* provided "as is" without express or implied warranty. *
**************************************************************************/
-//-------------------------------------------------------------------------
+///////////////////////////////////////////////////////////////////////////
// Implementation of the ITS track class
//
// Origin: Iouri Belikov, CERN, Jouri.Belikov@cern.ch
// dEdx analysis by: Boris Batyunya, JINR, Boris.Batiounia@cern.ch
-//-------------------------------------------------------------------------
-
-#include <TMatrixD.h>
-
+///////////////////////////////////////////////////////////////////////////
#include <TMath.h>
#include "AliCluster.h"
-#include "AliTPCtrack.h"
#include "AliESDtrack.h"
#include "AliITStrackV2.h"
+#include "AliStrLine.h"
ClassImp(AliITStrackV2)
fC42(0),
fC43(0),
fC44(0),
- fNUsed(0),
- fNSkipped(0),
- fNDeadZone(0),
- fDeadZoneProbability(0),
- fReconstructed(kFALSE),
- fConstrain(kFALSE),
fESDtrack(0)
{
- for(Int_t i=0; i<kMaxLayer; i++) {fIndex[i]=0;fClIndex[i]=-1;}
+ for(Int_t i=0; i<2*kMaxLayer; i++) fIndex[i]=-1;
for(Int_t i=0; i<4; i++) fdEdxSample[i]=0;
- for(Int_t i=0; i<6; i++) { fNy[i]=0; fNz[i]=0; fNormQ[i]=0; fNormChi2[i]=1000;}
- for(Int_t i=0; i<12; i++) {fDy[i]=0; fDz[i]=0; fSigmaY[i]=0; fSigmaZ[i]=0; fChi2MIP[i]=0;}
- fD[0]=0; fD[1]=0;
- fExpQ=40;
- fdEdxMismatch=0;
- fChi22=0;
}
-//____________________________________________________________________________
-AliITStrackV2::AliITStrackV2(const AliTPCtrack& t) throw (const Char_t *) :
-AliKalmanTrack(t) {
- //------------------------------------------------------------------
- //Conversion TPC track -> ITS track
- //------------------------------------------------------------------
- SetChi2(0.);
- SetNumberOfClusters(0);
-
- fdEdx = t.GetdEdx();
- SetMass(t.GetMass());
-
- fAlpha = t.GetAlpha();
- if (fAlpha < -TMath::Pi()) fAlpha += 2*TMath::Pi();
- else if (fAlpha >= TMath::Pi()) fAlpha -= 2*TMath::Pi();
-
- //Conversion of the track parameters
- Double_t x,p[5]; t.GetExternalParameters(x,p);
- fX=x; x=GetConvConst();
- fP0=p[0];
- fP1=p[1];
- fP2=p[2];
- fP3=p[3];
- fP4=p[4]/x;
-
- //Conversion of the covariance matrix
- Double_t c[15]; t.GetExternalCovariance(c);
-
- fC00=c[0 ];
- fC10=c[1 ]; fC11=c[2 ];
- fC20=c[3 ]; fC21=c[4 ]; fC22=c[5 ];
- fC30=c[6 ]; fC31=c[7 ]; fC32=c[8 ]; fC33=c[9 ];
- fC40=c[10]/x; fC41=c[11]/x; fC42=c[12]/x; fC43=c[13]/x; fC44=c[14]/x/x;
-
- for(Int_t i=0; i<6; i++) { fNy[i]=0; fNz[i]=0; fNormQ[i]=0; fNormChi2[i]=1000;}
- for(Int_t i=0; i<12; i++) {fDy[i]=0; fDz[i]=0; fSigmaY[i]=0; fSigmaZ[i]=0; }
- fConstrain=kFALSE;
- //
- if (!Invariant()) throw "AliITStrackV2: conversion failed !\n";
-
-}
//____________________________________________________________________________
AliITStrackV2::AliITStrackV2(AliESDtrack& t,Bool_t c) throw (const Char_t *) :
//Conversion of the track parameters
Double_t x,p[5];
- if (c) t.GetConstrainedExternalParameters(x,p);
+ if (c) t.GetConstrainedExternalParameters(fAlpha,x,p);
else t.GetExternalParameters(x,p);
- fX=x; x=GetConvConst();
+ fX=x;
fP0=p[0];
