// @(#)root/physics:$Name: $:$Id: TLorentzVector.h,v 1.12 2004/11/04 22:26:24 brun Exp $
// Author: Pasha Murat , Peter Malzacher 12/02/99
/*************************************************************************
* Copyright (C) 1995-2000, Rene Brun and Fons Rademakers. *
* All rights reserved. *
* *
* For the licensing terms see $ROOTSYS/LICENSE. *
* For the list of contributors see $ROOTSYS/README/CREDITS. *
*************************************************************************/
#ifndef ROOT_TLorentzVector
#define ROOT_TLorentzVector
//------------------------------------------------------------------------------
// Copyright(c) 1995-1997, P.Murat (CDF collaboration, FNAL)
//
// Permission to use, copy, modify and distribute this software and its
// documentation for non-commercial purposes is hereby granted without fee,
// provided that the above copyright notice appears in all copies and
// that both the copyright notice and this permission notice appear in
// the supporting documentation. The authors make no claims about the
// suitability of this software for any purpose.
// It is provided "as is" without express or implied warranty.
// *0001 Mar 29 1999 P.Murat: add forgotten scalar product (dot operator)
//------------------------------------------------------------------------------
//////////////////////////////////////////////////////////////////////////
// //
// TLorentzVector //
// //
// Place holder for real lorentz vector class. //
// //
//////////////////////////////////////////////////////////////////////////
#ifndef ROOT_TVector3
#include "TVector3.h"
#endif
#ifndef ROOT_TRotation
#include "TRotation.h"
#endif
class TLorentzRotation;
class TLorentzVector : public TObject {
private:
TVector3 fP; // 3 vector component
Double_t fE; // time or energy of (x,y,z,t) or (px,py,pz,e)
public:
enum { kX=0, kY=1, kZ=2, kT=3, kNUM_COORDINATES=4, kSIZE=kNUM_COORDINATES };
// Safe indexing of the coordinates when using with matrices, arrays, etc.
TLorentzVector(Double_t x = 0.0, Double_t y = 0.0,
Double_t z = 0.0, Double_t t = 0.0);
// Constructor giving the components x, y, z, t.
TLorentzVector(const Double_t * carray);
TLorentzVector(const Float_t * carray);
// Constructor from an array, not checked!
TLorentzVector(const TVector3 & vector3, Double_t t);
// Constructor giving a 3-Vector and a time component.
TLorentzVector(const TLorentzVector & lorentzvector);
// Copy constructor.
virtual ~TLorentzVector();
// Destructor
// inline operator TVector3 () const;
// inline operator TVector3 & ();
// Conversion (cast) to TVector3.
inline Double_t X() const;
inline Double_t Y() const;
inline Double_t Z() const;
inline Double_t T() const;
// Get position and time.
inline void SetX(Double_t a);
inline void SetY(Double_t a);
inline void SetZ(Double_t a);
inline void SetT(Double_t a);
// Set position and time.
inline Double_t Px() const;
inline Double_t Py() const;
inline Double_t Pz() const;
inline Double_t P() const;
inline Double_t E() const;
inline Double_t Energy() const;
// Get momentum and energy.
inline void SetPx(Double_t a);
inline void SetPy(Double_t a);
inline void SetPz(Double_t a);
inline void SetE(Double_t a);
// Set momentum and energy.
inline TVector3 Vect() const ;
// Get spatial component.
inline void SetVect(const TVector3 & vect3);
// Set spatial component.
inline Double_t Theta() const;
inline Double_t CosTheta() const;
inline Double_t Phi() const; //returns phi from -pi to pi
inline Double_t Rho() const;
// Get spatial vector components in spherical coordinate system.
inline void SetTheta(Double_t theta);
inline void SetPhi(Double_t phi);
inline void SetRho(Double_t rho);
// Set spatial vector components in spherical coordinate system.
inline void SetPxPyPzE(Double_t px, Double_t py, Double_t pz, Double_t e);
inline void SetXYZT(Double_t x, Double_t y, Double_t z, Double_t t);
inline void SetXYZM(Double_t x, Double_t y, Double_t z, Double_t m);
inline void SetPtEtaPhiM(Double_t pt, Double_t eta, Double_t phi, Double_t m);
inline void SetPtEtaPhiE(Double_t pt, Double_t eta, Double_t phi, Double_t e);
// Setters to provide the functionality (but a more meanigful name) of
// the previous version eg SetV4... PsetV4...
inline void GetXYZT(Double_t *carray) const;
inline void GetXYZT(Float_t *carray) const;
// Getters into an arry
// no checking!
