| 006b5f7f |
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; |
| 1a947abf |
35 | Double_t AliITStrackV2::fSigmaYV = 0.005; |
| 36 | Double_t AliITStrackV2::fSigmaZV = 0.01; |
| 22b13da0 |
37 | //____________________________________________________________________________ |
| e6ba4672 |
38 | AliITStrackV2::AliITStrackV2():AliKalmanTrack(), |
| 22b13da0 |
39 | fX(0), |
| 40 | fAlpha(0), |
| 41 | fdEdx(0), |
| 42 | fP0(0), |
| 43 | fP1(0), |
| 44 | fP2(0), |
| 45 | fP3(0), |
| 46 | fP4(0), |
| 47 | fC00(0), |
| 48 | fC10(0), |
| 49 | fC11(0), |
| 50 | fC20(0), |
| 51 | fC21(0), |
| 52 | fC22(0), |
| 53 | fC30(0), |
| 54 | fC31(0), |
| 55 | fC32(0), |
| 56 | fC33(0), |
| 57 | fC40(0), |
| 58 | fC41(0), |
| 59 | fC42(0), |
| 60 | fC43(0), |
| e6ba4672 |
61 | fC44(0) |
| 62 | { |
| 22b13da0 |
63 | for(Int_t i=0; i<kMaxLayer; i++) fIndex[i]=0; |
| 64 | for(Int_t i=0; i<4; i++) fdEdxSample[i]=0; |
| 65 | } |
| 006b5f7f |
66 | //____________________________________________________________________________ |
| e1a65e92 |
67 | AliITStrackV2::AliITStrackV2(const AliTPCtrack& t) throw (const Char_t *) : |
| 68 | AliKalmanTrack(t) { |
| 006b5f7f |
69 | //------------------------------------------------------------------ |
| 9b280d80 |
70 | //Conversion TPC track -> ITS track |
| 006b5f7f |
71 | //------------------------------------------------------------------ |
| 006b5f7f |
72 | SetChi2(0.); |
| 73 | SetNumberOfClusters(0); |
| 14825d5a |
74 | |
| 7f6ddf58 |
75 | fdEdx = t.GetdEdx(); |
| 76 | SetMass(t.GetMass()); |
| 77 | |
| 006b5f7f |
78 | fAlpha = t.GetAlpha(); |
| 79 | if (fAlpha < -TMath::Pi()) fAlpha += 2*TMath::Pi(); |
| 80 | else if (fAlpha >= TMath::Pi()) fAlpha -= 2*TMath::Pi(); |
| 81 | |
| 9b280d80 |
82 | //Conversion of the track parameters |
| 006b5f7f |
83 | Double_t x,p[5]; t.GetExternalParameters(x,p); |
| 9b280d80 |
84 | fX=x; x=GetConvConst(); |
| 006b5f7f |
85 | fP0=p[0]; |
| 86 | fP1=p[1]; |
| 87 | fP2=p[2]; |
| 88 | fP3=p[3]; |
| 89 | fP4=p[4]/x; |
| 90 | |
| 9b280d80 |
91 | //Conversion of the covariance matrix |
| 006b5f7f |
92 | Double_t c[15]; t.GetExternalCovariance(c); |
| 93 | |
| 94 | fC00=c[0 ]; |
| 95 | fC10=c[1 ]; fC11=c[2 ]; |
| 96 | fC20=c[3 ]; fC21=c[4 ]; fC22=c[5 ]; |
| 97 | fC30=c[6 ]; fC31=c[7 ]; fC32=c[8 ]; fC33=c[9 ]; |
| 98 | fC40=c[10]/x; fC41=c[11]/x; fC42=c[12]/x; fC43=c[13]/x; fC44=c[14]/x/x; |
| 99 | |
| 100 | if (!Invariant()) throw "AliITStrackV2: conversion failed !\n"; |
| 649ab0de |
101 | |
| 006b5f7f |
102 | } |
| 103 | |
| 104 | //____________________________________________________________________________ |
| 105 | AliITStrackV2::AliITStrackV2(const AliITStrackV2& t) : AliKalmanTrack(t) { |
| 106 | //------------------------------------------------------------------ |
| 107 | //Copy constructor |
| 108 | //------------------------------------------------------------------ |
| 109 | fX=t.fX; |
| 110 | fAlpha=t.fAlpha; |
| 111 | fdEdx=t.fdEdx; |
| 112 | |
| 113 | fP0=t.fP0; fP1=t.fP1; fP2=t.fP2; fP3=t.fP3; fP4=t.fP4; |
| 114 | |
| 115 | fC00=t.fC00; |
| 116 | fC10=t.fC10; fC11=t.fC11; |
| 117 | fC20=t.fC20; fC21=t.fC21; fC22=t.fC22; |
| 118 | fC30=t.fC30; fC31=t.fC31; fC32=t.fC32; fC33=t.fC33; |
| 119 | fC40=t.fC40; fC41=t.fC41; fC42=t.fC42; fC43=t.fC43; fC44=t.fC44; |
| 120 | |
| 121 | Int_t n=GetNumberOfClusters(); |
| 23efe5f1 |
122 | for (Int_t i=0; i<n; i++) { |
| a9a2d814 |
123 | fIndex[i]=t.fIndex[i]; |
| 124 | if (i<4) fdEdxSample[i]=t.fdEdxSample[i]; |
| 23efe5f1 |
125 | } |
| 006b5f7f |
126 | } |
| a9a2d814 |
127 | |
| 006b5f7f |
128 | //_____________________________________________________________________________ |
| 129 | Int_t AliITStrackV2::Compare(const TObject *o) const { |
| 130 | //----------------------------------------------------------------- |
| 131 | // This function compares tracks according to the their curvature |
