// which contains the result of the reconstruction
// and is the main set of classes for analaysis
// Origin: Christian Kuhn, IReS, Strasbourg, christian.kuhn@ires.in2p3.fr
+// Modified by: Antonin Maire,IPHC, Antonin.Maire@ires.in2p3.fr
+// and Boris Hippolyte,IPHC, hippolyt@in2p3.fr
//-------------------------------------------------------------------------
+#include <TDatabasePDG.h>
#include <TMath.h>
+#include <TVector3.h>
-#include "AliLog.h"
#include "AliESDcascade.h"
+#include "AliLog.h"
ClassImp(AliESDcascade)
-AliESDcascade::AliESDcascade() : TObject() {
+AliESDcascade::AliESDcascade() :
+ AliESDv0(),
+ fEffMassXi(TDatabasePDG::Instance()->GetParticle(kXiMinus)->Mass()),
+ fChi2Xi(1024),
+ fDcaXiDaughters(1024),
+ fPdgCodeXi(kXiMinus),
+ fBachIdx(-1)
+{
//--------------------------------------------------------------------
// Default constructor (Xi-)
//--------------------------------------------------------------------
- fPdgCode=kXiMinus;
- fEffMass=1.32131;
- fChi2=1.e+33;
- fPos[0]=fPos[1]=fPos[2]=0.;
- fPosCov[0]=fPosCov[1]=fPosCov[2]=fPosCov[3]=fPosCov[4]=fPosCov[5]=0.;
+ for (Int_t j=0; j<3; j++) {
+ fPosXi[j]=0.;
+ fBachMom[j]=0.;
+ }
+
+ fPosCovXi[0]=1024;
+ fPosCovXi[1]=fPosCovXi[2]=0.;
+ fPosCovXi[3]=1024;
+ fPosCovXi[4]=0.;
+ fPosCovXi[5]=1024;
+
+ fBachMomCov[0]=1024;
+ fBachMomCov[1]=fBachMomCov[2]=0.;
+ fBachMomCov[3]=1024;
+ fBachMomCov[4]=0.;
+ fBachMomCov[5]=1024;
+}
+
+AliESDcascade::AliESDcascade(const AliESDcascade& cas) :
+ AliESDv0(cas),
+ fEffMassXi(cas.fEffMassXi),
+ fChi2Xi(cas.fChi2Xi),
+ fDcaXiDaughters(cas.fDcaXiDaughters),
+ fPdgCodeXi(cas.fPdgCodeXi),
+ fBachIdx(cas.fBachIdx)
+{
+ //--------------------------------------------------------------------
+ // The copy constructor
+ //--------------------------------------------------------------------
+ for (int i=0; i<3; i++) {
+ fPosXi[i] = cas.fPosXi[i];
+ fBachMom[i] = cas.fBachMom[i];
+ }
+ for (int i=0; i<6; i++) {
+ fPosCovXi[i] = cas.fPosCovXi[i];
+ fBachMomCov[i] = cas.fBachMomCov[i];
+ }
+}
+
+AliESDcascade::AliESDcascade(const AliESDv0 &v,
+ const AliExternalTrackParam &t, Int_t i) :
+ AliESDv0(v),
+ fEffMassXi(TDatabasePDG::Instance()->GetParticle(kXiMinus)->Mass()),
+ fChi2Xi(1024),
+ fDcaXiDaughters(1024),
+ fPdgCodeXi(kXiMinus),
+ fBachIdx(i)
+{
+ //--------------------------------------------------------------------
+ // Main constructor (Xi-)
+ //--------------------------------------------------------------------
+
+ Double_t r[3]; t.GetXYZ(r);
+ Double_t x1=r[0], y1=r[1], z1=r[2]; // position of the bachelor
+ Double_t p[3]; t.GetPxPyPz(p);
+ Double_t px1=p[0], py1=p[1], pz1=p[2];// momentum of the bachelor track
+
+ Double_t x2,y2,z2; // position of the V0
+ v.GetXYZ(x2,y2,z2);
+ Double_t px2,py2,pz2; // momentum of V0
+ v.GetPxPyPz(px2,py2,pz2);
+
+ Double_t a2=((x1-x2)*px2+(y1-y2)*py2+(z1-z2)*pz2)/(px2*px2+py2*py2+pz2*pz2);
+
+ Double_t xm=x2+a2*px2;
+ Double_t ym=y2+a2*py2;
+ Double_t zm=z2+a2*pz2;
+
+ // position of the cascade decay
+
+ fPosXi[0]=0.5*(x1+xm); fPosXi[1]=0.5*(y1+ym); fPosXi[2]=0.5*(z1+zm);
+
+
+ // invariant mass of the cascade (default is Ximinus)
+
+ Double_t e1=TMath::Sqrt(0.13957*0.13957 + px1*px1 + py1*py1 + pz1*pz1);
