Get the transverse spherocity scalars for hadron-colliders. More...

#include <Spherocity.hh>

Inheritance diagram for Rivet::Spherocity:

Public Member Functions
	Spherocity (const FinalState &fsp)
	Constructor.

	DEFAULT_RIVET_PROJ_CLONE (Spherocity)
	Clone on the heap.

Spherocity scalar accessors
double	spherocity () const
	The spherocity scalar, , (minimum spherocity).

Spherocity axis accessors
const Vector3 &	spherocityAxis () const
	The spherocity axis.

const Vector3 &	spherocityMajorAxis () const
	The spherocity major axis (axis of max spherocity perpendicular to spherocity axis).

const Vector3 &	spherocityMinorAxis () const
	The spherocity minor axis (axis perpendicular to spherocity and spherocity major).

AxesDefinition axis accessors.
const Vector3 &	axis1 () const

const Vector3 &	axis2 () const
	The 2nd most significant ("major") axis.

const Vector3 &	axis3 () const
	The least significant ("minor") axis.

Direct methods
Ways to do the calculation directly, without engaging the caching system
void	calc (const FinalState &fs)
	Manually calculate the spherocity, without engaging the caching system.

void	calc (const vector< Particle > &fsparticles)
	Manually calculate the spherocity, without engaging the caching system.

void	calc (const vector< FourMomentum > &fsmomenta)
	Manually calculate the spherocity, without engaging the caching system.

void	calc (const vector< Vector3 > &threeMomenta)
	Manually calculate the spherocity, without engaging the caching system.

Public Member Functions inherited from Rivet::AxesDefinition
virtual	~AxesDefinition ()
	Virtual destructor.

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

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

	Projection ()
	The default constructor.

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 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

Get the transverse spherocity scalars for hadron-colliders.

Author: Holger Schulz

The scalar (minimum) transverse spherocity is defined as

$S = \frac{\pi^2}{4} \mathrm{min}_{\vec{n}_\perp} \left( \frac{\sum_i \left|\vec{p}_{\perp,i} \times \vec{n}_\perp \right|}{\sum_i |\vec{p}_{\perp,i}|} \right)^2$

, with the direction of the unit vector $\vec{n_\perp}$ which minimises $ T $ being identified as the spherocity axis. The unit vector which maximises the spherocity scalar in the plane perpendicular to $\vec{n}$ is the "spherocity major" direction, and the vector perpendicular to both the spherocity and spherocity major directions is the spherocity minor. Both the major and minor directions have associated spherocity scalars.