Double_t operator () (int i) const;
inline Double_t operator [] (int i) const;
// Get components by index.
Double_t & operator () (int i);
inline Double_t & operator [] (int i);
// Set components by index.
inline TLorentzVector & operator = (const TLorentzVector &);
// Assignment.
inline TLorentzVector operator + (const TLorentzVector &) const;
inline TLorentzVector & operator += (const TLorentzVector &);
// Additions.
inline TLorentzVector operator - (const TLorentzVector &) const;
inline TLorentzVector & operator -= (const TLorentzVector &);
// Subtractions.
inline TLorentzVector operator - () const;
// Unary minus.
inline TLorentzVector operator * (Double_t a) const;
inline TLorentzVector & operator *= (Double_t a);
// Scaling with real numbers.
inline Bool_t operator == (const TLorentzVector &) const;
inline Bool_t operator != (const TLorentzVector &) const;
// Comparisons.
inline Double_t Perp2() const;
// Transverse component of the spatial vector squared.
inline Double_t Pt() const;
inline Double_t Perp() const;
// Transverse component of the spatial vector (R in cylindrical system).
inline void SetPerp(Double_t);
// Set the transverse component of the spatial vector.
inline Double_t Perp2(const TVector3 & v) const;
// Transverse component of the spatial vector w.r.t. given axis squared.
inline Double_t Pt(const TVector3 & v) const;
inline Double_t Perp(const TVector3 & v) const;
// Transverse component of the spatial vector w.r.t. given axis.
inline Double_t Et2() const;
// Transverse energy squared.
inline Double_t Et() const;
// Transverse energy.
inline Double_t Et2(const TVector3 &) const;
// Transverse energy w.r.t. given axis squared.
inline Double_t Et(const TVector3 &) const;
// Transverse energy w.r.t. given axis.
inline Double_t DeltaPhi(const TLorentzVector &) const;
inline Double_t DeltaR(const TLorentzVector &) const;
inline Double_t DrEtaPhi(const TLorentzVector &) const;
inline TVector2 EtaPhiVector();
inline Double_t Angle(const TVector3 & v) const;
// Angle wrt. another vector.
inline Double_t Mag2() const;
inline Double_t M2() const;
// Invariant mass squared.
inline Double_t Mag() const;
inline Double_t M() const;
// Invariant mass. If mag2() is negative then -sqrt(-mag2()) is returned.
inline Double_t Mt2() const;
// Transverse mass squared.
inline Double_t Mt() const;
// Transverse mass.
inline Double_t Beta() const;
inline Double_t Gamma() const;
inline Double_t Dot(const TLorentzVector &) const;
inline Double_t operator * (const TLorentzVector &) const;
// Scalar product.
inline void SetVectMag(const TVector3 & spatial, Double_t magnitude);
inline void SetVectM(const TVector3 & spatial, Double_t mass);
// Copy spatial coordinates, and set energy = sqrt(mass^2 + spatial^2)
inline Double_t Plus() const;
inline Double_t Minus() const;
// Returns t +/- z.
// Related to the positive/negative light-cone component,
// which some define this way and others define as (t +/- z)/sqrt(2)
inline TVector3 BoostVector() const ;
// Returns the spatial components divided by the time component.
void Boost(Double_t, Double_t, Double_t);
inline void Boost(const TVector3 &);
// Lorentz boost.
