Double_t AliKFParticle::fgBz = -5.; //* Bz compoment of the magnetic field
-AliKFParticle::AliKFParticle( const AliExternalTrackParam &track, Int_t PID )
+void AliKFParticle::Create( const Double_t Param[], const Double_t Cov[], Int_t Charge, Int_t PID )
{
- // Constructor from ALICE track, PID hypothesis should be provided
-
+ // Constructor from "cartesian" track, PID hypothesis should be provided
+ //
+ // Param[6] = { X, Y, Z, Px, Py, Pz } - position and momentum
+ // Cov [21] = lower-triangular part of the covariance matrix:
+ //
+ // ( 0 . . . . . )
+ // ( 1 2 . . . . )
+ // Cov. matrix = ( 3 4 5 . . . ) - numbering of covariance elements in Cov[]
+ // ( 6 7 8 9 . . )
+ // ( 10 11 12 13 14 . )
+ // ( 15 16 17 18 19 20 )
+
+
TParticlePDG* particlePDG = TDatabasePDG::Instance()->GetParticle(PID);
Double_t mass = (particlePDG) ? particlePDG->Mass() :0.13957;
+
+ AliKFParticleBase::Initialize( Param, Cov, Charge, mass );
+}
- track.GetXYZ(fP);
- track.GetPxPyPz(fP+3);
- Double_t energy = TMath::Sqrt( mass*mass + fP[3]*fP[3] + fP[4]*fP[4] + fP[5]*fP[5]);
- fP[6] = energy;
- fP[7] = 0;
- fQ = (track.GetSigned1Pt() >0 ) ?1 :-1; // fQ = track->GetSign() would do the same thing
- fNDF = 0;
- fChi2 = 0;
- fAtProductionVertex = 0;
- fIsLinearized = 0;
- fSFromDecay = 0;
- Double_t energyInv = 1./energy;
- Double_t
- h0 = fP[3]*energyInv,
- h1 = fP[4]*energyInv,
- h2 = fP[5]*energyInv;
+AliKFParticle::AliKFParticle( const AliExternalTrackParam &track, Int_t PID )
+{
+ // Constructor from ALICE track, PID hypothesis should be provided
+ track.GetXYZ(fP);
+ track.GetPxPyPz(fP+3);
+ fQ = (track.GetSigned1Pt() >0 ) ?1 :-1;
track.GetCovarianceXYZPxPyPz( fC );
-
- fC[21] = h0*fC[ 6] + h1*fC[10] + h2*fC[15];
- fC[22] = h0*fC[ 7] + h1*fC[11] + h2*fC[16];
- fC[23] = h0*fC[ 8] + h1*fC[12] + h2*fC[17];
- fC[24] = h0*fC[ 9] + h1*fC[13] + h2*fC[18];
- fC[25] = h0*fC[13] + h1*fC[14] + h2*fC[19];
- fC[26] = h0*fC[18] + h1*fC[19] + h2*fC[20];
- fC[27] = h0*h0*fC[ 9] + h1*h1*fC[14] + h2*h2*fC[20]
- + 2*(h0*h1*fC[13] + h0*h2*fC[18] + h1*h2*fC[19] );
- for( int i=28; i<36; i++ ) fC[i] = 0;
- fC[35] = 1.;
+ Create(fP,fC,fQ,PID);
}
AliKFParticle::AliKFParticle( const AliESDVertex &vertex )
void AliKFParticle::GetExternalTrackParam( const AliKFParticleBase &p, Double_t &X, Double_t &Alpha, Double_t P[5] )
{
+ // Conversion to AliExternalTrackParam parameterization
+
Double_t cosA = p.GetPx(), sinA = p.GetPy();
Double_t pt = TMath::Sqrt(cosA*cosA + sinA*sinA);
Double_t pti = 0;
}
-void AliKFParticle::GetDStoParticleALICE( const AliKFParticleBase &p,
- Double_t &DS, Double_t &DS1 )
- const
-{
- DS = DS1 = 0;
- Double_t x1, a1, x2, a2;
- Double_t par1[5], par2[5], cov[15];
- for(int i=0; i<15; i++) cov[i] = 0;
- cov[0] = cov[2] = cov[5] = cov[9] = cov[14] = .001;