- fP1=p[1];
+ fP1=p[1]; SaveLocalConvConst();
fP2=p[2];
- fP3=p[3];
+ fP3=p[3]; x=GetLocalConvConst();
fP4=p[4]/x;
//Conversion of the covariance matrix
SetIntegratedLength(t.GetIntegratedLength());
}
fESDtrack=&t;
- fNUsed = 0;
- fReconstructed = kFALSE;
- fNSkipped =0;
- fNDeadZone = 0;
- fDeadZoneProbability = 0;
- for(Int_t i=0; i<6; i++) {fClIndex[i]=-1; fNy[i]=0; fNz[i]=0; fNormQ[i]=0; fNormChi2[i]=1000;}
- for(Int_t i=0; i<12; i++) {fDy[i]=0; fDz[i]=0; fSigmaY[i]=0; fSigmaZ[i]=0;fChi2MIP[i]=0;}
- fD[0]=0; fD[1]=0;
- fExpQ=40;
- fConstrain = kFALSE;
- fdEdxMismatch=0;
- fChi22 =0;
-
- //if (!Invariant()) throw "AliITStrackV2: conversion failed !\n";
+ // if (!Invariant()) throw "AliITStrackV2: conversion failed !\n";
+ for(Int_t i=0; i<4; i++) fdEdxSample[i]=0;
}
-void AliITStrackV2::UpdateESDtrack(ULong_t flags) {
+void AliITStrackV2::UpdateESDtrack(ULong_t flags) const {
fESDtrack->UpdateTrackParams(this,flags);
- if (flags == AliESDtrack::kITSin) fESDtrack->SetITSChi2MIP(fChi2MIP);
-}
-void AliITStrackV2::SetConstrainedESDtrack(Double_t chi2) {
- fESDtrack->SetConstrainedTrackParams(this,chi2);
}
//____________________________________________________________________________
fC30=t.fC30; fC31=t.fC31; fC32=t.fC32; fC33=t.fC33;
fC40=t.fC40; fC41=t.fC41; fC42=t.fC42; fC43=t.fC43; fC44=t.fC44;
- Int_t n=GetNumberOfClusters();
- for (Int_t i=0; i<n; i++) {
- fIndex[i]=t.fIndex[i];
- if (i<4) fdEdxSample[i]=t.fdEdxSample[i];
- }
+ Int_t i;
+ for (i=0; i<2*kMaxLayer; i++) fIndex[i]=t.fIndex[i];
+ for (i=0; i<4; i++) fdEdxSample[i]=t.fdEdxSample[i];
+
fESDtrack=t.fESDtrack;
- fNUsed = t.fNUsed;
- fReconstructed = t.fReconstructed;
- fNSkipped = t.fNSkipped;
- fNDeadZone = t.fNDeadZone;
- fDeadZoneProbability = t.fDeadZoneProbability;
- fLab = t.fLab;
- fFakeRatio = t.fFakeRatio;
- fdEdxMismatch = t.fdEdxMismatch;
- fChi22 = t.fChi22;
-
-
- fD[0]=t.fD[0]; fD[1]=t.fD[1];
- fExpQ= t.fExpQ;
- for(Int_t i=0; i<6; i++) {
- fClIndex[i]= t.fClIndex[i]; fNy[i]=t.fNy[i]; fNz[i]=t.fNz[i]; fNormQ[i]=t.fNormQ[i]; fNormChi2[i] = t.fNormChi2[i];
- }
- for(Int_t i=0; i<12; i++) {fDy[i]=t.fDy[i]; fDz[i]=t.fDz[i];
- fSigmaY[i]=t.fSigmaY[i]; fSigmaZ[i]=t.fSigmaZ[i];fChi2MIP[i]=t.fChi2MIP[i];}
- fConstrain = t.fConstrain;
- //memcpy(fDy,t.fDy,6*sizeof(Float_t));
- //memcpy(fDz,t.fDz,6*sizeof(Float_t));
- //memcpy(fSigmaY,t.fSigmaY,6*sizeof(Float_t));
- //memcpy(fSigmaZ,t.fSigmaZ,6*sizeof(Float_t));
- //memcpy(fChi2MIP,t.fChi2MIP,12*sizeof(Float_t));
}
//_____________________________________________________________________________
AliITStrackV2 *t=(AliITStrackV2*)o;
//Double_t co=TMath::Abs(t->Get1Pt());
//Double_t c =TMath::Abs(Get1Pt());
- Double_t co=t->GetSigmaY2()*t->GetSigmaZ2()*(0.5+TMath::Sqrt(0.5*t->fD[0]*t->fD[0]+t->fD[1]*t->fD[1]));
- Double_t c =GetSigmaY2()*GetSigmaZ2()*(0.5+TMath::Sqrt(0.5*fD[0]*fD[0]+fD[1]*fD[1]));
+ Double_t co=t->GetSigmaY2()*t->GetSigmaZ2();
+ Double_t c =GetSigmaY2()*GetSigmaZ2();
if (c>co) return 1;
else if (c<co) return -1;
return 0;
// This function returns an external representation of the covriance matrix.