Double_t Rapidity() const;
// Returns the rapidity, i.e. 0.5*ln((E+pz)/(E-pz))
inline Double_t Eta() const;
inline Double_t PseudoRapidity() const;
// Returns the pseudo-rapidity, i.e. -ln(tan(theta/2))
inline void RotateX(Double_t angle);
// Rotate the spatial component around the x-axis.
inline void RotateY(Double_t angle);
// Rotate the spatial component around the y-axis.
inline void RotateZ(Double_t angle);
// Rotate the spatial component around the z-axis.
inline void RotateUz(TVector3 & newUzVector);
// Rotates the reference frame from Uz to newUz (unit vector).
inline void Rotate(Double_t, const TVector3 &);
// Rotate the spatial component around specified axis.
inline TLorentzVector & operator *= (const TRotation &);
inline TLorentzVector & Transform(const TRotation &);
// Transformation with HepRotation.
TLorentzVector & operator *= (const TLorentzRotation &);
TLorentzVector & Transform(const TLorentzRotation &);
// Transformation with HepLorenzRotation.
ClassDef(TLorentzVector,4) // A four vector with (-,-,-,+) metric
};
//inline TLorentzVector operator * (const TLorentzVector &, Double_t a);
// moved to TLorentzVector::operator * (Double_t a)
inline TLorentzVector operator * (Double_t a, const TLorentzVector &);
// Scaling LorentzVector with a real number
inline Double_t TLorentzVector::X() const { return fP.X(); }
inline Double_t TLorentzVector::Y() const { return fP.Y(); }
inline Double_t TLorentzVector::Z() const { return fP.Z(); }
inline Double_t TLorentzVector::T() const { return fE; }
inline void TLorentzVector::SetX(Double_t a) { fP.SetX(a); }
inline void TLorentzVector::SetY(Double_t a) { fP.SetY(a); }
inline void TLorentzVector::SetZ(Double_t a) { fP.SetZ(a); }
inline void TLorentzVector::SetT(Double_t a) { fE = a; }
inline Double_t TLorentzVector::Px() const { return X(); }
inline Double_t TLorentzVector::Py() const { return Y(); }
inline Double_t TLorentzVector::Pz() const { return Z(); }
inline Double_t TLorentzVector::P() const { return fP.Mag(); }
inline Double_t TLorentzVector::E() const { return T(); }
inline Double_t TLorentzVector::Energy() const { return T(); }
inline void TLorentzVector::SetPx(Double_t a) { SetX(a); }
inline void TLorentzVector::SetPy(Double_t a) { SetY(a); }
inline void TLorentzVector::SetPz(Double_t a) { SetZ(a); }
inline void TLorentzVector::SetE(Double_t a) { SetT(a); }
inline TVector3 TLorentzVector::Vect() const { return fP; }
inline void TLorentzVector::SetVect(const TVector3 &p) { fP = p; }
inline Double_t TLorentzVector::Phi() const {
return fP.Phi();
}
inline Double_t TLorentzVector::Theta() const {
return fP.Theta();
}
inline Double_t TLorentzVector::CosTheta() const {
return fP.CosTheta();
}
inline Double_t TLorentzVector::Rho() const {
return fP.Mag();
}
inline void TLorentzVector::SetTheta(Double_t th) {
fP.SetTheta(th);
}
inline void TLorentzVector::SetPhi(Double_t phi) {
fP.SetPhi(phi);
}
inline void TLorentzVector::SetRho(Double_t rho) {
fP.SetMag(rho);
}
inline void TLorentzVector::SetXYZT(Double_t x, Double_t y, Double_t z, Double_t t) {
fP.SetXYZ(x, y, z);
SetT(t);
}
inline void TLorentzVector::SetPxPyPzE(Double_t px, Double_t py, Double_t pz, Double_t e) {
SetXYZT(px, py, pz, e);
}
inline void TLorentzVector::SetXYZM(Double_t x, Double_t y, Double_t z, Double_t m) {
