Skip to content

Implement rapidity-based DeltaR calculations in TLorentzVector #7087

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
lmoneta merged 4 commits into from
Feb 5, 2021
Merged

Implement rapidity-based DeltaR calculations in TLorentzVector #7087

Show file tree
Hide file tree
Changes from 2 commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
eb0e38e
Implement rapidity-based DeltaR calculations in TLorentzVector
mattleblanc Jan 22, 2021
6436285
Implement rapidity-based DeltaR calculation option in GenVector
mattleblanc Jan 26, 2021
b3c92e7
Implement separate DeltaRapidityPhi function for VectorUtil
mattleblanc Feb 2, 2021
e13f3f1
Fixing whitespace in VectorUtil.h
mattleblanc Feb 2, 2021
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
30 changes: 27 additions & 3 deletions math/genvector/inc/Math/GenVector/VectorUtil.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -83,17 +83,41 @@ namespace ROOT {
return dphi*dphi + deta*deta;
}

/**
Find square of the difference in true rapidity (y) and Phi betwen two generic vectors
The only requirements on the Vector classes is that they implement the Phi() and Rapidity() method
\param v1 Vector 1
\param v2 Vector 2
\return Angle between the two vectors
\f[ \Delta R2 = ( \Delta \phi )^2 + ( \Delta \y )^2 \f],
*/
template <class Vector1, class Vector2>
inline typename Vector1::Scalar DeltaR2RapidityPhi( const Vector1 & v1, const Vector2 & v2) {
typename Vector1::Scalar dphi = DeltaPhi(v1,v2);
typename Vector1::Scalar drap = v2.Rapidity() - v1.Rapidity();
return dphi*dphi + drap*drap;
}

/**
Find difference in pseudorapidity (Eta) and Phi betwen two generic vectors
The only requirements on the Vector classes is that they implement the Phi() and Eta() method
An option to use the rapidity instead of Eta is included, for use with massive vectors.
\param v1 Vector 1
\param v2 Vector 2
\param useRapidity use rapidity instead of pseudorapidity?
\return Angle between the two vectors
\f[ \Delta R = \sqrt{ ( \Delta \phi )^2 + ( \Delta \eta )^2 } \f]
\f[ \Delta R = \sqrt{ ( \Delta \phi )^2 + ( \Delta \eta )^2 } \f],
or
\f[ \Delta R2 = ( \Delta \phi )^2 + ( \Delta \y )^2 \f]
if useRapidity is true.
*/
template <class Vector1, class Vector2>
inline typename Vector1::Scalar DeltaR( const Vector1 & v1, const Vector2 & v2) {
return std::sqrt( DeltaR2(v1,v2) );
inline typename Vector1::Scalar DeltaR( const Vector1 & v1, const Vector2 & v2, const bool useRapidity=false) {
if(useRapidity==false){
return std::sqrt( DeltaR2(v1,v2) );
} else {
return std::sqrt( DeltaR2RapidityPhi(v1,v2) );
}
}


Expand Down
22 changes: 17 additions & 5 deletions math/physics/inc/TLorentzVector.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -181,8 +181,9 @@ class TLorentzVector : public TObject {
// Transverse energy w.r.t. given axis.

inline Double_t DeltaPhi(const TLorentzVector &) const;
inline Double_t DeltaR(const TLorentzVector &) const;
inline Double_t DeltaR(const TLorentzVector &, Bool_t useRapidity=kFALSE) const;
inline Double_t DrEtaPhi(const TLorentzVector &) const;
inline Double_t DrRapidityPhi(const TLorentzVector &) const;
inline TVector2 EtaPhiVector();

inline Double_t Angle(const TVector3 & v) const;
Expand Down Expand Up @@ -460,16 +461,27 @@ inline Double_t TLorentzVector::DeltaPhi(const TLorentzVector & v) const {
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::DeltaR(const TLorentzVector & v, const Bool_t useRapidity) const {
if(useRapidity){
Double_t drap = Rapidity()-v.Rapidity();
Double_t dphi = TVector2::Phi_mpi_pi(Phi()-v.Phi());
return TMath::Sqrt( drap*drap+dphi*dphi );
} else {
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 Double_t TLorentzVector::DrRapidityPhi(const TLorentzVector & v) const{
return DeltaR(v, kTRUE);
}

inline TVector2 TLorentzVector::EtaPhiVector() {
return TVector2 (Eta(),Phi());
}
Expand Down