// (See comments in AliTPCtrack.h about external track representation)
//-------------------------------------------------------------------------
- Double_t a=GetConvConst();
+ Double_t a=GetLocalConvConst();
cc[0 ]=fC00;
cc[1 ]=fC10; cc[2 ]=fC11;
return 1;
}
+//_____________________________________________________________________________
+void AliITStrackV2::ApproximateHelixWithLine(Double_t xk, AliStrLine *line)
+{
+ //------------------------------------------------------------
+ // Approximate the track (helix) with a straight line tangent to the
+ // helix in the point defined by r (F. Prino, prino@to.infn.it)
+ //------------------------------------------------------------
+ Double_t mom[3];
+ Double_t azim = TMath::ASin(fP2)+fAlpha;
+ Double_t theta = TMath::Pi()/2. - TMath::ATan(fP3);
+ mom[0] = TMath::Sin(theta)*TMath::Cos(azim);
+ mom[1] = TMath::Sin(theta)*TMath::Sin(azim);
+ mom[2] = TMath::Cos(theta);
+ Double_t pos[3];
+ GetGlobalXYZat(xk,pos[0],pos[1],pos[2]);
+ line->SetP0(pos);
+ line->SetCd(mom);
+}
//_____________________________________________________________________________
Double_t AliITStrackV2::GetPredictedChi2(const AliCluster *c) const
{
return (dy*r00*dy + 2*r01*dy*dz + dz*r11*dz)/det;
}
-Double_t AliITStrackV2::GetPredictedChi2MI(Double_t cy, Double_t cz, Double_t cerry, Double_t cerrz) const
-{
- //-----------------------------------------------------------------
- // This function calculates a predicted chi2 increment.
- //-----------------------------------------------------------------
- Double_t r00=cerry*cerry, r01=0., r11=cerrz*cerrz;
- r00+=fC00; r01+=fC10; r11+=fC11;
- //
- Double_t det=r00*r11 - r01*r01;
- if (TMath::Abs(det) < 1.e-30) {
- Int_t n=GetNumberOfClusters();
- if (n>kWARN)
- Warning("GetPredictedChi2","Singular matrix (%d) !\n",n);
- return 1e10;
- }
- Double_t tmp=r00; r00=r11; r11=tmp; r01=-r01;
-
- Double_t dy=cy - fP0, dz=cz - fP1;
-
- return (dy*r00*dy + 2*r01*dy*dz + dz*r11*dz)/det;
-}
-
//____________________________________________________________________________
Int_t AliITStrackV2::CorrectForMaterial(Double_t d, Double_t x0) {
//------------------------------------------------------------------
//This function corrects the track parameters for crossed material
//------------------------------------------------------------------
- // Double_t p2=(1.+ GetTgl()*GetTgl())/(Get1Pt()*Get1Pt());
Double_t p2=(1.+ fP3*fP3)/(Get1Pt()*Get1Pt());
- Double_t et = p2 + GetMass()*GetMass();
- Double_t beta2=p2/et;
- et = sqrt(et);
+ Double_t beta2=p2/(p2 + GetMass()*GetMass());
d*=TMath::Sqrt((1.+ fP3*fP3)/(1.- fP2*fP2));
