}
Bool_t AliExternalTrackParam::CorrectForMeanMaterial
-(Double_t xOverX0, Double_t xTimesRho, Double_t mass,
-Double_t (*Bethe)(Double_t)) {
+(Double_t xOverX0, Double_t xTimesRho, Double_t mass, Bool_t anglecorr,
+ Double_t (*Bethe)(Double_t)) {
//------------------------------------------------------------------
// This function corrects the track parameters for the crossed material.
// "xOverX0" - X/X0, the thickness in units of the radiation length.
Double_t &fC43=fC[13];
Double_t &fC44=fC[14];
+ //Apply angle correction, if requested
+ if(anglecorr) {
+ Double_t angle=TMath::Sqrt((1.+ fP3*fP3)/(1.- fP2*fP2));
+ xOverX0 *=angle;
+ xTimesRho *=angle;
+ }
+
Double_t p=GetP();
Double_t p2=p*p;
Double_t beta2=p2/(p2 + mass*mass);
}
-
-
-Bool_t Local2GlobalMomentum(Double_t p[3],Double_t alpha) {
- //----------------------------------------------------------------
- // This function performs local->global transformation of the
- // track momentum.
- // When called, the arguments are:
- // p[0] = 1/pt of the track;
- // p[1] = sine of local azim. angle of the track momentum;
- // p[2] = tangent of the track momentum dip angle;
- // alpha - rotation angle.
- // The result is returned as:
- // p[0] = px
- // p[1] = py
- // p[2] = pz
- // Results for (nearly) straight tracks are meaningless !
- //----------------------------------------------------------------
- if (TMath::Abs(p[0])<=kAlmost0) return kFALSE;
- if (TMath::Abs(p[1])> kAlmost1) return kFALSE;
-
- Double_t pt=1./TMath::Abs(p[0]);
- Double_t cs=TMath::Cos(alpha), sn=TMath::Sin(alpha);
- Double_t r=TMath::Sqrt(1 - p[1]*p[1]);
- p[0]=pt*(r*cs - p[1]*sn); p[1]=pt*(p[1]*cs + r*sn); p[2]=pt*p[2];
-
- return kTRUE;
-}
-
-Bool_t Local2GlobalPosition(Double_t r[3],Double_t alpha) {
- //----------------------------------------------------------------
- // This function performs local->global transformation of the
- // track position.
- // When called, the arguments are:
- // r[0] = local x
- // r[1] = local y
- // r[2] = local z
- // alpha - rotation angle.
- // The result is returned as:
- // r[0] = global x
- // r[1] = global y
- // r[2] = global z
- //----------------------------------------------------------------
- Double_t cs=TMath::Cos(alpha), sn=TMath::Sin(alpha), x=r[0];
- r[0]=x*cs - r[1]*sn; r[1]=x*sn + r[1]*cs;
-
- return kTRUE;
-}
-
void AliExternalTrackParam::GetDirection(Double_t d[3]) const {
//----------------------------------------------------------------
// This function returns a unit vector along the track direction
d[2]=fP[3]/norm;
}
-Bool_t AliExternalTrackParam::GetPxPyPz(Double_t *p) const {
+Bool_t AliExternalTrackParam::GetPxPyPz(Double_t p[3]) const {
//---------------------------------------------------------------------
// This function returns the global track momentum components
// Results for (nearly) straight tracks are meaningless !
}
Double_t AliExternalTrackParam::Px() const {
- // return x-component of momentum
+ //---------------------------------------------------------------------
+ // Returns x-component of momentum
+ // Result for (nearly) straight tracks is meaningless !
+ //---------------------------------------------------------------------
- Double_t p[3];
+ Double_t p[3]={kVeryBig,kVeryBig,kVeryBig};
GetPxPyPz(p);
return p[0];
}
Double_t AliExternalTrackParam::Py() const {
- // return y-component of momentum
+ //---------------------------------------------------------------------
+ // Returns y-component of momentum
+ // Result for (nearly) straight tracks is meaningless !
+ //---------------------------------------------------------------------
- Double_t p[3];
+ Double_t p[3]={kVeryBig,kVeryBig,kVeryBig};
GetPxPyPz(p);
return p[1];
}
Double_t AliExternalTrackParam::Pz() const {
- // return z-component of momentum
+ //---------------------------------------------------------------------
+ // Returns z-component of momentum
+ // Result for (nearly) straight tracks is meaningless !