+ Double_t e2=TMath::Sqrt(1.11568*1.11568 + px2*px2 + py2*py2 + pz2*pz2);
+
+ fEffMassXi=TMath::Sqrt((e1+e2)*(e1+e2)-
+ (px1+px2)*(px1+px2)-(py1+py2)*(py1+py2)-(pz1+pz2)*(pz1+pz2));
+
+
+ // momenta of the bachelor and the V0
+
+ fBachMom[0]=px1; fBachMom[1]=py1; fBachMom[2]=pz1;
+
+ // Setting pdg code and fixing charge
+ if (t.Charge()<0)
+ fPdgCodeXi = kXiMinus;
+ else
+ fPdgCodeXi = kXiPlusBar;
+
+ //PH Covariance matrices: to be calculated correctly in the future
+ fPosCovXi[0]=1024;
+ fPosCovXi[1]=fPosCovXi[2]=0.;
+ fPosCovXi[3]=1024;
+ fPosCovXi[4]=0.;
+ fPosCovXi[5]=1024;
+
+ fBachMomCov[0]=1024;
+ fBachMomCov[1]=fBachMomCov[2]=0.;
+ fBachMomCov[3]=1024;
+ fBachMomCov[4]=0.;
+ fBachMomCov[5]=1024;
+
+ fChi2Xi=1024.;
+
+}
+
+AliESDcascade& AliESDcascade::operator=(const AliESDcascade& cas)
+{
+ //--------------------------------------------------------------------
+ // The assignment operator
+ //--------------------------------------------------------------------
+
+ if(this==&cas) return *this;
+ AliESDv0::operator=(cas);
+
+ fEffMassXi = cas.fEffMassXi;
+ fChi2Xi = cas.fChi2Xi;
+ fDcaXiDaughters = cas.fDcaXiDaughters;
+ fPdgCodeXi = cas.fPdgCodeXi;
+ fBachIdx = cas.fBachIdx;
+ for (int i=0; i<3; i++) {
+ fPosXi[i] = cas.fPosXi[i];
+ fBachMom[i] = cas.fBachMom[i];
+ }
+ for (int i=0; i<6; i++) {
+ fPosCovXi[i] = cas.fPosCovXi[i];
+ fBachMomCov[i] = cas.fBachMomCov[i];
+ }
+ return *this;
}
-inline Double_t det(Double_t a00, Double_t a01, Double_t a10, Double_t a11){
- // determinant 2x2
- return a00*a11 - a01*a10;
+void AliESDcascade::Copy(TObject &obj) const {
+
+ // this overwrites the virtual TOBject::Copy()
+ // to allow run time copying without casting
+ // in AliESDEvent
+
+ if(this==&obj)return;
+ AliESDcascade *robj = dynamic_cast<AliESDcascade*>(&obj);
+ if(!robj)return; // not an AliESDcascade
+ *robj = *this;
}
-inline Double_t det (Double_t a00,Double_t a01,Double_t a02,
- Double_t a10,Double_t a11,Double_t a12,
- Double_t a20,Double_t a21,Double_t a22) {
- // determinant 3x3
- return
- a00*det(a11,a12,a21,a22)-a01*det(a10,a12,a20,a22)+a02*det(a10,a11,a20,a21);
+AliESDcascade::~AliESDcascade() {
+ //--------------------------------------------------------------------
+ // Empty destructor
+ //--------------------------------------------------------------------
}
+// Start with AliVParticle functions
+Double_t AliESDcascade::E() const {
+ //--------------------------------------------------------------------
+ // This gives the energy assuming the ChangeMassHypothesis was called
+ //--------------------------------------------------------------------
+ return E(fPdgCodeXi);
+}
+
+Double_t AliESDcascade::Y() const {
+ //--------------------------------------------------------------------
+ // This gives the energy assuming the ChangeMassHypothesis was called
+ //--------------------------------------------------------------------
+ return Y(fPdgCodeXi);
+}
+
+// Then extend AliVParticle functions
+Double_t AliESDcascade::E(Int_t pdg) const {
+ //--------------------------------------------------------------------
+ // This gives the energy with the particle hypothesis as argument