SetXYZT( x, y, z, TMath::Sqrt(x*x+y*y+z*z+m*m) );
}
inline void TLorentzVector::SetPtEtaPhiM(Double_t pt, Double_t eta, Double_t phi, Double_t m) {
pt = TMath::Abs(pt);
SetXYZM(pt*TMath::Cos(phi), pt*TMath::Sin(phi), pt/TMath::Tan(2.0*TMath::ATan(TMath::Exp(-eta))),m);
}
inline void TLorentzVector::SetPtEtaPhiE(Double_t pt, Double_t eta, Double_t phi, Double_t e) {
pt = TMath::Abs(pt);
SetXYZT(pt*TMath::Cos(phi), pt*TMath::Sin(phi), pt/TMath::Tan(2.0*TMath::ATan(TMath::Exp(-eta))),e);
}
inline void TLorentzVector::GetXYZT(Double_t *carray) const {
fP.GetXYZ(carray);
carray[3] = fE;
}
inline void TLorentzVector::GetXYZT(Float_t *carray) const{
fP.GetXYZ(carray);
carray[3] = fE;
}
Double_t & TLorentzVector::operator [] (int i) { return (*this)(i); }
Double_t TLorentzVector::operator [] (int i) const { return (*this)(i); }
inline TLorentzVector &
TLorentzVector::operator = (const TLorentzVector & q) {
fP = q.Vect();
fE = q.T();
return *this;
}
inline TLorentzVector
TLorentzVector::operator + (const TLorentzVector & q) const {
return TLorentzVector(fP+q.Vect(), fE+q.T());
}
inline TLorentzVector &
TLorentzVector::operator += (const TLorentzVector & q) {
fP += q.Vect();
fE += q.T();
return *this;
}
inline TLorentzVector
TLorentzVector::operator - (const TLorentzVector & q) const {
return TLorentzVector(fP-q.Vect(), fE-q.T());
}
inline TLorentzVector &
TLorentzVector::operator -= (const TLorentzVector & q) {
fP -= q.Vect();
fE -= q.T();
return *this;
}
inline TLorentzVector TLorentzVector::operator - () const {
return TLorentzVector(-X(), -Y(), -Z(), -T());
}
inline TLorentzVector& TLorentzVector::operator *= (Double_t a) {
fP *= a;
fE *= a;
return *this;
}
inline TLorentzVector TLorentzVector::operator * (Double_t a) const {
return TLorentzVector(a*X(), a*Y(), a*Z(), a*T());
}
inline Bool_t
TLorentzVector::operator == (const TLorentzVector & q) const {
return (Vect() == q.Vect() && T() == q.T());
}
inline Bool_t
TLorentzVector::operator != (const TLorentzVector & q) const {
return (Vect() != q.Vect() || T() != q.T());
}
inline Double_t TLorentzVector::Perp2() const { return fP.Perp2(); }
inline Double_t TLorentzVector::Perp() const { return fP.Perp(); }
inline Double_t TLorentzVector::Pt() const { return Perp(); }
inline void TLorentzVector::SetPerp(Double_t r) {
fP.SetPerp(r);
}
inline Double_t TLorentzVector::Perp2(const TVector3 &v) const {
return fP.Perp2(v);
}
inline Double_t TLorentzVector::Perp(const TVector3 &v) const {
return fP.Perp(v);
}
inline Double_t TLorentzVector::Pt(const TVector3 &v) const {
return Perp(v);
}
inline Double_t TLorentzVector::Et2() const {
Double_t pt2 = fP.Perp2();
return pt2 == 0 ? 0 : E()*E() * pt2/(pt2+Z()*Z());
}
inline Double_t TLorentzVector::Et() const {
Double_t etet = Et2();
return E() < 0.0 ? -sqrt(etet) : sqrt(etet);
}
inline Double_t TLorentzVector::Et2(const TVector3 & v) const {
Double_t pt2 = fP.Perp2(v);
Double_t pv = fP.Dot(v.Unit());
return pt2 == 0 ? 0 : E()*E() * pt2/(pt2+pv*pv);
}
inline Double_t TLorentzVector::Et(const TVector3 & v) const {
Double_t etet = Et2(v);
return E() < 0.0 ? -sqrt(etet) : sqrt(etet);
}
inline Double_t TLorentzVector::DeltaPhi(const TLorentzVector & v) const {
return TVector2::Phi_mpi_pi(Phi()-v.Phi());
}
inline Double_t TLorentzVector::Eta() const {