- //d*=TMath::Sqrt(1.+ fP3*fP3 +fP2*fP2/(1.- fP2*fP2));
//Multiple scattering******************
if (d!=0) {
//Energy losses************************
if (x0!=0.) {
d*=x0;
- // Double_t dE=0.153e-3/beta2*(log(5940*beta2/(1-beta2)) - beta2)*d;
- //Double_t dE=0;
- Double_t dE = 0.265*0.153e-3*(39.2-55.6*beta2+28.7*beta2*beta2+27.41/beta2)*d;
- /*
- if (beta2/(1-beta2)>3.5*3.5){
+ Double_t dE=0.153e-3/beta2*(log(5940*beta2/(1-beta2)) - beta2)*d;
+ if (beta2/(1-beta2)>3.5*3.5)
dE=0.153e-3/beta2*(log(3.5*5940)+0.5*log(beta2/(1-beta2)) - beta2)*d;
- }
- else{
- dE=0.153e-3/beta2*(log(5940*beta2/(1-beta2)) - beta2)*d;
- dE+=0.06e-3/(beta2*beta2)*d;
- }
- */
- fP4*=(1.- et/p2*dE);
- Double_t delta44 = (dE*fP4*et/p2);
- delta44*=delta44;
- fC44+= delta44/400.;
+
+ fP4*=(1.- TMath::Sqrt(p2+GetMass()*GetMass())/p2*dE);
}
if (!Invariant()) return 0;
//------------------------------------------------------------------
Double_t x1=fX, x2=xk, dx=x2-x1;
Double_t f1=fP2, f2=f1 + fP4*dx;
- if (TMath::Abs(f2) >= 0.9999) {
- Int_t n=GetNumberOfClusters();
- if (n>kWARN)
- Warning("PropagateTo","Propagation failed !\n",n);
+ if (TMath::Abs(f2) >= 0.98) {
+ // MI change - don't propagate highly inclined tracks
+ // covariance matrix distorted
+ //Int_t n=GetNumberOfClusters();
+ //if (n>kWARN)
+ // Warning("PropagateTo","Propagation failed !\n",n);
return 0;
}
+ Double_t lcc=GetLocalConvConst();
// old position [SR, GSI, 17.02.2003]
Double_t oldX = fX, oldY = fP0, oldZ = fP1;
fX=x2;
+ //Change of the magnetic field *************
+ SaveLocalConvConst();
+ fP4*=lcc/GetLocalConvConst();
+
if (!CorrectForMaterial(d,x0)) return 0;
// Integrated Time [SR, GSI, 17.02.2003]
Double_t k40=fC40*r00+fC41*r01, k41=fC40*r01+fC41*r11;
Double_t dy=c->GetY() - fP0, dz=c->GetZ() - fP1;
- Int_t layer = (index & 0xf0000000) >> 28;
- fDy[layer] = dy;
- fDz[layer] = dz;
- fSigmaY[layer] = TMath::Sqrt(c->GetSigmaY2()+fC00);
- fSigmaZ[layer] = TMath::Sqrt(c->GetSigmaZ2()+fC11);
-
Double_t sf=fP2 + k20*dy + k21*dz;
fP0 += k00*dy + k01*dz;
return 1;
}
-//____________________________________________________________________________
-Int_t AliITStrackV2::UpdateMI(Double_t cy, Double_t cz, Double_t cerry, Double_t cerrz, Double_t chi2,UInt_t index) {
- //------------------------------------------------------------------
- //This function updates track parameters
- //------------------------------------------------------------------
- Double_t p0=fP0,p1=fP1,p2=fP2,p3=fP3,p4=fP4;
- Double_t c00=fC00;
- Double_t c10=fC10, c11=fC11;
- Double_t c20=fC20, c21=fC21, c22=fC22;
- Double_t c30=fC30, c31=fC31, c32=fC32, c33=fC33;
