Rivet API documentation

Rivet 4.1.3

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.
	RIVET_DEFAULT_PROJ_CLONE (ParisiTensor)
	Clone on the heap.
void	clear ()
	Clear the projection.
virtual std::string	name () const
	Get the name of the projection.
bool	valid () const
	Get the state of the projetion.
bool	failed () const
	Get the state of the projetion.
void	markAsOwned () const
	Mark this object as owned by a proj-handler.
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
Standard constructors and destructors.
virtual unique_ptr< Projection >	clone () const =0
	Clone on the heap.
Projection operation and comparison
bool	before (const Projection &p) const
Projection "getting" functions
std::set< ConstProjectionPtr >	getProjections () const
	Get the contained projections, including recursion.
std::set< ConstProjectionPtr >	getImmediateChildProjections () const
	Get the contained projections, excluding 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
const Projection &	getProjection (const std::string &name) const
template<typename PROJ>
const PROJ &	get (const std::string &name) const
template<typename PROJ>
const PROJ &	getProjectionFromDeclQueue (const std::string name) const
Projection applying functions
template<typename PROJ = Projection>
std::enable_if_t< std::is_base_of< Projection, PROJ >::value, const PROJ & >	apply (const Event &evt, const Projection &proj) const
	Apply the supplied projection on event evt.
template<typename PROJ = Projection>
std::enable_if_t< std::is_base_of< Projection, PROJ >::value, const PROJ & >	apply (const Event &evt, const PROJ &proj) const
	Apply the supplied projection on event evt (user-facing alias).
template<typename PROJ = Projection>
std::enable_if_t< std::is_base_of< Projection, PROJ >::value, const PROJ & >	apply (const Event &evt, const std::string &name) const
	Apply the supplied projection on event evt (user-facing alias).
template<typename PROJ = Projection>
std::enable_if_t< std::is_base_of< Projection, PROJ >::value, const PROJ & >	apply (const std::string &name, const Event &evt) const
	Apply the supplied projection on event evt (convenience arg-reordering alias).

Protected Member Functions
void	project (const Event &e)
	Perform the projection on the Event.
CmpState	compare (const Projection &p) const
	Compare with other projections.
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.
void	fail ()
	Set the projection in an unvalid state.
Cmp< Projection >	mkNamedPCmp (const Projection &otherparent, const std::string &pname) const
Cmp< Projection >	mkPCmp (const Projection &otherparent, const std::string &pname) const
ProjectionHandler &	getProjHandler () const
	Get a reference to the ProjectionHandler for this thread.
void	setProjectionHandler (ProjectionHandler &projectionHandler) const
Projection registration functions
template<typename PROJ>
const PROJ &	declare (const PROJ &proj, const std::string &name) const
	Register a contained projection (user-facing version).
template<typename PROJ>
const PROJ &	declare (const std::string &name, const PROJ &proj) const
	Register a contained projection (user-facing, arg-reordered version).

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.

Member Function Documentation

◆ apply()

template<typename PROJ = Projection>

std::enable_if_t< std::is_base_of< Projection, PROJ >::value, const PROJ & > Rivet::ProjectionApplier::apply	(	const Event &	evt,
		const Projection &	proj ) const

inlineinherited

Apply the supplied projection on event evt.

Apply the supplied projection on event evt (user-facing alias).

◆ before()

bool Rivet::Projection::before ( const Projection & p ) const

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.

References Projection(), and Rivet::Kin::p().