+ //--------------------------------------------------------------------
+ Double_t mass = TDatabasePDG::Instance()->GetParticle(pdg)->Mass();
+ return TMath::Sqrt(mass*mass+P()*P());
+}
+
+Double_t AliESDcascade::Y(Int_t pdg) const {
+ //--------------------------------------------------------------------
+ // This gives the rapidity with the particle hypothesis as argument
+ //--------------------------------------------------------------------
+ return 0.5*TMath::Log((E(pdg)+Pz())/(E(pdg)-Pz()+1.e-13));
+}
+
+// Now the functions for analysis consistency
+Double_t AliESDcascade::RapXi() const {
+ //--------------------------------------------------------------------
+ // This gives the pseudorapidity assuming a (Anti) Xi particle
+ //--------------------------------------------------------------------
+ return Y(kXiMinus);
+}
+
+Double_t AliESDcascade::RapOmega() const {
+ //--------------------------------------------------------------------
+ // This gives the pseudorapidity assuming a (Anti) Omega particle
+ //--------------------------------------------------------------------
+ return Y(kOmegaMinus);
+}
+
+Double_t AliESDcascade::AlphaXi() const {
+ //--------------------------------------------------------------------
+ // This gives the Armenteros-Podolanski alpha
+ //--------------------------------------------------------------------
+ TVector3 momBach(fBachMom[0],fBachMom[1],fBachMom[2]);
+ TVector3 momV0(fNmom[0]+fPmom[0],fNmom[1]+fPmom[1],fNmom[2]+fPmom[2]);
+ TVector3 momTot(Px(),Py(),Pz());
+
+ Double_t lQlBach = momBach.Dot(momTot)/momTot.Mag();
+ Double_t lQlV0 = momV0.Dot(momTot)/momTot.Mag();
+
+ return 1.-2./(1.+lQlBach/lQlV0);
+}
+
+Double_t AliESDcascade::PtArmXi() const {
+ //--------------------------------------------------------------------
+ // This gives the Armenteros-Podolanski ptarm
+ //--------------------------------------------------------------------
+ TVector3 momBach(fBachMom[0],fBachMom[1],fBachMom[2]);
+ TVector3 momTot(Px(),Py(),Pz());
+
+ return momBach.Perp(momTot);
+}
+
+// Then the older functions
Double_t AliESDcascade::ChangeMassHypothesis(Double_t &v0q, Int_t code) {
//--------------------------------------------------------------------
// This function changes the mass hypothesis for this cascade
Double_t nmass=0.13957, pmass=0.93827, ps0=0.101;
Double_t bmass=0.13957, mass =1.3213, ps =0.139;
- fPdgCode=code;
+ if (Charge()*code<0)
+ fPdgCodeXi = code;
+ else {
+ AliWarning("Chosen PDG code does not match the sign of the bachelor... Corrected !!");
+ fPdgCodeXi = -code;
+ }
- switch (code) {
- case 213:
- bmass=0.93827;
- break;
+ switch (fPdgCodeXi) {
case kXiMinus:
break;
case kXiPlusBar:
bmass=0.49368; mass=1.67245; ps=0.211;
break;
default:
- AliError("Invalide PDG code ! Assuming XiMinus's...");
- fPdgCode=kXiMinus;
+ AliError("Invalide PDG code ! Assuming a Xi particle...");
+ if (Charge()<0) {
+ fPdgCodeXi=kXiMinus;
+ }
+ else {
+ fPdgCodeXi=kXiPlusBar;
+ nmass=0.93827; pmass=0.13957;
+ }
break;
}
- Double_t pxn=fV0mom[0][0], pyn=fV0mom[0][1], pzn=fV0mom[0][2];
- Double_t pxp=fV0mom[1][0], pyp=fV0mom[1][1], pzp=fV0mom[1][2];
+ Double_t pxn=fNmom[0], pyn=fNmom[1], pzn=fNmom[2];