- Double_t c40=fC40, c41=fC41, c42=fC42, c43=fC43, c44=fC44;
-
-
- Double_t r00=cerry*cerry, r01=0., r11=cerrz*cerrz;
- r00+=fC00; r01+=fC10; r11+=fC11;
- Double_t det=r00*r11 - r01*r01;
- Double_t tmp=r00; r00=r11/det; r11=tmp/det; r01=-r01/det;
-
-
- Double_t k00=fC00*r00+fC10*r01, k01=fC00*r01+fC10*r11;
- Double_t k10=fC10*r00+fC11*r01, k11=fC10*r01+fC11*r11;
- Double_t k20=fC20*r00+fC21*r01, k21=fC20*r01+fC21*r11;
- Double_t k30=fC30*r00+fC31*r01, k31=fC30*r01+fC31*r11;
- Double_t k40=fC40*r00+fC41*r01, k41=fC40*r01+fC41*r11;
-
- Double_t dy=cy - fP0, dz=cz - fP1;
- Int_t layer = (index & 0xf0000000) >> 28;
- fDy[layer] = dy;
- fDz[layer] = dz;
- fSigmaY[layer] = TMath::Sqrt(cerry*cerry+fC00);
- fSigmaZ[layer] = TMath::Sqrt(cerrz*cerrz+fC11);
-
- Double_t sf=fP2 + k20*dy + k21*dz;
-
- fP0 += k00*dy + k01*dz;
- fP1 += k10*dy + k11*dz;
- fP2 = sf;
- fP3 += k30*dy + k31*dz;
- fP4 += k40*dy + k41*dz;
-
- Double_t c01=fC10, c02=fC20, c03=fC30, c04=fC40;
- Double_t c12=fC21, c13=fC31, c14=fC41;
-
- fC00-=k00*fC00+k01*fC10; fC10-=k00*c01+k01*fC11;
- fC20-=k00*c02+k01*c12; fC30-=k00*c03+k01*c13;
- fC40-=k00*c04+k01*c14;
-
- fC11-=k10*c01+k11*fC11;
- fC21-=k10*c02+k11*c12; fC31-=k10*c03+k11*c13;
- fC41-=k10*c04+k11*c14;
-
- fC22-=k20*c02+k21*c12; fC32-=k20*c03+k21*c13;
- fC42-=k20*c04+k21*c14;
-
- fC33-=k30*c03+k31*c13;
- fC43-=k30*c04+k31*c14;
-
- fC44-=k40*c04+k41*c14;
-
- if (!Invariant()) {
- fP0=p0; fP1=p1; fP2=p2; fP3=p3; fP4=p4;
- fC00=c00;
- fC10=c10; fC11=c11;
- fC20=c20; fC21=c21; fC22=c22;
- fC30=c30; fC31=c31; fC32=c32; fC33=c33;
- fC40=c40; fC41=c41; fC42=c42; fC43=c43; fC44=c44;
- return 0;
- }
-
- if (chi2<0) return 1;
- Int_t n=GetNumberOfClusters();
- fIndex[n]=index;
- SetNumberOfClusters(n+1);
- SetChi2(GetChi2()+chi2);
-
- return 1;
-}
-
Int_t AliITStrackV2::Invariant() const {
//------------------------------------------------------------------
// This function is for debugging purpose only
Double_t ca=TMath::Cos(alp-fAlpha), sa=TMath::Sin(alp-fAlpha);
Double_t sf=fP2, cf=TMath::Sqrt(1.- fP2*fP2);
- TMatrixD *T=0;
// **** rotation **********************
{
fAlpha = alp;
fP0= -x*sa + p0*ca;
fP2= sf*ca - cf*sa;
- static TMatrixD C(5,5);
- C(0,0)=c00;
- C(1,0)=c10; C(1,1)=c11;
- C(2,0)=c20; C(2,1)=c21; C(2,2)=c22;
- C(3,0)=c30; C(3,1)=c31; C(3,2)=c32; C(3,3)=c33;
- C(4,0)=c40; C(4,1)=c41; C(4,2)=c42; C(4,3)=c43; C(4,4)=c44;
- C(0,1)=C(1,0);
- C(0,2)=C(2,0); C(1,2)=C(2,1);
- C(0,3)=C(3,0); C(1,3)=C(3,1); C(2,3)=C(3,2);
- C(0,4)=C(4,0); C(1,4)=C(4,1); C(2,4)=C(4,2); C(3,4)=C(4,3);
-
-
- static TMatrixD F(6,5);
- F(0,0)=sa;
- F(1,0)=ca;
- F(2,1)=F(4,3)=F(5,4)=1;
- F(3,2)=ca + sf/cf*sa;
-
- //TMatrixD tmp(C,TMatrixD::kMult,TMatrixD(TMatrixD::kTransposed, F));
-
- static TMatrixD Ft(5,6);
- Ft(0,0)=sa;
- Ft(0,1)=ca;
- Ft(1,2)=Ft(3,4)=Ft(4,5)=1;
- Ft(2,3)=ca + sf/cf*sa;
-
- TMatrixD tmp(C,TMatrixD::kMult,Ft);
- T=new TMatrixD(F,TMatrixD::kMult,tmp);
-
-
+ Double_t rr=(ca+sf/cf*sa);
+
+ fC00 *= (ca*ca);
+ fC10 *= ca;
+ fC20 *= ca*rr;
+ fC30 *= ca;
+ fC40 *= ca;
+ //fC11 = fC11;
+ fC21 *= rr;
+ //fC31 = fC31;
+ //fC41 = fC41;
+ fC22 *= rr*rr;
+ fC32 *= rr;
+ fC42 *= rr;
+ //fC33=fC33;
+ //fC43=fC43;
+ //fC44=fC44;
+
}
// **** translation ******************
{
Double_t dx=xk-fX;
Double_t f1=fP2, f2=f1 + fP4*dx;
- if (TMath::Abs(f2) >= 0.9999) {
- Int_t n=GetNumberOfClusters();
- if (n>kWARN)
- Warning("Propagate","Propagation failed (%d) !\n",n);
+ if (TMath::Abs(f2) >= 0.98) {
+ // don't propagate highly inclined tracks MI
return 0;
}
+ // Int_t n=GetNumberOfClusters();
+ // if (n>kWARN)
+ // Warning("Propagate","Propagation failed (%d) !\n",n);
+ // return 0;
+ //}
+ Double_t lcc=GetLocalConvConst();
+
Double_t r1=TMath::Sqrt(1.- f1*f1), r2=TMath::Sqrt(1.- f2*f2);
-
+
fX=xk;
fP0 += dx*(f1+f2)/(r1+r2);
fP1 += dx*(f1+f2)/(f1*r2 + f2*r1)*fP3;
fP2 += dx*fP4;
- static TMatrixD F(5,6);
- F(0,1)=F(1,2)=F(2,3)=F(3,4)=F(4,5)=1;
- F(0,3)=dx/(r1+r2)*(2+(f1+f2)*(f2/r2+f1/r1)/(r1+r2));
- F(0,5)=dx*dx/(r1+r2)*(1+(f1+f2)*f2/(r1+r2));
- F(1,3)=dx*fP3/(f1*r2 + f2*r1)*(2-(f1+f2)*(r2-f1*f2/r2+r1-f2*f1/r1)/(f1*r2 + f2*r1));
- F(1,4)=dx*(f1+f2)/(f1*r2 + f2*r1);
- F(1,5)=dx*dx*fP3/(f1*r2 + f2*r1)*(1-(f1+f2)*(-f1*f2/r2+r1)/(f1*r2 + f2*r1));
- F(2,5)=dx;
- F(0,0)=-1/(r1+r2)*((f1+f2)+dx*fP4*(1+(f1+f2)/(r1+r2)*f2/r2));
- F(1,0)=-fP3/(f1*r2 + f2*r1)*((f1+f2)+dx*fP4*(1+(f1+f2)/(f1*r2 + f2*r1)*(f1*f2/r2-r1)));
- F(2,0)=-fP4;
-
- TMatrixD tmp(*T,TMatrixD::kMult,TMatrixD(TMatrixD::kTransposed, F));
- delete T;
- TMatrixD C(F,TMatrixD::kMult,tmp);
-
- fC00=C(0,0);
- fC10=C(1,0); fC11=C(1,1);
- fC20=C(2,0); fC21=C(2,1); fC22=C(2,2);
- fC30=C(3,0); fC31=C(3,1); fC32=C(3,2); fC33=C(3,3);
- fC40=C(4,0); fC41=C(4,1); fC42=C(4,2); fC43=C(4,3); fC44=C(4,4);
+ //Change of the magnetic field *************
+ SaveLocalConvConst();
+ fP4*=lcc/GetLocalConvConst();
+
+ //f = F - 1
+
+ Double_t f02= dx/(r1*r1*r1);
+ Double_t f04=0.5*dx*dx/(r1*r1*r1);
+ Double_t f12= dx*fP3*f1/(r1*r1*r1);
+ Double_t f14=0.5*dx*dx*fP3*f1/(r1*r1*r1);
+ Double_t f13= dx/r1;
+ Double_t f24= dx;
+
+ //b = C*ft
+ Double_t b00=f02*fC20 + f04*fC40, b01=f12*fC20 + f14*fC40 + f13*fC30;
+ Double_t b02=f24*fC40;
+ Double_t b10=f02*fC21 + f04*fC41, b11=f12*fC21 + f14*fC41 + f13*fC31;
+ Double_t b12=f24*fC41;
