sigma2=theta2; |
| 683 | sigma2 += fC11/r2+fC00*dy*dy*dz*dz/(r2*r2*r2); |
| 684 | sigma2 += kSigmaZV*kSigmaZV/r2; |
| 685 | eps2=sigma2/(fC33+sigma2); eps=TMath::Sqrt(eps2); |
| 686 | Double_t tgl=fP3; |
| 687 | fP3 = eps2*fP3 + (1-eps2)*par; |
| 688 | fC33*=eps2; fC32*=eps; fC31*=eps; fC30*=eps; fC43*=eps; |
| 689 | |
| 690 | eps=TMath::Sqrt((1+fP3*fP3)/(1+tgl*tgl)); |
| 691 | fP4*=eps; |
| 692 | fC44*=eps*eps; fC43*=eps;fC42*=eps; fC41*=eps; fC40*=eps; |
| 693 | |
| 694 | if (!Invariant()) return 0; |
| 695 | return 1; |
| 696 | } |
| 006b5f7f |
697 | */ |
| 14825d5a |
698 | void AliITStrackV2::ResetCovariance() { |
| 699 | //------------------------------------------------------------------ |
| 700 | //This function makes a track forget its history :) |
| 701 | //------------------------------------------------------------------ |
| 702 | |
| 703 | fC00*=10.; |
| 704 | fC10=0.; fC11*=10.; |
| 705 | fC20=0.; fC21=0.; fC22*=10.; |
| 706 | fC30=0.; fC31=0.; fC32=0.; fC33*=10.; |
| 707 | fC40=0.; fC41=0.; fC42=0.; fC43=0.; fC44*=10.; |
| 708 | |
| 709 | } |
| 23efe5f1 |
710 | |
| 711 | void AliITStrackV2::CookdEdx(Double_t low, Double_t up) { |
| 712 | //----------------------------------------------------------------- |
| a9a2d814 |
713 | // This function calculates dE/dX within the "low" and "up" cuts. |
| 714 | // Origin: Boris Batyunya, JINR, Boris.Batiounia@cern.ch |
| 23efe5f1 |
715 | //----------------------------------------------------------------- |
| 716 | Int_t i; |
| a9a2d814 |
717 | Int_t nc=4; |
| 23efe5f1 |
718 | // The clusters order is: SSD-2, SSD-1, SDD-2, SDD-1, SPD-2, SPD-1 |
| 719 | // Take only SSD and SDD |
| 23efe5f1 |
720 | |
| a9a2d814 |
721 | Int_t swap;//stupid sorting |
| 23efe5f1 |
722 | do { |
| 723 | swap=0; |
| 724 | for (i=0; i<nc-1; i++) { |
| 725 | if (fdEdxSample[i]<=fdEdxSample[i+1]) continue; |
| 726 | Float_t tmp=fdEdxSample[i]; |
| 727 | fdEdxSample[i]=fdEdxSample[i+1]; fdEdxSample[i+1]=tmp; |
| 728 | swap++; |
| 729 | } |
| 730 | } while (swap); |
| 731 | |
| a9a2d814 |
732 | Int_t nl=Int_t(low*nc), nu=Int_t(up*nc); //b.b. to take two lowest dEdX |
| 733 | // values from four ones choose |
| 734 | // nu=2 |
| 23efe5f1 |
735 | Float_t dedx=0; |
| a9a2d814 |
736 | for (i=nl; i<nu; i++) dedx += fdEdxSample[i]; |
| 737 | dedx /= (nu-nl); |
| 23efe5f1 |
738 | |
| 23efe5f1 |
739 | SetdEdx(dedx); |
| 740 | } |
git://git.uio.no / u / mrichter / AliRoot.git / blame