Main Page | Namespace List | Class Hierarchy | Class List | Directories | File List | Namespace Members | Class Members | File Members | Related Pages

ParisiTensor Class Reference

#include <ParisiTensor.hh>

Inheritance diagram for ParisiTensor:

Inheritance graph
[legend]
Collaboration diagram for ParisiTensor:

Collaboration graph
[legend]
List of all members.

Detailed Description

Calculate the Parisi event shape tensor (or linear momentum tensor).

The Parisi event shape C and D variables are derived from the eigenvalues of the linear momentum tensor

\[ \theta^{\alpha \beta} = \frac{\sum_i \frac{p_i^\alpha p_i^\beta}{|\mathbf{p}_i|}} {\sum_i |\mathbf{p}_i|} \]

which is actually a linearized (and hence infra-red safe) version of the Sphericity tensor.

Defining the three eigenvalues of $\theta$ $ \lambda_1 \ge \lambda_2 \ge \lambda_3 $, with $ \lambda_1 + \lambda_2 + \lambda_3 = 1 $, the C and D parameters are defined as

\[ C = 3(\lambda_1\lambda_2 + \lambda_1\lambda_3 + \lambda_2\lambda_3) \]

and

\[ D = 27 \lambda_1\lambda_2\lambda_3 \]

Internally, this Projection uses the Sphericity projection with the generalising $r$ parameter set to 1.

Definition at line 40 of file ParisiTensor.hh.


Public Member Functions

 ParisiTensor (FinalState &fsp)
 Constructor. The provided FinalState projection must live throughout the run.
string getName () const
 Return the name of the projection.
bool before (const Projection &p) const
virtual const Cuts getCuts () const
virtual const set< BeamPair > getBeamPairs () const
set< Projection * > getProjections () const
 Get the contained projections, including recursion.
Access the C and D params.
const double C () const
const double D () const
Access the eigenvalues of \f$\theta\f$.
const double lambda1 () const
const double lambda2 () const
const double lambda3 () const

Protected Member Functions

void project (const Event &e)
 Perform the projection on the Event.
int compare (const Projection &p) const
 Compare with other projections.
Projection & addProjection (Projection &proj)
 Add a projection dependency to the projection list.
Projection & addBeamPair (const ParticleName &beam1, const ParticleName &beam2)
 Add a colliding beam pair.
Projection & addCut (const string &quantity, const Comparison &comparison, const double value)
 Add a cut.
Log & getLog ()
 Get a Log object based on the getName() property of the calling projection object.

Protected Attributes

Cuts _cuts
 Parameter constraints.
set< BeamPair > _beamPairs
 Beam-type constraint.
set< Projection * > _projections
 Collection of pointers to projections, for automatically combining constraints.

Friends

class Event
 Event is a friend.
class Cmp<Projection>
 The Cmp specialization for Projection is a friend.

Constructor & Destructor Documentation

ParisiTensor (  FinalState &  fsp  )  [inline]
 

Constructor. The provided FinalState projection must live throughout the run.

Definition at line 45 of file ParisiTensor.hh.

Member Function Documentation

Projection& addBeamPair (  const ParticleName &  beam1,
const ParticleName &  beam2
)  [inline, protected, inherited]
 

Add a colliding beam pair.

Definition at line 145 of file Projection.hh.

References Rivet::BeamPair.

Projection& addCut (  const string &  quantity,
const Comparison &  comparison,
const double  value
)  [inline, protected, inherited]
 

Add a cut.

Definition at line 151 of file Projection.hh.

Projection& addProjection (  Projection &  proj  )  [inline, protected, inherited]
 

Add a projection dependency to the projection list.

Definition at line 139 of file Projection.hh.

bool before (  const Projection &  p  )  const [inline, inherited]
 

Determine whether this object should be ordered before the object p given as argument. If p is of a different class than this, the before() function of the corresponding type_info objects is used. Otherwise, if the objects are of the same class, the virtual compare(const Projection &) will be returned.

Definition at line 88 of file Projection.hh.

Referenced by less< const Rivet::Projection * >::operator()().

const double C (   )  const [inline]
 

Definition at line 69 of file ParisiTensor.hh.

Referenced by ZPhys73C11::analyze().

int compare (  const Projection &  p  )  const [protected, virtual]
 

Compare with other projections.

Implements Projection.

Definition at line 11 of file ParisiTensor.cc.

References ParisiTensor::_sphproj, and Rivet::pcmp().

const double D (   )  const [inline]
 

Definition at line 70 of file ParisiTensor.hh.

Referenced by ZPhys73C11::analyze().

virtual const set<BeamPair> getBeamPairs (   )  const [inline, virtual, inherited]
 

Return the BeamConstraints for this projection. Derived classes should ensure that all contained projections are registered in the _projections set for the beam constraint chaining to work.

Definition at line 114 of file Projection.hh.

References Cuts::end(), and Rivet::intersection().

virtual const Cuts getCuts (   )  const [inline, virtual, inherited]
 

Return the Cuts objects for this projection. Derived classes should ensure that all contained projections are registered in the _projections set for the cut chaining to work.

Definition at line 102 of file Projection.hh.

References Cuts::addCuts().

Log & getLog (   )  [protected, inherited]
 

Get a Log object based on the getName() property of the calling projection object.

Definition at line 7 of file Projection.cc.

References Log::getLog(), and Projection::getName().

Referenced by VetoedFinalState::project(), TrackJet::project(), TotalVisibleMomentum::project(), Sphericity::project(), Multiplicity::project(), ChargedLeptons::project(), ChargedFinalState::project(), and Beam::project().

string getName (   )  const [inline, virtual]
 

Return the name of the projection.

Reimplemented from Projection.

Definition at line 53 of file ParisiTensor.hh.

set<Projection*> getProjections (   )  const [inline, inherited]
 

Get the contained projections, including recursion.

Definition at line 128 of file Projection.hh.

References Cuts::end().

const double lambda1 (   )  const [inline]
 

Definition at line 75 of file ParisiTensor.hh.

Referenced by ParisiTensor::project().

const double lambda2 (   )  const [inline]
 

Definition at line 76 of file ParisiTensor.hh.

Referenced by ParisiTensor::project().

const double lambda3 (   )  const [inline]
 

Definition at line 77 of file ParisiTensor.hh.

Referenced by ParisiTensor::project().

void project (  const Event &  e  )  [protected, virtual]
 

Perform the projection on the Event.

Implements Projection.

Definition at line 23 of file ParisiTensor.cc.

References Event::applyProjection(), ParisiTensor::lambda1(), Sphericity::lambda1(), ParisiTensor::lambda2(), Sphericity::lambda2(), ParisiTensor::lambda3(), and Sphericity::lambda3().

Friends And Related Function Documentation

friend class Cmp<Projection> [friend, inherited]
 

The Cmp specialization for Projection is a friend.

Definition at line 31 of file Projection.hh.

friend class Event [friend, inherited]
 

Event is a friend.

Definition at line 28 of file Projection.hh.

Member Data Documentation

set<BeamPair> _beamPairs [protected, inherited]
 

Beam-type constraint.

Definition at line 164 of file Projection.hh.

Cuts _cuts [protected, inherited]
 

Parameter constraints.

Definition at line 161 of file Projection.hh.

set<Projection*> _projections [protected, inherited]
 

Collection of pointers to projections, for automatically combining constraints.

Definition at line 167 of file Projection.hh.

The documentation for this class was generated from the following files: