Rivet  1.8.3
Public Member Functions | Protected Member Functions | List of all members
Rivet::Spherocity Class Reference

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

#include <Spherocity.hh>

Inheritance diagram for Rivet::Spherocity:
Rivet::AxesDefinition Rivet::Projection Rivet::ProjectionApplier

Public Member Functions

 Spherocity (const FinalState &fsp)
 Constructor.
 
virtual const Projectionclone () const
 Clone on the heap.
 
double spherocity () const
 
const Vector3spherocityAxis () const
 
const Vector3spherocityMajorAxis () const
 The spherocity major axis (axis of max spherocity perpendicular to spherocity axis).
 
const Vector3spherocityMinorAxis () const
 The spherocity minor axis (axis perpendicular to spherocity and spherocity major).
 
const Vector3axis1 () const
 AxesDefinition axis accessors.
 
const Vector3axis2 () const
 The 2nd most significant ("major") axis.
 
const Vector3axis3 () 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.
 
- Public Member Functions inherited from Rivet::Projection
bool before (const Projection &p) const
 
virtual const std::set< PdgIdPairbeamPairs () const
 
virtual std::string name () const
 Get the name of the projection.
 
ProjectionaddPdgIdPair (PdgId beam1, PdgId beam2)
 Add a colliding beam pair.
 
LoggetLog () 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.
 
 Projection ()
 The default constructor.
 
virtual ~Projection ()
 The destructor.
 
- Public Member Functions inherited from Rivet::ProjectionApplier
 ProjectionApplier ()
 Constructor.
 
std::set< ConstProjectionPtrgetProjections () const
 Get the contained projections, including recursion.
 
template<typename PROJ >
const PROJ & getProjection (const std::string &name) const
 Get the named projection, specifying return type via a template argument.
 
const ProjectiongetProjection (const std::string &name) const
 
template<typename PROJ >
const PROJ & applyProjection (const Event &evt, const PROJ &proj) const
 Apply the supplied projection on event.
 
template<typename PROJ >
const PROJ & applyProjection (const Event &evt, const Projection &proj) const
 Apply the supplied projection on event.
 
template<typename PROJ >
const PROJ & applyProjection (const Event &evt, const std::string &name) const
 Apply the named projection on event.
 

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
Cmp< ProjectionmkNamedPCmp (const Projection &otherparent, const std::string &pname) const
 
Cmp< ProjectionmkPCmp (const Projection &otherparent, const std::string &pname) const
 
- Protected Member Functions inherited from Rivet::ProjectionApplier
LoggetLog () const
 
ProjectionHandlergetProjHandler () const
 Get a reference to the ProjectionHandler for this thread.
 
template<typename PROJ >
const PROJ & addProjection (const PROJ &proj, const std::string &name)
 

Detailed Description

Get the transverse spherocity scalars for hadron-colliders.

Author
Holger Schulz

The scalar (maximum) transverse spherocity is defined as

\[ T = \mathrm{max}_{\vec{n_\perp}} \frac{\sum_i \left|\vec{p}_{\perp,i} \cdot \vec{n} \right|}{\sum_i |\vec{p}_{\perp,i}|} \]

, with the direction of the unit vector $ \vec{n_\perp} $ which maximises $ 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.

Care must be taken in the case of Drell-Yan processes - there we should use the newly proposed observable $ a_T $.

Member Function Documentation

double Rivet::Spherocity::spherocity ( ) const
inline

Spherocity scalar accessors The spherocity scalar, $ S $, (minimum spherocity).

const Vector3& Rivet::Spherocity::spherocityAxis ( ) const
inline

Spherocity axis accessors The spherocity axis.

Referenced by axis1().


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