| 132 | //----------------------------------------------------------------- |
| 7f6ddf58 |
133 | AliITStrackV2 *t=(AliITStrackV2*)o; |
| a9a2d814 |
134 | //Double_t co=TMath::Abs(t->Get1Pt()); |
| 135 | //Double_t c =TMath::Abs(Get1Pt()); |
| 136 | Double_t co=t->GetSigmaY2()*t->GetSigmaZ2(); |
| 137 | Double_t c =GetSigmaY2()*GetSigmaZ2(); |
| 006b5f7f |
138 | if (c>co) return 1; |
| 139 | else if (c<co) return -1; |
| 140 | return 0; |
| 141 | } |
| 142 | |
| 143 | //_____________________________________________________________________________ |
| 144 | void AliITStrackV2::GetExternalCovariance(Double_t cc[15]) const { |
| 145 | //------------------------------------------------------------------------- |
| 146 | // This function returns an external representation of the covriance matrix. |
| 147 | // (See comments in AliTPCtrack.h about external track representation) |
| 148 | //------------------------------------------------------------------------- |
| 9b280d80 |
149 | Double_t a=GetConvConst(); |
| 006b5f7f |
150 | |
| 151 | cc[0 ]=fC00; |
| 152 | cc[1 ]=fC10; cc[2 ]=fC11; |
| 153 | cc[3 ]=fC20; cc[4 ]=fC21; cc[5 ]=fC22; |
| 154 | cc[6 ]=fC30; cc[7 ]=fC31; cc[8 ]=fC32; cc[9 ]=fC33; |
| 155 | cc[10]=fC40*a; cc[11]=fC41*a; cc[12]=fC42*a; cc[13]=fC43*a; cc[14]=fC44*a*a; |
| 156 | } |
| 157 | |
| 158 | //____________________________________________________________________________ |
| a9a2d814 |
159 | Int_t AliITStrackV2::PropagateToVertex(Double_t d,Double_t x0) { |
| 006b5f7f |
160 | //------------------------------------------------------------------ |
| 161 | //This function propagates a track to the minimal distance from the origin |
| 162 | //------------------------------------------------------------------ |
| 5b316485 |
163 | //Double_t xv=fP2*(fX*fP2 - fP0*TMath::Sqrt(1.- fP2*fP2)); //linear approxim. |
| 164 | Double_t tgf=-(fP4*fX - fP2)/(fP4*fP0 + TMath::Sqrt(1 - fP2*fP2)); |
| 165 | Double_t snf=tgf/TMath::Sqrt(1.+ tgf*tgf); |
| 166 | Double_t xv=(snf - fP2)/fP4 + fX; |
| 167 | return PropagateTo(xv,d,x0); |
| 006b5f7f |
168 | } |
| 169 | |
| 170 | //____________________________________________________________________________ |
| 171 | Int_t AliITStrackV2:: |
| 172 | GetGlobalXYZat(Double_t xk, Double_t &x, Double_t &y, Double_t &z) const { |
| 173 | //------------------------------------------------------------------ |
| 174 | //This function returns a track position in the global system |
| 175 | //------------------------------------------------------------------ |
| 176 | Double_t dx=xk-fX; |
| 177 | Double_t f1=fP2, f2=f1 + fP4*dx; |
| a9a2d814 |
178 | if (TMath::Abs(f2) >= 0.9999) { |
| 7f6ddf58 |
179 | Int_t n=GetNumberOfClusters(); |
| 180 | if (n>kWARN) |
| 181 | cerr<<n<<" AliITStrackV2::GetGlobalXYZat: Propagation failed !\n"; |
| 006b5f7f |
182 | return 0; |
| 183 | } |
| 184 | |
| 185 | Double_t r1=sqrt(1.- f1*f1), r2=sqrt(1.- f2*f2); |
| 186 | |
| 187 | Double_t yk = fP0 + dx*(f1+f2)/(r1+r2); |
| 188 | Double_t zk = fP1 + dx*(f1+f2)/(f1*r2 + f2*r1)*fP3; |
| 189 | |
| 190 | Double_t cs=TMath::Cos(fAlpha), sn=TMath::Sin(fAlpha); |
| 191 | x = xk*cs - yk*sn; |
| 192 | y = xk*sn + yk*cs; |
| 193 | z = zk; |
| 194 | |
| 195 | return 1; |
| 196 | } |
| 197 | |
| 198 | //_____________________________________________________________________________ |
| 199 | Double_t AliITStrackV2::GetPredictedChi2(const AliCluster *c) const |
| 200 | { |
| 201 | //----------------------------------------------------------------- |
| 202 | // This function calculates a predicted chi2 increment. |
| 203 | //----------------------------------------------------------------- |
| 204 | Double_t r00=c->GetSigmaY2(), r01=0., r11=c->GetSigmaZ2(); |
| 205 | r00+=fC00; r01+=fC10; r11+=fC11; |
| 206 | |
| 207 | Double_t det=r00*r11 - r01*r01; |
| 7f6ddf58 |