return PseudoRapidity();
}
inline Double_t TLorentzVector::DeltaR(const TLorentzVector & v) const {
Double_t deta = Eta()-v.Eta();
Double_t dphi = TVector2::Phi_mpi_pi(Phi()-v.Phi());
return TMath::Sqrt( deta*deta+dphi*dphi );
}
inline Double_t TLorentzVector::DrEtaPhi(const TLorentzVector & v) const{
return DeltaR(v);
}
inline TVector2 TLorentzVector::EtaPhiVector() {
return TVector2 (Eta(),Phi());
}
inline Double_t TLorentzVector::Angle(const TVector3 &v) const {
return fP.Angle(v);
}
inline Double_t TLorentzVector::Mag2() const {
return T()*T() - fP.Mag2();
}
inline Double_t TLorentzVector::Mag() const {
Double_t mm = Mag2();
return mm < 0.0 ? -TMath::Sqrt(-mm) : TMath::Sqrt(mm);
}
inline Double_t TLorentzVector::M2() const { return Mag2(); }
inline Double_t TLorentzVector::M() const { return Mag(); }
inline Double_t TLorentzVector::Mt2() const {
return E()*E() - Z()*Z();
}
inline Double_t TLorentzVector::Mt() const {
Double_t mm = Mt2();
return mm < 0.0 ? -TMath::Sqrt(-mm) : TMath::Sqrt(mm);
}
inline Double_t TLorentzVector::Beta() const {
return fP.Mag() / fE;
}
inline Double_t TLorentzVector::Gamma() const {
Double_t b = Beta();
return 1.0/TMath::Sqrt(1- b*b);
}
inline void
TLorentzVector::SetVectMag(const TVector3 & spatial, Double_t magnitude) {
SetVect(spatial);
SetT(TMath::Sqrt(magnitude * magnitude + spatial * spatial));
}
inline void
TLorentzVector::SetVectM(const TVector3 & spatial, Double_t mass) {
SetVectMag(spatial, mass);
}
inline Double_t TLorentzVector::Dot(const TLorentzVector & q) const {
return T()*q.T() - Z()*q.Z() - Y()*q.Y() - X()*q.X();
}
inline Double_t
TLorentzVector::operator * (const TLorentzVector & q) const {
return Dot(q);
}
//Member functions Plus() and Minus() return the positive and negative
//light-cone components:
//
// Double_t pcone = v.Plus();
// Double_t mcone = v.Minus();
//
//CAVEAT: The values returned are T{+,-}Z. It is known that some authors
//find it easier to define these components as (T{+,-}Z)/sqrt(2). Thus
//check what definition is used in the physics you're working in and adapt
//your code accordingly.
inline Double_t TLorentzVector::Plus() const {
return T() + Z();
}
inline Double_t TLorentzVector::Minus() const {
return T() - Z();
}
inline TVector3 TLorentzVector::BoostVector() const {
return TVector3(X()/T(), Y()/T(), Z()/T());
}
inline void TLorentzVector::Boost(const TVector3 & b) {
Boost(b.X(), b.Y(), b.Z());
}
inline Double_t TLorentzVector::PseudoRapidity() const {
return fP.PseudoRapidity();
}
inline void TLorentzVector::RotateX(Double_t angle) {
fP.RotateX(angle);
}
inline void TLorentzVector::RotateY(Double_t angle) {
fP.RotateY(angle);
}
inline void TLorentzVector::RotateZ(Double_t angle) {
fP.RotateZ(angle);
}
inline void TLorentzVector::RotateUz(TVector3 &newUzVector) {
fP.RotateUz(newUzVector);
}
inline void TLorentzVector::Rotate(Double_t a, const TVector3 &v) {
fP.Rotate(a,v);
}
inline TLorentzVector &
TLorentzVector::operator *= (const TRotation & m) {
fP *= m;
return *this;
}
inline TLorentzVector &
TLorentzVector::Transform(const TRotation & m) {
fP.Transform(m);
return *this;
}
inline TLorentzVector operator * (Double_t a, const TLorentzVector & p) {
return TLorentzVector(a*p.X(), a*p.Y(), a*p.Z(), a*p.T());
}
#endif
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