+ Double_t pxp=fPmom[0], pyp=fPmom[1], pzp=fPmom[2];
+
Double_t px0=pxn+pxp, py0=pyn+pyp, pz0=pzn+pzp;
Double_t p0=TMath::Sqrt(px0*px0 + py0*py0 + pz0*pz0);
Double_t pxl=px0+pxb, pyl=py0+pyb, pzl=pz0+pzb;
Double_t pl=TMath::Sqrt(pxl*pxl + pyl*pyl + pzl*pzl);
- fEffMass=TMath::Sqrt((e0+eb)*(e0+eb) - pl*pl);
+ fEffMassXi=TMath::Sqrt(((e0+eb)-pl)*((e0+eb)+pl));
Double_t beta=pl/(e0+eb);
Double_t pl0=(px0*pxl + py0*pyl + pz0*pzl)/pl;
//--------------------------------------------------------------------
// This function returns the cascade momentum (global)
//--------------------------------------------------------------------
- px=fV0mom[0][0]+fV0mom[1][0]+fBachMom[0];
- py=fV0mom[0][1]+fV0mom[1][1]+fBachMom[1];
- pz=fV0mom[0][2]+fV0mom[1][2]+fBachMom[2];
+ px=fNmom[0]+fPmom[0]+fBachMom[0];
+ py=fNmom[1]+fPmom[1]+fBachMom[1];
+ pz=fNmom[2]+fPmom[2]+fBachMom[2];
}
-void AliESDcascade::GetXYZ(Double_t &x, Double_t &y, Double_t &z) const {
+void AliESDcascade::GetXYZcascade(Double_t &x, Double_t &y, Double_t &z) const {
//--------------------------------------------------------------------
// This function returns cascade position (global)
//--------------------------------------------------------------------
- x=fPos[0];
- y=fPos[1];
- z=fPos[2];
+ x=fPosXi[0];
+ y=fPosXi[1];
+ z=fPosXi[2];
}
-Double_t AliESDcascade::GetD(Double_t x0, Double_t y0, Double_t z0) const {
+Double_t AliESDcascade::GetDcascade(Double_t x0, Double_t y0, Double_t z0) const {
//--------------------------------------------------------------------
// This function returns the cascade impact parameter
//--------------------------------------------------------------------
- Double_t x=fPos[0],y=fPos[1],z=fPos[2];
- Double_t px=fV0mom[0][0]+fV0mom[1][0]+fBachMom[0];
- Double_t py=fV0mom[0][1]+fV0mom[1][1]+fBachMom[1];
- Double_t pz=fV0mom[0][2]+fV0mom[1][2]+fBachMom[2];
+ Double_t x=fPosXi[0],y=fPosXi[1],z=fPosXi[2];
+ Double_t px=fNmom[0]+fPmom[0]+fBachMom[0];
+ Double_t py=fNmom[1]+fPmom[1]+fBachMom[1];
+ Double_t pz=fNmom[2]+fPmom[2]+fBachMom[2];
Double_t dx=(y0-y)*pz - (z0-z)*py;
Double_t dy=(x0-x)*pz - (z0-z)*px;
return d;
}
+Double_t AliESDcascade::GetCascadeCosineOfPointingAngle(Double_t refPointX, Double_t refPointY, Double_t refPointZ) const {
+ // calculates the pointing angle of the cascade wrt a reference point
+
+ Double_t momCas[3]; //momentum of the cascade
+ GetPxPyPz(momCas[0],momCas[1],momCas[2]);
+
+ Double_t deltaPos[3]; //vector between the reference point and the cascade vertex
+ deltaPos[0] = fPosXi[0] - refPointX;
+ deltaPos[1] = fPosXi[1] - refPointY;
+ deltaPos[2] = fPosXi[2] - refPointZ;
+
+ Double_t momCas2 = momCas[0]*momCas[0] + momCas[1]*momCas[1] + momCas[2]*momCas[2];
+ Double_t deltaPos2 = deltaPos[0]*deltaPos[0] + deltaPos[1]*deltaPos[1] + deltaPos[2]*deltaPos[2];
+
+ Double_t cosinePointingAngle = (deltaPos[0]*momCas[0] +
+ deltaPos[1]*momCas[1] +
+ deltaPos[2]*momCas[2] ) /
+ TMath::Sqrt(momCas2 * deltaPos2);
+
+ return cosinePointingAngle;
+}
+
+void AliESDcascade::GetPosCovXi(Double_t cov[6]) const {
+
+ for (Int_t i=0; i<6; ++i) cov[i] = fPosCovXi[i];
+}
git://git.uio.no / u / mrichter / AliRoot.git / blobdiff