208 | if (TMath::Abs(det) < 1.e-30) { |
| 006b5f7f |
209 | Int_t n=GetNumberOfClusters(); |
| 7f6ddf58 |
210 | if (n>kWARN) |
| 211 | cerr<<n<<" AliKalmanTrack::GetPredictedChi2: Singular matrix !\n"; |
| 006b5f7f |
212 | return 1e10; |
| 213 | } |
| 214 | Double_t tmp=r00; r00=r11; r11=tmp; r01=-r01; |
| 33329428 |
215 | |
| 006b5f7f |
216 | Double_t dy=c->GetY() - fP0, dz=c->GetZ() - fP1; |
| 33329428 |
217 | |
| 006b5f7f |
218 | return (dy*r00*dy + 2*r01*dy*dz + dz*r11*dz)/det; |
| 219 | } |
| 220 | |
| 221 | //_____________________________________________________________________________ |
| 222 | Double_t AliITStrackV2::GetPredictedChi2(const AliCluster *c,Double_t *m, |
| 7f6ddf58 |
223 | Double_t x0) const { |
| 006b5f7f |
224 | //----------------------------------------------------------------- |
| 225 | // This function calculates a chi2 increment with a vertex contraint |
| 226 | //----------------------------------------------------------------- |
| 227 | TVectorD x(5); x(0)=fP0; x(1)=fP1; x(2)=fP2; x(3)=fP3; x(4)=fP4; |
| 228 | TMatrixD C(5,5); |
| 229 | C(0,0)=fC00; |
| 230 | C(1,0)=fC10; C(1,1)=fC11; |
| 231 | C(2,0)=fC20; C(2,1)=fC21; C(2,2)=fC22; |
| 232 | C(3,0)=fC30; C(3,1)=fC31; C(3,2)=fC32; C(3,3)=fC33; |
| 233 | C(4,0)=fC40; C(4,1)=fC41; C(4,2)=fC42; C(4,3)=fC43; C(4,4)=fC44; |
| 234 | |
| 235 | C(0,1)=C(1,0); |
| 236 | C(0,2)=C(2,0); C(1,2)=C(2,1); |
| 237 | C(0,3)=C(3,0); C(1,3)=C(3,1); C(2,3)=C(3,2); |
| 238 | C(0,4)=C(4,0); C(1,4)=C(4,1); C(2,4)=C(4,2); C(3,4)=C(4,3); |
| 239 | |
| 240 | TMatrixD H(4,5); H.UnitMatrix(); |
| 241 | Double_t dy=(c->GetY() - m[0]), dz=(c->GetZ() - m[1]); |
| 242 | |
| 243 | Double_t dr=TMath::Sqrt(fX*fX + dy*dy); |
| 244 | Double_t r =TMath::Sqrt(4/dr/dr - fP4*fP4); |
| 245 | Double_t sn=0.5*(fP4*fX + dy*r); |
| 246 | Double_t tg=0.5*fP4*dz/TMath::ASin(0.5*fP4*dr); |
| 247 | TVectorD mm(4); |
| 248 | mm(0)=m[0]=c->GetY(); mm(1)=m[1]=c->GetZ(); mm(2)=m[2]=sn; mm(3)=m[3]=tg; |
| 249 | |
| 250 | Double_t v22=0.,v33=0.; |
| 251 | //x0=0.; |
| 252 | if (x0!=0.) { |
| 253 | Double_t pp2=(1.+ GetTgl()*GetTgl())/(Get1Pt()*Get1Pt()); |
| 7f6ddf58 |
254 | Double_t beta2=pp2/(pp2 + GetMass()*GetMass()); |
| 006b5f7f |
255 | x0*=TMath::Sqrt((1.+ GetTgl()*GetTgl())/(1.- GetSnp()*GetSnp())); |
| 256 | Double_t theta2=14.1*14.1/(beta2*pp2*1e6)*x0; |
| 257 | v22 = theta2*(1.- GetSnp()*GetSnp())*(1. + GetTgl()*GetTgl()); |
| 258 | v33 = theta2*(1.+ GetTgl()*GetTgl())*(1. + GetTgl()*GetTgl()); |
| 259 | } |
| 260 | Double_t sy2=c->GetSigmaY2(), sz2=c->GetSigmaZ2(); |
| 1a947abf |
261 | v22+=fSigmaYV*fSigmaYV/dr/dr; |
| 006b5f7f |
262 | v22+=sy2/dr/dr; |
| 263 | Double_t v20=sy2/dr; |
| 264 | |
| 1a947abf |
265 | v33+=fSigmaZV*fSigmaZV/dr/dr; |
| 006b5f7f |
266 | v33+=sz2/dr/dr; |
| 267 | Double_t v31=sz2/dr; |
| 268 | |
| 269 | TMatrixD V(4,4); |
| 270 | V(0,0)=m[4 ]=sy2; V(0,1)=m[5 ]=0.; V(0,2)=m[6 ]=v20; V(0,3)=m[7 ]=0.; |
| 271 | V(1,0)=m[8 ]=0.; V(1,1)=m[9 ]=sz2; V(1,2)=m[10]=0.; V(1,3)=m[11]=v31; |
| 272 | V(2,0)=m[12]=v20; V(2,1)=m[13]=0.; V(2,2)=m[14]=v22; V(2,3)=m[15]=0.; |
| 273 | V(3,0)=m[16]=0.; V(3,1)=m[17]=v31; V(3,2)=m[18]=0.; V(3,3)=m[19]=v33; |
| 274 | |
| 275 | TVectorD res=x; res*=H; res-=mm; //res*=-1; |
| 276 | TMatrixD tmp(H,TMatrixD::kMult,C); |
| 277 | TMatrixD R(tmp,TMatrixD::kMult,TMatrixD(TMatrixD::kTransposed,H)); R+=V; |
| 278 | |
| 279 | Double_t det=R.Determinant(); |
| 7f6ddf58 |
280 | if (TMath::Abs(det) < 1.e-30) { |
| 006b5f7f |
281 | Int_t n=GetNumberOfClusters(); |
| 7f6ddf58 |
282 | if (n>kWARN) |
| 283 | cerr<<n<<" AliITStrackV2::GetPredictedChi2: Singular matrix !\n"; |
| 006b5f7f |
284 | return 1e10; |
| 285 | } |
| 286 | |
| 287 | R.Invert(); |
| 288 | |
| 289 | TVectorD rs=res; |
| 290 | res*=R; |
| 291 | return rs*res; |
| 292 | } |
| 293 | |
| 294 | //____________________________________________________________________________ |