+ //---------------------------------------------------------------------
- Double_t p[3];
+ Double_t p[3]={kVeryBig,kVeryBig,kVeryBig};
GetPxPyPz(p);
return p[2];
}
+Double_t AliExternalTrackParam::Xv() const {
+ //---------------------------------------------------------------------
+ // Returns x-component of first track point
+ //---------------------------------------------------------------------
+
+ Double_t r[3]={0.,0.,0.};
+ GetXYZ(r);
+
+ return r[0];
+}
+
+Double_t AliExternalTrackParam::Yv() const {
+ //---------------------------------------------------------------------
+ // Returns y-component of first track point
+ //---------------------------------------------------------------------
+
+ Double_t r[3]={0.,0.,0.};
+ GetXYZ(r);
+
+ return r[1];
+}
+
+Double_t AliExternalTrackParam::Zv() const {
+ //---------------------------------------------------------------------
+ // Returns z-component of first track point
+ //---------------------------------------------------------------------
+
+ Double_t r[3]={0.,0.,0.};
+ GetXYZ(r);
+
+ return r[2];
+}
+
Double_t AliExternalTrackParam::Theta() const {
// return theta angle of momentum
- return TMath::ATan2(Pt(), Pz());
+ return 0.5*TMath::Pi() - TMath::ATan(fP[3]);
}
Double_t AliExternalTrackParam::Phi() const {
- // return phi angle of momentum
-
- Double_t p[3];
- GetPxPyPz(p);
+ //---------------------------------------------------------------------
+ // Returns the azimuthal angle of momentum
+ // 0 <= phi < 2*pi
+ //---------------------------------------------------------------------
- return TMath::ATan2(p[1], p[0]);
+ Double_t phi=TMath::ASin(fP[2]) + fAlpha;
+ if (phi<0.) phi+=2.*TMath::Pi();
+ else if (phi>=2.*TMath::Pi()) phi-=2.*TMath::Pi();
+
+ return phi;
}
Double_t AliExternalTrackParam::M() const {
Double_t res = fP[2]+dx*crv;
return res;
}
+
+Bool_t AliExternalTrackParam::GetDistance(AliExternalTrackParam *param2, Double_t x, Double_t dist[3], Double_t bz){
+ //------------------------------------------------------------------------
+ // Get the distance between two tracks at the local position x
+ // working in the local frame of this track.
+ // Origin : Marian.Ivanov@cern.ch
+ //-----------------------------------------------------------------------
+ Double_t xyz[3];
+ Double_t xyz2[3];
+ xyz[0]=x;
+ if (!GetYAt(x,bz,xyz[1])) return kFALSE;
+ if (!GetZAt(x,bz,xyz[2])) return kFALSE;
+ //
+ //
+ if (TMath::Abs(GetAlpha()-param2->GetAlpha())<kAlmost0){
+ xyz2[0]=x;
+ if (!param2->GetYAt(x,bz,xyz2[1])) return kFALSE;
+ if (!param2->GetZAt(x,bz,xyz2[2])) return kFALSE;
+ }else{
+ //
+ Double_t xyz1[3];
+ Double_t dfi = param2->GetAlpha()-GetAlpha();
+ Double_t ca = TMath::Cos(dfi), sa = TMath::Sin(dfi);
+ xyz2[0] = xyz[0]*ca+xyz[1]*sa;
+ xyz2[1] = -xyz[0]*sa+xyz[1]*ca;
+ //
+ xyz1[0]=xyz2[0];
+ if (!param2->GetYAt(xyz2[0],bz,xyz1[1])) return kFALSE;
+ if (!param2->GetZAt(xyz2[0],bz,xyz1[2])) return kFALSE;
+ //
+ xyz2[0] = xyz1[0]*ca-xyz1[1]*sa;
+ xyz2[1] = +xyz1[0]*sa+xyz1[1]*ca;
+ xyz2[2] = xyz1[2];
+ }
+ dist[0] = xyz[0]-xyz2[0];
+ dist[1] = xyz[1]-xyz2[1];
+ dist[2] = xyz[2]-xyz2[2];
+
+ return kTRUE;
+}
git://git.uio.no / u / mrichter / AliRoot.git / blobdiff