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

#include <ParisiTensor.hh>

Inheritance diagram for Rivet::ParisiTensor:

Public Member Functions
	ParisiTensor (const FinalState &fsp)
	Constructor. The provided FinalState projection must live throughout the run.

	DEFAULT_RIVET_PROJ_CLONE (ParisiTensor)
	Clone on the heap.

void	clear ()
	Clear the projection.

Access the C and D params.
double	C () const

double	D () const

Access the eigenvalues of \f$\theta\f$.
double	lambda1 () const

double	lambda2 () const

double	lambda3 () const

Public Member Functions inherited from Rivet::Projection
virtual std::string	name () const
	Get the name of the projection.

	Projection ()
	The default constructor.

virtual unique_ptr< Projection >	clone () const =0
	Clone on the heap.

virtual	~Projection ()
	The destructor.

bool	before (const Projection &p) const

virtual const std::set< PdgIdPair >	beamPairs () const

Projection &	addPdgIdPair (PdgId beam1, PdgId beam2)

Public Member Functions inherited from Rivet::ProjectionApplier
	ProjectionApplier ()
	Constructor.

void	markAsOwned () const
	Mark this object as owned by a proj-handler.

std::set< ConstProjectionPtr >	getProjections () const
	Get the contained projections, including recursion.

bool	hasProjection (const std::string &name) const
	Does this applier have a projection registered under the name name?

template<typename PROJ >
const PROJ &	getProjection (const std::string &name) const

template<typename PROJ >
const PROJ &	get (const std::string &name) const

const Projection &	getProjection (const std::string &name) const

template<typename PROJ >
const PROJ &	applyProjection (const Event &evt, const Projection &proj) const
	Apply the supplied projection on event evt. More...

template<typename PROJ >
const PROJ &	apply (const Event &evt, const Projection &proj) const

template<typename PROJ >
const PROJ &	applyProjection (const Event &evt, const PROJ &proj) const
	Apply the supplied projection on event evt. More...

template<typename PROJ >
const PROJ &	apply (const Event &evt, const PROJ &proj) const

template<typename PROJ >
const PROJ &	applyProjection (const Event &evt, const std::string &name) const

template<typename PROJ >
const PROJ &	apply (const Event &evt, const std::string &name) const

template<typename PROJ >
const PROJ &	apply (const std::string &name, const Event &evt) 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.

Protected Member Functions inherited from Rivet::Projection
Log &	getLog () const
	Get a Log object based on the getName() property of the calling projection object.

void	setName (const std::string &name)
	Used by derived classes to set their name.

Cmp< Projection >	mkNamedPCmp (const Projection &otherparent, const std::string &pname) const

Cmp< Projection >	mkPCmp (const Projection &otherparent, const std::string &pname) const

virtual Projection &	operator= (const Projection &)
	Block Projection copying.

Protected Member Functions inherited from Rivet::ProjectionApplier
Log &	getLog () const

ProjectionHandler &	getProjHandler () const
	Get a reference to the ProjectionHandler for this thread.

template<typename PROJ >
const PROJ &	declareProjection (const PROJ &proj, const std::string &name)
	Register a contained projection. More...

template<typename PROJ >
const PROJ &	declare (const PROJ &proj, const std::string &name)
	Register a contained projection (user-facing version) More...

template<typename PROJ >
const PROJ &	declare (const std::string &name, const PROJ &proj)
	Register a contained projection (user-facing, arg-reordered version) More...

template<typename PROJ >
const PROJ &	addProjection (const PROJ &proj, const std::string &name)
	Register a contained projection (user-facing version) More...

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.

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

include/Rivet/Projections/ParisiTensor.hh
src/Projections/ParisiTensor.cc

Public Member Functions

Protected Member Functions

Detailed Description