| a9a2d814 |
295 | Int_t AliITStrackV2::CorrectForMaterial(Double_t d, Double_t x0) { |
| 296 | //------------------------------------------------------------------ |
| 297 | //This function corrects the track parameters for crossed material |
| 298 | //------------------------------------------------------------------ |
| 299 | Double_t p2=(1.+ GetTgl()*GetTgl())/(Get1Pt()*Get1Pt()); |
| 300 | Double_t beta2=p2/(p2 + GetMass()*GetMass()); |
| 301 | d*=TMath::Sqrt((1.+ fP3*fP3)/(1.- fP2*fP2)); |
| 302 | |
| 303 | //Multiple scattering****************** |
| 304 | if (d!=0) { |
| 33329428 |
305 | Double_t theta2=14.1*14.1/(beta2*p2*1e6)*TMath::Abs(d); |
| 306 | //Double_t theta2=1.0259e-6*14*14/28/(beta2*p2)*TMath::Abs(d)*9.36*2.33; |
| a9a2d814 |
307 | fC22 += theta2*(1.- fP2*fP2)*(1. + fP3*fP3); |
| 308 | fC33 += theta2*(1. + fP3*fP3)*(1. + fP3*fP3); |
| 309 | fC43 += theta2*fP3*fP4*(1. + fP3*fP3); |
| 310 | fC44 += theta2*fP3*fP4*fP3*fP4; |
| 311 | } |
| 312 | |
| 313 | //Energy losses************************ |
| 314 | if (x0!=0.) { |
| 315 | d*=x0; |
| 316 | Double_t dE=0.153e-3/beta2*(log(5940*beta2/(1-beta2)) - beta2)*d; |
| 317 | fP4*=(1.- sqrt(p2+GetMass()*GetMass())/p2*dE); |
| 318 | } |
| 319 | |
| 320 | if (!Invariant()) return 0; |
| 321 | |
| 322 | return 1; |
| 323 | } |
| 324 | |
| 325 | //____________________________________________________________________________ |
| 326 | Int_t AliITStrackV2::PropagateTo(Double_t xk, Double_t d, Double_t x0) { |
| 006b5f7f |
327 | //------------------------------------------------------------------ |
| 328 | //This function propagates a track |
| 329 | //------------------------------------------------------------------ |
| 330 | Double_t x1=fX, x2=xk, dx=x2-x1; |
| 331 | Double_t f1=fP2, f2=f1 + fP4*dx; |
| a9a2d814 |
332 | if (TMath::Abs(f2) >= 0.9999) { |
| 006b5f7f |
333 | Int_t n=GetNumberOfClusters(); |
| 7f6ddf58 |
334 | if (n>kWARN) |
| 335 | cerr<<n<<" AliITStrackV2::PropagateTo: Propagation failed !\n"; |
| 006b5f7f |
336 | return 0; |
| 337 | } |
| 338 | |
| f29dbb4b |
339 | // old position [SR, GSI, 17.02.2003] |
| 340 | Double_t oldX = fX, oldY = fP0, oldZ = fP1; |
| 341 | |
| 006b5f7f |
342 | Double_t r1=sqrt(1.- f1*f1), r2=sqrt(1.- f2*f2); |
| 343 | |
| 344 | fP0 += dx*(f1+f2)/(r1+r2); |
| 345 | fP1 += dx*(f1+f2)/(f1*r2 + f2*r1)*fP3; |
| 346 | fP2 += dx*fP4; |
| 347 | |
| 348 | //f = F - 1 |
| 349 | |
| 350 | Double_t f02= dx/(r1*r1*r1); |
| 351 | Double_t f04=0.5*dx*dx/(r1*r1*r1); |
| 352 | Double_t f12= dx*fP3*f1/(r1*r1*r1); |
| 353 | Double_t f14=0.5*dx*dx*fP3*f1/(r1*r1*r1); |
| 354 | Double_t f13= dx/r1; |
| 355 | Double_t f24= dx; |
| 356 | |
| 357 | //b = C*ft |
| 358 | Double_t b00=f02*fC20 + f04*fC40, b01=f12*fC20 + f14*fC40 + f13*fC30; |
| 359 | Double_t b02=f24*fC40; |
| 360 | Double_t b10=f02*fC21 + f04*fC41, b11=f12*fC21 + f14*fC41 + f13*fC31; |
| 361 | Double_t b12=f24*fC41; |
| 362 | Double_t b20=f02*fC22 + f04*fC42, b21=f12*fC22 + f14*fC42 + f13*fC32; |
| 363 | Double_t b22=f24*fC42; |
| 364 | Double_t b40=f02*fC42 + f04*fC44, b41=f12*fC42 + f14*fC44 + f13*fC43; |
| 365 | Double_t b42=f24*fC44; |
| 366 | Double_t b30=f02*fC32 + f04*fC43, b31=f12*fC32 + f14*fC43 + f13*fC33; |
| 367 | Double_t b32=f24*fC43; |
| 368 | |
| 369 | //a = f*b = f*C*ft |
| 370 | Double_t a00=f02*b20+f04*b40,a01=f02*b21+f04*b41,a02=f02*b22+f04*b42; |
| 371 | Double_t a11=f12*b21+f14*b41+f13*b31,a12=f12*b22+f14*b42+f13*b32; |
| 372 | Double_t a22=f24*b42; |
| 373 | |
| 374 | //F*C*Ft = C + (b + bt + a) |
| 375 | fC00 += b00 + b00 + a00; |
| 376 | fC10 += b10 + b01 + a01; |
| 377 | fC20 += b20 + b02 + a02; |
| 378 | fC30 += b30; |
| 379 | fC40 += b40; |
| 380 | fC11 += b11 + b11 + a11; |
| 381 | fC21 += b21 + b12 + a12; |
| 382 | fC31 += b31; |
| 383 | fC41 += b41; |
| 384 | fC22 += b22 + b22 + a22; |