- GetExternalTrackParam( *this, x1, a1, par1 );
- GetExternalTrackParam( p, x2, a2, par2 );
+Double_t AliKFParticle::GetDistanceFromVertexXY( const Double_t vtx[] ) const
+{
+ //* Calculate distance from vertex [cm] in XY-plane
+
+ Double_t mP[8], mC[36];
+ Transport( GetDStoPoint(vtx), mP, mC );
+ Double_t d[2]={ vtx[0]-mP[0], vtx[1]-mP[1] };
+ Double_t dist = TMath::Sqrt( d[0]*d[0]+d[1]*d[1] );
+ Double_t sign = d[0]*mP[3] - d[1]*mP[4];
+ return (sign>=0) ?dist :-dist;
+}
+
+Double_t AliKFParticle::GetDistanceFromVertexXY( const AliKFParticle &Vtx ) const
+{
+ //* Calculate distance from vertex [cm] in XY-plane
+
+ return GetDistanceFromVertexXY( Vtx.fP );
+}
+
+Double_t AliKFParticle::GetDistanceFromVertexXY( const AliESDVertex &Vtx ) const
+{
+ //* Calculate distance from vertex [cm] in XY-plane
+
+ return GetDistanceFromVertexXY( AliKFParticle(Vtx).fP );
+}
+
+Double_t AliKFParticle::GetDistanceFromParticleXY( const AliKFParticle &p ) const
+{
+ //* Calculate distance to other particle [cm]
+
+ Double_t dS, dS1;
+ GetDStoParticleXY( p, dS, dS1 );
+ Double_t mP[8], mC[36], mP1[8], mC1[36];
+ Transport( dS, mP, mC );
+ p.Transport( dS1, mP1, mC1 );
+ Double_t dx = mP[0]-mP1[0];
+ Double_t dy = mP[1]-mP1[1];
+ return TMath::Sqrt(dx*dx+dy*dy);
+}
+
+Double_t AliKFParticle::GetDeviationFromParticleXY( const AliKFParticle &p ) const
+{
+ //* Calculate sqrt(Chi2/ndf) deviation from other particle
+
+ Double_t dS, dS1;
+ GetDStoParticleXY( p, dS, dS1 );
+ Double_t mP1[8], mC1[36];
+ p.Transport( dS1, mP1, mC1 );
- AliExternalTrackParam t1(x1,a1, par1, cov);
- AliExternalTrackParam t2(x2,a2, par2, cov);
+ Double_t d[2]={ fP[0]-mP1[0], fP[1]-mP1[1] };
- Double_t xe1=0, xe2=0;
- t1.GetDCA( &t2, -GetFieldAlice(), xe1, xe2 );
- t1.PropagateTo( xe1, -GetFieldAlice() );
- t2.PropagateTo( xe2, -GetFieldAlice() );
+ Double_t sigmaS = .1+10.*TMath::Sqrt( (d[0]*d[0]+d[1]*d[1] )/
+ (mP1[3]*mP1[3]+mP1[4]*mP1[4] ) );
- Double_t xyz1[3], xyz2[3];
- t1.GetXYZ( xyz1 );
- t2.GetXYZ( xyz2 );
+ Double_t h[2] = { mP1[3]*sigmaS, mP1[4]*sigmaS };
- DS = GetDStoPoint( xyz1 );
- DS1 = p.GetDStoPoint( xyz2 );
+ mC1[0] +=h[0]*h[0];
+ mC1[1] +=h[1]*h[0];
+ mC1[2] +=h[1]*h[1];
+
+ return GetDeviationFromVertexXY( mP1, mC1 )*TMath::Sqrt(2./1.);
+}
+
+
+Double_t AliKFParticle::GetDeviationFromVertexXY( const Double_t v[], const Double_t Cv[] ) const
+{
+ //* Calculate sqrt(Chi2/ndf) deviation from vertex
+ //* v = [xyz], Cv=[Cxx,Cxy,Cyy,Cxz,Cyz,Czz]-covariance matrix
+
+ Double_t mP[8];
+ Double_t mC[36];
+
+ Transport( GetDStoPoint(v), mP, mC );
+
+ Double_t d[2]={ v[0]-mP[0], v[1]-mP[1] };
+
+ Double_t sigmaS = .1+10.*TMath::Sqrt( (d[0]*d[0]+d[1]*d[1] )/
+ (mP[3]*mP[3]+mP[4]*mP[4] ) );
+
+ Double_t h[2] = { mP[3]*sigmaS, mP[4]*sigmaS };
+
+ Double_t mSi[3] = { mC[0] +h[0]*h[0],
+ mC[1] +h[1]*h[0], mC[2] +h[1]*h[1] };