+ Double_t b20=f02*fC22 + f04*fC42, b21=f12*fC22 + f14*fC42 + f13*fC32;
+ Double_t b22=f24*fC42;
+ Double_t b40=f02*fC42 + f04*fC44, b41=f12*fC42 + f14*fC44 + f13*fC43;
+ Double_t b42=f24*fC44;
+ Double_t b30=f02*fC32 + f04*fC43, b31=f12*fC32 + f14*fC43 + f13*fC33;
+ Double_t b32=f24*fC43;
+
+ //a = f*b = f*C*ft
+ Double_t a00=f02*b20+f04*b40,a01=f02*b21+f04*b41,a02=f02*b22+f04*b42;
+ Double_t a11=f12*b21+f14*b41+f13*b31,a12=f12*b22+f14*b42+f13*b32;
+ Double_t a22=f24*b42;
+
+ //F*C*Ft = C + (b + bt + a)
+ fC00 += b00 + b00 + a00;
+ fC10 += b10 + b01 + a01;
+ fC20 += b20 + b02 + a02;
+ fC30 += b30;
+ fC40 += b40;
+ fC11 += b11 + b11 + a11;
+ fC21 += b21 + b12 + a12;
+ fC31 += b31;
+ fC41 += b41;
+ fC22 += b22 + b22 + a22;
+ fC32 += b32;
+ fC42 += b42;
if (!Invariant()) {
fAlpha=alpha;
}
-
-Int_t AliITStrackV2::GetProlongationFast(Double_t alp, Double_t xk,Double_t &y, Double_t &z)
-{
- //-----------------------------------------------------------------------------
- //get fast prolongation
- //-----------------------------------------------------------------------------
- Double_t ca=TMath::Cos(alp-fAlpha), sa=TMath::Sin(alp-fAlpha);
- Double_t cf=TMath::Sqrt(1.- fP2*fP2);
- // **** rotation **********************
- y= -fX*sa + fP0*ca;
- // **** translation ******************
- Double_t dx = xk- fX*ca - fP0*sa;
- Double_t f1=fP2*ca - cf*sa, f2=f1 + fP4*dx;
- if (TMath::Abs(f2) >= 0.9999) {
- return 0;
- }
- Double_t r1=TMath::Sqrt(1.- f1*f1), r2=TMath::Sqrt(1.- f2*f2);
- y += dx*(f1+f2)/(r1+r2);
- z = fP1+dx*(f1+f2)/(f1*r2 + f2*r1)*fP3;
- return 1;
-}
-
-
Double_t AliITStrackV2::GetD(Double_t x, Double_t y) const {
//------------------------------------------------------------------
// This function calculates the transverse impact parameter
Double_t theta2=14.1*14.1/(beta2*p2*1e6)*x0;
//Double_t theta2=1.0259e-6*14*14/28/(beta2*p2)*x0*9.36*2.33;
{
- Double_t parp=0.5*(fP4*fX + dy*TMath::Sqrt(4/r2-fP4*fP4));
+ Double_t dummy=4/r2-fP4*fP4;
+ if (dummy < 0) return 0;
+ Double_t parp=0.5*(fP4*fX + dy*TMath::Sqrt(dummy));
Double_t sigma2p = theta2*(1.- GetSnp()*GetSnp())*(1. + GetTgl()*GetTgl());
sigma2p += fC00/r2*(1.- dy*dy/r2)*(1.- dy*dy/r2);
sigma2p += ers[1]*ers[1]/r2;
return 1;
}
-/*
-Int_t AliITStrackV2::Improve(Double_t x0,Double_t yv,Double_t zv) {
- //------------------------------------------------------------------
- //This function improves angular track parameters
- //------------------------------------------------------------------
- Double_t dy=fP0-yv, dz=fP1-zv;
- Double_t r2=fX*fX+dy*dy;
- Double_t p2=(1.+ GetTgl()*GetTgl())/(Get1Pt()*Get1Pt());