| 385 | fC32 += b32; |
| 386 | fC42 += b42; |
| 387 | |
| 388 | fX=x2; |
| 389 | |
| a9a2d814 |
390 | if (!CorrectForMaterial(d,x0)) return 0; |
| 006b5f7f |
391 | |
| f29dbb4b |
392 | // Integrated Time [SR, GSI, 17.02.2003] |
| 393 | if (IsStartedTimeIntegral()) { |
| 394 | Double_t l2 = (fX-oldX)*(fX-oldX)+(fP0-oldY)*(fP0-oldY)+(fP1-oldZ)*(fP1-oldZ); |
| 395 | AddTimeStep(TMath::Sqrt(l2)); |
| 396 | } |
| 397 | // |
| 398 | |
| 006b5f7f |
399 | return 1; |
| 400 | } |
| 401 | |
| 402 | //____________________________________________________________________________ |
| 403 | Int_t AliITStrackV2::Update(const AliCluster* c, Double_t chi2, UInt_t index) { |
| 404 | //------------------------------------------------------------------ |
| 405 | //This function updates track parameters |
| 406 | //------------------------------------------------------------------ |
| 407 | Double_t p0=fP0,p1=fP1,p2=fP2,p3=fP3,p4=fP4; |
| 408 | Double_t c00=fC00; |
| 409 | Double_t c10=fC10, c11=fC11; |
| 410 | Double_t c20=fC20, c21=fC21, c22=fC22; |
| 411 | Double_t c30=fC30, c31=fC31, c32=fC32, c33=fC33; |
| 412 | Double_t c40=fC40, c41=fC41, c42=fC42, c43=fC43, c44=fC44; |
| 413 | |
| 414 | |
| 415 | Double_t r00=c->GetSigmaY2(), r01=0., r11=c->GetSigmaZ2(); |
| 416 | r00+=fC00; r01+=fC10; r11+=fC11; |
| 417 | Double_t det=r00*r11 - r01*r01; |
| 418 | Double_t tmp=r00; r00=r11/det; r11=tmp/det; r01=-r01/det; |
| 419 | |
| 420 | Double_t k00=fC00*r00+fC10*r01, k01=fC00*r01+fC10*r11; |
| 421 | Double_t k10=fC10*r00+fC11*r01, k11=fC10*r01+fC11*r11; |
| 422 | Double_t k20=fC20*r00+fC21*r01, k21=fC20*r01+fC21*r11; |
| 423 | Double_t k30=fC30*r00+fC31*r01, k31=fC30*r01+fC31*r11; |
| 424 | Double_t k40=fC40*r00+fC41*r01, k41=fC40*r01+fC41*r11; |
| 425 | |
| 426 | Double_t dy=c->GetY() - fP0, dz=c->GetZ() - fP1; |
| 427 | Double_t sf=fP2 + k20*dy + k21*dz; |
| 7f6ddf58 |
428 | |
| 006b5f7f |
429 | fP0 += k00*dy + k01*dz; |
| 430 | fP1 += k10*dy + k11*dz; |
| 431 | fP2 = sf; |
| 432 | fP3 += k30*dy + k31*dz; |
| 433 | fP4 += k40*dy + k41*dz; |
| 434 | |
| 435 | Double_t c01=fC10, c02=fC20, c03=fC30, c04=fC40; |
| 436 | Double_t c12=fC21, c13=fC31, c14=fC41; |
| 437 | |
| 438 | fC00-=k00*fC00+k01*fC10; fC10-=k00*c01+k01*fC11; |
| 439 | fC20-=k00*c02+k01*c12; fC30-=k00*c03+k01*c13; |
| 440 | fC40-=k00*c04+k01*c14; |
| 441 | |
| 442 | fC11-=k10*c01+k11*fC11; |
| 443 | fC21-=k10*c02+k11*c12; fC31-=k10*c03+k11*c13; |
| 444 | fC41-=k10*c04+k11*c14; |
| 445 | |
| 446 | fC22-=k20*c02+k21*c12; fC32-=k20*c03+k21*c13; |
| 447 | fC42-=k20*c04+k21*c14; |
| 448 | |
| 449 | fC33-=k30*c03+k31*c13; |
| 450 | fC43-=k30*c04+k31*c14; |
| 451 | |
| 452 | fC44-=k40*c04+k41*c14; |
| 453 | |
| 454 | if (!Invariant()) { |
| 455 | fP0=p0; fP1=p1; fP2=p2; fP3=p3; fP4=p4; |
| 456 | fC00=c00; |
| 457 | fC10=c10; fC11=c11; |
| 458 | fC20=c20; fC21=c21; fC22=c22; |
| 459 | fC30=c30; fC31=c31; fC32=c32; fC33=c33; |
| 460 | fC40=c40; fC41=c41; fC42=c42; fC43=c43; fC44=c44; |
| 461 | return 0; |
| 462 | } |
| 463 | |
| 464 | Int_t n=GetNumberOfClusters(); |
| 465 | fIndex[n]=index; |
| 466 | SetNumberOfClusters(n+1); |
| 467 | SetChi2(GetChi2()+chi2); |
| 468 | |
| 469 | return 1; |
| 470 | } |
| 471 | |
| 006b5f7f |
472 | Int_t AliITStrackV2::Invariant() const { |
| 473 | //------------------------------------------------------------------ |
| 474 | // This function is for debugging purpose only |
| 475 | //------------------------------------------------------------------ |
| 7f6ddf58 |
476 | Int_t n=GetNumberOfClusters(); |
| 477 | |
| a9a2d814 |
478 | if (TMath::Abs(fP2)>=0.9999){ |
| 479 | if (n>kWARN) cout<<"AliITStrackV2::Invariant : fP2="<<fP2<<endl; |
| 480 | return 0; |
| 481 | } |
| 482 | if (fC00<=0 || fC00>9.) { |
| 483 | if (n>kWARN) cout<<"AliITStrackV2::Invariant : fC00="<<fC00<<endl; |
| 484 | return 0; |
| 485 | } |