+
+ if( Cv ){
+ mSi[0]+=Cv[0];
+ mSi[1]+=Cv[1];
+ mSi[2]+=Cv[2];
+ }
+ Double_t s = ( mSi[0]*mSi[2] - mSi[1]*mSi[1] );
+ s = ( s > 1.E-20 ) ?1./s :0;
+
+ Double_t mS[3] = { mSi[2],
+ -mSi[1], mSi[0] };
+
+ return TMath::Sqrt( TMath::Abs(s*( ( mS[0]*d[0] + mS[1]*d[1] )*d[0]
+ +(mS[1]*d[0] + mS[2]*d[1] )*d[1] ))/1);
+}
+
+
+Double_t AliKFParticle::GetDeviationFromVertexXY( const AliKFParticle &Vtx ) const
+{
+ //* Calculate sqrt(Chi2/ndf) deviation from vertex
+ //* v = [xyz], Cv=[Cxx,Cxy,Cyy,Cxz,Cyz,Czz]-covariance matrix
+
+ return GetDeviationFromVertexXY( Vtx.fP, Vtx.fC );
+}
+
+Double_t AliKFParticle::GetDeviationFromVertexXY( const AliESDVertex &Vtx ) const
+{
+ //* Calculate sqrt(Chi2/ndf) deviation from vertex
+ //* v = [xyz], Cv=[Cxx,Cxy,Cyy,Cxz,Cyz,Czz]-covariance matrix
+
+ AliKFParticle v(Vtx);
+ return GetDeviationFromVertexXY( v.fP, v.fC );
+}
+
+
+Double_t AliKFParticle::GetAngle ( const AliKFParticle &p ) const
+{
+ //* Calculate the opening angle between two particles
+
+ Double_t dS, dS1;
+ GetDStoParticle( p, dS, dS1 );
+ Double_t mP[8], mC[36], mP1[8], mC1[36];
+ Transport( dS, mP, mC );
+ p.Transport( dS1, mP1, mC1 );
+ Double_t n = TMath::Sqrt( mP[3]*mP[3] + mP[4]*mP[4] + mP[5]*mP[5] );
+ Double_t n1= TMath::Sqrt( mP1[3]*mP1[3] + mP1[4]*mP1[4] + mP1[5]*mP1[5] );
+ n*=n1;
+ Double_t a = 0;
+ if( n>1.e-8 ) a = ( mP[3]*mP1[3] + mP[4]*mP1[4] + mP[5]*mP1[5] )/n;
+ if (TMath::Abs(a)<1.) a = TMath::ACos(a);
+ else a = (a>=0) ?0 :TMath::Pi();
+ return a;
+}
+
+Double_t AliKFParticle::GetAngleXY( const AliKFParticle &p ) const
+{
+ //* Calculate the opening angle between two particles in XY plane
+
+ Double_t dS, dS1;
+ GetDStoParticleXY( p, dS, dS1 );
+ Double_t mP[8], mC[36], mP1[8], mC1[36];
+ Transport( dS, mP, mC );
+ p.Transport( dS1, mP1, mC1 );
+ Double_t n = TMath::Sqrt( mP[3]*mP[3] + mP[4]*mP[4] );
+ Double_t n1= TMath::Sqrt( mP1[3]*mP1[3] + mP1[4]*mP1[4] );
+ n*=n1;
+ Double_t a = 0;
+ if( n>1.e-8 ) a = ( mP[3]*mP1[3] + mP[4]*mP1[4] )/n;
+ if (TMath::Abs(a)<1.) a = TMath::ACos(a);
+ else a = (a>=0) ?0 :TMath::Pi();
+ return a;
+}
+
+Double_t AliKFParticle::GetAngleRZ( const AliKFParticle &p ) const
+{
+ //* Calculate the opening angle between two particles in RZ plane
- return;
+ Double_t dS, dS1;
+ GetDStoParticle( p, dS, dS1 );
+ Double_t mP[8], mC[36], mP1[8], mC1[36];
+ Transport( dS, mP, mC );
+ p.Transport( dS1, mP1, mC1 );
+ Double_t nr = TMath::Sqrt( mP[3]*mP[3] + mP[4]*mP[4] );
+ Double_t n1r= TMath::Sqrt( mP1[3]*mP1[3] + mP1[4]*mP1[4] );
+ Double_t n = TMath::Sqrt( nr*nr + mP[5]*mP[5] );
+ Double_t n1= TMath::Sqrt( n1r*n1r + mP1[5]*mP1[5] );
+ n*=n1;
+ Double_t a = 0;
+ if( n>1.e-8 ) a = ( nr*n1r +mP[5]*mP1[5])/n;
+ if (TMath::Abs(a)<1.) a = TMath::ACos(a);
+ else a = (a>=0) ?0 :TMath::Pi();
+ return a;
}