- Double_t beta2=p2/(p2 + GetMass()*GetMass());
- x0*=TMath::Sqrt((1.+ GetTgl()*GetTgl())/(1.- GetSnp()*GetSnp()));
- //Double_t theta2=14.1*14.1/(beta2*p2*1e6)*x0;
- Double_t theta2=1.0259e-6*14*14/28/(beta2*p2)*x0*9.36*2.33;
-
- Double_t par=0.5*(fP4*fX + dy*TMath::Sqrt(4/r2-fP4*fP4));
- Double_t sigma2 = theta2*(1.- GetSnp()*GetSnp())*(1. + GetTgl()*GetTgl());
- sigma2 += fC00/r2*(1.- dy*dy/r2)*(1.- dy*dy/r2);
- sigma2 += kSigmaYV*kSigmaYV/r2;
- sigma2 += 0.25*fC44*fX*fX;
- Double_t eps2=sigma2/(fC22+sigma2), eps=TMath::Sqrt(eps2);
- if (10*r2*fC44<fC22) {
- fP2 = eps2*fP2 + (1-eps2)*par;
- fC22*=eps2; fC21*=eps; fC20*=eps; fC32*=eps; fC42*=eps;
- }
-
- par=0.5*fP4*dz/TMath::ASin(0.5*fP4*TMath::Sqrt(r2));
- sigma2=theta2;
- sigma2 += fC11/r2+fC00*dy*dy*dz*dz/(r2*r2*r2);
- sigma2 += kSigmaZV*kSigmaZV/r2;
- eps2=sigma2/(fC33+sigma2); eps=TMath::Sqrt(eps2);
- Double_t tgl=fP3;
- fP3 = eps2*fP3 + (1-eps2)*par;
- fC33*=eps2; fC32*=eps; fC31*=eps; fC30*=eps; fC43*=eps;
-
- eps=TMath::Sqrt((1+fP3*fP3)/(1+tgl*tgl));
- fP4*=eps;
- fC44*=eps*eps; fC43*=eps;fC42*=eps; fC41*=eps; fC40*=eps;
-
- if (!Invariant()) return 0;
- return 1;
-}
-*/
void AliITStrackV2::ResetCovariance() {
//------------------------------------------------------------------
//This function makes a track forget its history :)
SetdEdx(dedx);
}
+
+Double_t AliITStrackV2::
+PropagateToDCA(AliKalmanTrack *p, Double_t d, Double_t x0) {
+ //--------------------------------------------------------------
+ // Propagates this track and the argument track to the position of the
+ // distance of closest approach.
+ // Returns the (weighed !) distance of closest approach.
+ //--------------------------------------------------------------
+ Double_t xthis, xp, dca;
+ {
+ //Temporary solution
+ Double_t b=1./GetLocalConvConst()/kB2C;
+ AliExternalTrackParam dummy1(*this), dummy2(*p);
+ dca=dummy1.GetDCA(&dummy2,b,xthis,xp);
+ }
+ if (!PropagateTo(xthis,d,x0)) {
+ //AliWarning(" propagation failed !");
+ return 1e+33;
+ }
+
+ if (!p->PropagateTo(xp,d,x0)) {
+ //AliWarning(" propagation failed !";
+ return 1e+33;
+ }
+
+ return dca;
+}
+
+Double_t AliITStrackV2::Get1Pt() const {
+ //--------------------------------------------------------------
+ // Returns the inverse Pt (1/GeV/c)
+ // (or 1/"most probable pt", if the field is too weak)
+ //--------------------------------------------------------------
+ if (TMath::Abs(GetLocalConvConst()) > kVeryBigConvConst)
+ return 1./kMostProbableMomentum/TMath::Sqrt(1.+ GetTgl()*GetTgl());
+ return (TMath::Sign(1e-9,fP4) + fP4)*GetLocalConvConst();
+}
git://git.uio.no / u / mrichter / AliRoot.git / blobdiff