| 486 | if (fC11<=0 || fC11>9.) { |
| 487 | if (n>kWARN) cout<<"AliITStrackV2::Invariant : fC11="<<fC11<<endl; |
| 488 | return 0; |
| 489 | } |
| 490 | if (fC22<=0 || fC22>1.) { |
| 491 | if (n>kWARN) cout<<"AliITStrackV2::Invariant : fC22="<<fC22<<endl; |
| 492 | return 0; |
| 493 | } |
| 494 | if (fC33<=0 || fC33>1.) { |
| 495 | if (n>kWARN) cout<<"AliITStrackV2::Invariant : fC33="<<fC33<<endl; |
| 496 | return 0; |
| 497 | } |
| 498 | if (fC44<=0 || fC44>6e-5) { |
| 499 | if (n>kWARN) cout<<"AliITStrackV2::Invariant : fC44="<<fC44<<endl; |
| 500 | return 0; |
| 14825d5a |
501 | } |
| 14825d5a |
502 | return 1; |
| 006b5f7f |
503 | } |
| 504 | |
| 505 | //____________________________________________________________________________ |
| a9a2d814 |
506 | Int_t AliITStrackV2::Propagate(Double_t alp,Double_t xk) { |
| 006b5f7f |
507 | //------------------------------------------------------------------ |
| 508 | //This function propagates a track |
| 509 | //------------------------------------------------------------------ |
| 33329428 |
510 | Double_t alpha=fAlpha, x=fX; |
| 006b5f7f |
511 | Double_t p0=fP0,p1=fP1,p2=fP2,p3=fP3,p4=fP4; |
| 512 | Double_t c00=fC00; |
| 513 | Double_t c10=fC10, c11=fC11; |
| 514 | Double_t c20=fC20, c21=fC21, c22=fC22; |
| 515 | Double_t c30=fC30, c31=fC31, c32=fC32, c33=fC33; |
| 516 | Double_t c40=fC40, c41=fC41, c42=fC42, c43=fC43, c44=fC44; |
| 517 | |
| 33329428 |
518 | if (alp < -TMath::Pi()) alp += 2*TMath::Pi(); |
| 519 | else if (alp >= TMath::Pi()) alp -= 2*TMath::Pi(); |
| 520 | Double_t ca=TMath::Cos(alp-fAlpha), sa=TMath::Sin(alp-fAlpha); |
| 521 | Double_t sf=fP2, cf=TMath::Sqrt(1.- fP2*fP2); |
| 006b5f7f |
522 | |
| 33329428 |
523 | TMatrixD *T=0; |
| 524 | // **** rotation ********************** |
| 525 | { |
| 006b5f7f |
526 | fAlpha = alp; |
| 33329428 |
527 | fX = x*ca + p0*sa; |
| 528 | fP0= -x*sa + p0*ca; |
| 529 | fP2= sf*ca - cf*sa; |
| 530 | |
| 531 | TMatrixD C(5,5); |
| 532 | C(0,0)=c00; |
| 533 | C(1,0)=c10; C(1,1)=c11; |
| 534 | C(2,0)=c20; C(2,1)=c21; C(2,2)=c22; |
| 535 | C(3,0)=c30; C(3,1)=c31; C(3,2)=c32; C(3,3)=c33; |
| 536 | C(4,0)=c40; C(4,1)=c41; C(4,2)=c42; C(4,3)=c43; C(4,4)=c44; |
| 537 | C(0,1)=C(1,0); |
| 538 | C(0,2)=C(2,0); C(1,2)=C(2,1); |
| 539 | C(0,3)=C(3,0); C(1,3)=C(3,1); C(2,3)=C(3,2); |
| 540 | C(0,4)=C(4,0); C(1,4)=C(4,1); C(2,4)=C(4,2); C(3,4)=C(4,3); |
| 006b5f7f |
541 | |
| 33329428 |
542 | TMatrixD F(6,5); |
| 543 | F(0,0)=sa; |
| 544 | F(1,0)=ca; |
| 545 | F(2,1)=F(4,3)=F(5,4)=1; |
| 546 | F(3,2)=ca + sf/cf*sa; |
| 006b5f7f |
547 | |
| 33329428 |
548 | TMatrixD tmp(C,TMatrixD::kMult,TMatrixD(TMatrixD::kTransposed, F)); |
| 549 | T=new TMatrixD(F,TMatrixD::kMult,tmp); |
| 550 | } |
| 006b5f7f |
551 | |
| 33329428 |
552 | // **** translation ****************** |
| 553 | { |
| 554 | Double_t dx=xk-fX; |
| 006b5f7f |
555 | Double_t f1=fP2, f2=f1 + fP4*dx; |
| a9a2d814 |
556 | if (TMath::Abs(f2) >= 0.9999) { |
| 006b5f7f |
557 | Int_t n=GetNumberOfClusters(); |
| 7f6ddf58 |
558 | if (n>kWARN) |
| 559 | cerr<<n<<" AliITStrackV2::Propagate: Propagation failed !\n"; |
| 006b5f7f |
560 | return 0; |
| 561 | } |
| 33329428 |
562 | Double_t r1=TMath::Sqrt(1.- f1*f1), r2=TMath::Sqrt(1.- f2*f2); |
| 006b5f7f |
563 | |
| 33329428 |
564 | fX=xk; |
| 006b5f7f |
565 | fP0 += dx*(f1+f2)/(r1+r2); |
| 566 | fP1 += dx*(f1+f2)/(f1*r2 + f2*r1)*fP3; |
| 567 | fP2 += dx*fP4; |
| 568 | |
| 33329428 |
569 | TMatrixD F(5,6); |
| 570 | F(0,1)=F(1,2)=F(2,3)=F(3,4)=F(4,5)=1; |
| 571 | F(0,3)=dx/(r1+r2)*(2+(f1+f2)*(f2/r2+f1/r1)/(r1+r2)); |
| 572 | F(0,5)=dx*dx/(r1+r2)*(1+(f1+f2)*f2/(r1+r2)); |
| 573 | F(1,3)=dx*fP3/(f1*r2 + f2*r1)*(2-(f1+f2)*(r2-f1*f2/r2+r1-f2*f1/r1)/(f1*r2 + f2*r1)); |
| 574 | F(1,4)=dx*(f1+f2)/(f1*r2 + f2*r1); |
| 575 | F(1,5)=dx*dx*fP3/(f1*r2 + f2*r1)*(1-(f1+f2)*(-f1*f2/r2+r1)/(f1*r2 + f2*r1)); |
| 576 | F(2,5)=dx; |
| 577 | F(0,0)=-1/(r1+r2)*((f1+f2)+dx*fP4*(1+(f1+f2)/(r1+r2)*f2/r2)); |
| 578 | F(1,0)=-fP3/(f1*r2 + f2*r1)*((f1+f2)+dx*fP4*(1+(f1+f2)/(f1*r2 + f2*r1)*(f1*f2/r2-r1))); |
| 579 | F(2,0)=-fP4; |
| 580 | |
| 581 | TMatrixD tmp(*T,TMatrixD::kMult,TMatrixD(TMatrixD::kTransposed, F)); |
| 582 | delete T; |
| 583 | TMatrixD C(F,TMatrixD::kMult,tmp); |
| 006b5f7f |
584 | |
| 585 | fC00=C(0,0); |
| 586 | fC10=C(1,0); fC11=C(1,1); |
| 587 | fC20=C(2,0); fC21=C(2,1); fC22=C(2,2); |
| 588 | fC30=C(3,0); fC31=C(3,1); fC32=C(3,2); fC33=C(3,3); |
| 589 | fC40=C(4,0); fC41=C(4,1); fC42=C(4,2); fC43=C(4,3); fC44=C(4,4); |
| 590 | |
| 006b5f7f |
591 | if (!Invariant()) { |
| 33329428 |
592 | fAlpha=alpha; |
| 593 | fX=x; |
| 006b5f7f |
594 | fP0=p0; fP1=p1; fP2=p2; fP3=p3; fP4=p4; |
| 595 | fC00=c00; |
| 596 | fC10=c10; fC11=c11; |
| 597 | fC20=c20; fC21=c21; fC22=c22; |
| 598 | fC30=c30; fC31=c31; fC32=c32; fC33=c33; |
| 599 | fC40=c40; fC41=c41; fC42=c42; fC43=c43; fC44=c44; |
| 600 | return 0; |
| 601 | } |
| 33329428 |
602 | } |
| 006b5f7f |
603 | |
| 604 | return 1; |
| 605 | } |
| 606 | |
| a6a6f799 |
607 | Double_t AliITStrackV2::GetD(Double_t x, Double_t y) const { |
| 006b5f7f |
608 | //------------------------------------------------------------------ |
| a6a6f799 |
609 | // This function calculates the transverse impact parameter |
| 610 | // with respect to a point with global coordinates (x,y) |
| 006b5f7f |
611 | //------------------------------------------------------------------ |
| a6a6f799 |
612 | Double_t xt=fX, yt=fP0; |
| 613 | |
| 614 | Double_t sn=TMath::Sin(fAlpha), cs=TMath::Cos(fAlpha); |
| 615 | Double_t a = x*cs + y*sn; |
| 616 | y = -x*sn + y*cs; x=a; |
| 617 | xt-=x; yt-=y; |
| 618 | |
| 619 | sn=fP4*xt - fP2; cs=fP4*yt + TMath::Sqrt(1.- fP2*fP2); |
| 620 | a=2*(xt*fP2 - yt*TMath::Sqrt(1.- fP2*fP2))-fP4*(xt*xt + yt*yt); |
| 006b5f7f |
621 | if (fP4<0) a=-a; |
| 622 | return a/(1 + TMath::Sqrt(sn*sn + cs*cs)); |
| a9a2d814 |
623 | } |
| 006b5f7f |
624 | |
| a9a2d814 |
625 | Int_t AliITStrackV2::Improve(Double_t x0,Double_t yv,Double_t zv) { |
| 626 | //------------------------------------------------------------------ |
| 627 | //This function improves angular track parameters |
| 628 | //------------------------------------------------------------------ |
| 629 | Double_t dy=fP0-yv, dz=fP1-zv; |
| 630 | Double_t r2=fX*fX+dy*dy; |
| 631 | Double_t p2=(1.+ GetTgl()*GetTgl())/(Get1Pt()*Get1Pt()); |
| 632 | Double_t beta2=p2/(p2 + GetMass()*GetMass()); |
| 633 | x0*=TMath::Sqrt((1.+ GetTgl()*GetTgl())/(1.- GetSnp()*GetSnp())); |
| 634 | //Double_t theta2=14.1*14.1/(beta2*p2*1e6)*x0; |
| 635 | Double_t theta2=1.0259e-6*14*14/28/(beta2*p2)*x0*9.36*2.33; |
| 636 | { |
| 637 | Double_t parp=0.5*(fP4*fX + dy*TMath::Sqrt(4/r2-fP4*fP4)); |
| 638 | Double_t sigma2p = theta2*(1.- GetSnp()*GetSnp())*(1. + GetTgl()*GetTgl()); |
| 639 | sigma2p += fC00/r2*(1.- dy*dy/r2)*(1.- dy*dy/r2); |
| 1a947abf |
640 | sigma2p += fSigmaYV*fSigmaYV/r2; |
| a9a2d814 |
641 | sigma2p += 0.25*fC44*fX*fX; |
| 642 | Double_t eps2p=sigma2p/(fC22+sigma2p); |
| 643 | fP0 += fC20/(fC22+sigma2p)*(parp-fP2); |
| 644 | fP2 = eps2p*fP2 + (1-eps2p)*parp; |
| 645 | fC22 *= eps2p; |
| 646 | fC20 *= eps2p; |
| 647 | } |
| 648 | { |
| 649 | Double_t parl=0.5*fP4*dz/TMath::ASin(0.5*fP4*TMath::Sqrt(r2)); |
| 650 | Double_t sigma2l=theta2; |
| 651 | sigma2l += fC11/r2+fC00*dy*dy*dz*dz/(r2*r2*r2); |
| 1a947abf |
652 | sigma2l += fSigmaZV*fSigmaZV/r2; |
| a9a2d814 |
653 | Double_t eps2l=sigma2l/(fC33+sigma2l); |
| 654 | fP1 += fC31/(fC33+sigma2l)*(parl-fP3); |
| 655 | fP4 += fC43/(fC33+sigma2l)*(parl-fP3); |
| 656 | fP3 = eps2l*fP3 + (1-eps2l)*parl; |
| 657 | fC33 *= eps2l; fC43 *= eps2l; |
| 658 | fC31 *= eps2l; |
| 659 | } |
| 660 | if (!Invariant()) return 0; |
| 661 | return 1; |
| 662 | } |
| 006b5f7f |
663 | |
| a9a2d814 |
664 | /* |
| 006b5f7f |
665 | Int_t AliITStrackV2::Improve(Double_t x0,Double_t yv,Double_t zv) { |
| 666 | //------------------------------------------------------------------ |
| 667 | //This function improves angular track parameters |
| 668 | //------------------------------------------------------------------ |
| 669 | Double_t dy=fP0-yv, dz=fP1-zv; |
| 670 | Double_t r2=fX*fX+dy*dy; |
| 671 | Double_t p2=(1.+ GetTgl()*GetTgl())/(Get1Pt()*Get1Pt()); |
| 7f6ddf58 |
672 | Double_t beta2=p2/(p2 + GetMass()*GetMass()); |
| 006b5f7f |
673 | x0*=TMath::Sqrt((1.+ GetTgl()*GetTgl())/(1.- GetSnp()*GetSnp())); |
| a9a2d814 |
674 | //Double_t theta2=14.1*14.1/(beta2*p2*1e6)*x0; |
| 675 | Double_t theta2=1.0259e-6*14*14/28/(beta2*p2)*x0*9.36*2.33; |
| 006b5f7f |
676 | |
| 677 | Double_t par=0.5*(fP4*fX + dy*TMath::Sqrt(4/r2-fP4*fP4)); |
| 678 | Double_t sigma2 = theta2*(1.- GetSnp()*GetSnp())*(1. + GetTgl()*GetTgl()); |
| 679 | sigma2 += fC00/r2*(1.- dy*dy/r2)*(1.- dy*dy/r2); |
| 680 | sigma2 += kSigmaYV*kSigmaYV/r2; |
| 681 | sigma2 += 0.25*fC44*fX*fX; |
| 682 | Double_t eps2=sigma2/(fC22+sigma2), eps=TMath::Sqrt(eps2); |
| 683 | if (10*r2*fC44<fC22) { |
| 684 | fP2 = eps2*fP2 + (1-eps2)*par; |
| 685 | fC22*=eps2; fC21*=eps; fC20*=eps; fC32*=eps; fC42*=eps; |
| 686 | } |
| 687 | |
| 688 | par=0.5*fP4*dz/TMath::ASin(0.5*fP4*TMath::Sqrt(r2)); |
| 689 | sigma2=theta2; |
| 690 | sigma2 += fC11/r2+fC00*dy*dy*dz*dz/(r2*r2*r2); |
| 691 | sigma2 += kSigmaZV*kSigmaZV/r2; |
| 692 | eps2=sigma2/(fC33+sigma2); eps=TMath::Sqrt(eps2); |
| 693 | Double_t tgl=fP3; |
| 694 | fP3 = eps2*fP3 + (1-eps2)*par; |
| 695 | fC33*=eps2; fC32*=eps; fC31*=eps; fC30*=eps; fC43*=eps; |
| 696 | |
| 697 | eps=TMath::Sqrt((1+fP3*fP3)/(1+tgl*tgl)); |
| 698 | fP4*=eps; |
| 699 | fC44*=eps*eps; fC43*=eps;fC42*=eps; fC41*=eps; fC40*=eps; |
| 700 | |
| 701 | if (!Invariant()) return 0; |
| 702 | return 1; |
| 703 | } |
| 006b5f7f |
704 | */ |
| 14825d5a |
705 | void AliITStrackV2::ResetCovariance() { |
| 706 | //------------------------------------------------------------------ |
| 707 | //This function makes a track forget its history :) |
| 708 | //------------------------------------------------------------------ |
| 709 | |
| 710 | fC00*=10.; |
| 711 | fC10=0.; fC11*=10.; |
| 712 | fC20=0.; fC21=0.; fC22*=10.; |
| 713 | fC30=0.; fC31=0.; fC32=0.; fC33*=10.; |
| 714 | fC40=0.; fC41=0.; fC42=0.; fC43=0.; fC44*=10.; |
| 715 | |
| 716 | } |
| 23efe5f1 |
717 | |
| 718 | void AliITStrackV2::CookdEdx(Double_t low, Double_t up) { |
| 719 | //----------------------------------------------------------------- |
| a9a2d814 |
720 | // This function calculates dE/dX within the "low" and "up" cuts. |
| 721 | // Origin: Boris Batyunya, JINR, Boris.Batiounia@cern.ch |
| 23efe5f1 |
722 | //----------------------------------------------------------------- |
| 723 | Int_t i; |
| a9a2d814 |
724 | Int_t nc=4; |
| 23efe5f1 |
725 | // The clusters order is: SSD-2, SSD-1, SDD-2, SDD-1, SPD-2, SPD-1 |
| 726 | // Take only SSD and SDD |
| 23efe5f1 |
727 | |
| a9a2d814 |
728 | Int_t swap;//stupid sorting |
| 23efe5f1 |
729 | do { |
| 730 | swap=0; |
| 731 | for (i=0; i<nc-1; i++) { |
| 732 | if (fdEdxSample[i]<=fdEdxSample[i+1]) continue; |
| 733 | Float_t tmp=fdEdxSample[i]; |
| 734 | fdEdxSample[i]=fdEdxSample[i+1]; fdEdxSample[i+1]=tmp; |
| 735 | swap++; |
| 736 | } |
| 737 | } while (swap); |
| 738 | |
| a9a2d814 |
739 | Int_t nl=Int_t(low*nc), nu=Int_t(up*nc); //b.b. to take two lowest dEdX |
| 740 | // values from four ones choose |
| 741 | // nu=2 |
| 23efe5f1 |
742 | Float_t dedx=0; |
| a9a2d814 |
743 | for (i=nl; i<nu; i++) dedx += fdEdxSample[i]; |
| 744 | dedx /= (nu-nl); |
| 23efe5f1 |
745 | |
| 23efe5f1 |
746 | SetdEdx(dedx); |
| 747 | } |
git://git.uio.no / u / mrichter / AliRoot.git / blame