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Rivet
3.1.2
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Calculate the sphericity event shape. More...
#include <Sphericity.hh>
Public Member Functions | |
void | clear () |
Reset the projection. | |
Vector3 | mkEigenVector (Matrix3 A, const double &lambda) |
virtual unique_ptr< Projection > | clone () const =0 |
Clone on the heap. | |
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. | |
Constructors etc. | |
Sphericity (double rparam=2.0) | |
Constructor. | |
Sphericity (const FinalState &fsp, double rparam=2.0) | |
DEFAULT_RIVET_PROJ_CLONE (Sphericity) | |
Clone on the heap. | |
Access the event shapes by name | |
double | sphericity () const |
Sphericity. | |
double | transSphericity () const |
Transverse sphericity. | |
double | planarity () const |
Planarity. | |
double | aplanarity () const |
Aplanarity. | |
Access the sphericity basis vectors | |
const Vector3 & | sphericityAxis () const |
Sphericity axis. | |
const Vector3 & | sphericityMajorAxis () const |
Sphericity major axis. | |
const Vector3 & | sphericityMinorAxis () const |
Sphericity minor axis. | |
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. | |
Access the momentum tensor eigenvalues | |
double | lambda1 () const |
double | lambda2 () const |
double | lambda3 () const |
Direct methods | |
Ways to do the calculation directly, without engaging the caching system | |
void | calc (const FinalState &fs) |
Manually calculate the sphericity, without engaging the caching system. | |
void | calc (const Particles &particles) |
Manually calculate the sphericity, without engaging the caching system. | |
void | calc (const Jets &jets) |
Manually calculate the sphericity, without engaging the caching system. | |
void | calc (const vector< FourMomentum > &momenta) |
Manually calculate the sphericity, without engaging the caching system. | |
void | calc (const vector< Vector3 > &momenta) |
Manually calculate the sphericity, without engaging the caching system. More... | |
Projection operation and comparison | |
bool | before (const Projection &p) const |
Beam configuration | |
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virtual const std::set< PdgIdPair > | beamPairs () const |
Projection & | addPdgIdPair (PdgId beam1, PdgId beam2) |
Projection "getting" functions | |
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 |
const Projection & | getProjection (const std::string &name) const |
template<typename PROJ > | |
const PROJ & | get (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 & > | applyProjection (const Event &evt, const Projection &proj) const |
template<typename PROJ = Projection> | |
std::enable_if_t< std::is_base_of< Projection, PROJ >::value, const PROJ & > | applyProjection (const Event &evt, const PROJ &proj) const |
template<typename PROJ = Projection> | |
std::enable_if_t< std::is_base_of< Projection, PROJ >::value, const PROJ & > | applyProjection (const Event &evt, const std::string &name) const |
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 (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 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. | |
Projection registration functions | |
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... | |
Calculate the sphericity event shape.
The sphericity tensor (or quadratic momentum tensor) is defined as
\[ S^{\alpha \beta} = \frac{\sum_i p_i^\alpha p_i^\beta}{\sum_i |\mathbf{p}_i|^2} \]
, where the Greek indices are spatial components and the Latin indices are used for sums over particles. From this, the sphericity, aplanarity and planarity can be calculated by combinations of eigenvalues.
Defining the three eigenvalues \( \lambda_1 \ge \lambda_2 \ge \lambda_3 \), with \( \lambda_1 + \lambda_2 + \lambda_3 = 1 \), the sphericity is
\[ S = \frac{3}{2} (\lambda_2 + \lambda_3) \]
The aplanarity is \( A = \frac{3}{2}\lambda_3 \) and the planarity is \( P = \frac{2}{3}(S-2A) = \lambda_2 - \lambda_3 \). The eigenvectors define a set of spatial axes comparable with the thrust axes, but more sensitive to high momentum particles due to the quadratic sensitivity of the tensor to the particle momenta.
Since the sphericity is quadratic in the particle momenta, it is not an infrared safe observable in perturbative QCD. This can be fixed by adding a regularizing power of \(r\) to the definition:
\[ S^{\alpha \beta} = \frac{\sum_i |\mathbf{p}_i|^{r-2} p_i^\alpha p_i^\beta} {\sum_i |\mathbf{p}_i|^r} \]
\(r\) is available as a constructor argument on this class and will be taken into account by the Cmp<Projection> operation, so a single analysis can use several sphericity projections with different \(r\) values without fear of a clash.
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inlineinherited |
Add a colliding beam pair.
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inlineinherited |
Apply the supplied projection on event evt.
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inlineinherited |
Apply the supplied projection on event evt.
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inlineinherited |
Apply the named projection on event evt.
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inlinevirtual |
Axis accessors, in decreasing order of significance. The main axis.
Implements Rivet::AxesDefinition.
References sphericityAxis().
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virtualinherited |
Return the allowed beam pairs on which this projection can operate, not including recursion. Derived classes should ensure that all contained projections are registered in the _projections set for the beam constraint chaining to work.
Referenced by Rivet::Projection::failed().
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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.
Referenced by Rivet::Projection::fail(), and Rivet::Projection::failed().
void Rivet::Sphericity::calc | ( | const vector< Vector3 > & | momenta | ) |
Manually calculate the sphericity, without engaging the caching system.
This one actually does the calculation
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inlineprotectedinherited |
Register a contained projection (user-facing version)
References Rivet::ProjectionApplier::declareProjection().
Referenced by Rivet::CentralityProjection::add(), Rivet::VetoedFinalState::addVetoOnThisFinalState(), Rivet::BeamThrust::BeamThrust(), Rivet::CentralEtHCM::CentralEtHCM(), Rivet::CentralityEstimator::CentralityEstimator(), Rivet::ChargedLeptons::ChargedLeptons(), Rivet::ALICE::CLMultiplicity< INNER >::CLMultiplicity(), Rivet::DISDiffHadron::DISDiffHadron(), Rivet::DISFinalState::DISFinalState(), Rivet::DISKinematics::DISKinematics(), Rivet::DISLepton::DISLepton(), Rivet::GammaGammaKinematics::GammaGammaKinematics(), Rivet::GammaGammaLeptons::GammaGammaLeptons(), Rivet::GeneratedCentrality::GeneratedCentrality(), Rivet::HadronicFinalState::HadronicFinalState(), Rivet::HeavyHadrons::HeavyHadrons(), Rivet::Hemispheres::Hemispheres(), Rivet::InvisibleFinalState::InvisibleFinalState(), Rivet::LeadingParticlesFinalState::LeadingParticlesFinalState(), Rivet::LossyFinalState< ConstRandomFilter >::LossyFinalState(), Rivet::MC_pPbMinBiasTrigger::MC_pPbMinBiasTrigger(), Rivet::MC_SumETFwdPbCentrality::MC_SumETFwdPbCentrality(), Rivet::ATLAS::MinBiasTrigger::MinBiasTrigger(), Rivet::MissingMomentum::MissingMomentum(), Rivet::NeutralFinalState::NeutralFinalState(), Rivet::NonHadronicFinalState::NonHadronicFinalState(), Rivet::ParisiTensor::ParisiTensor(), Rivet::PercentileProjection::PercentileProjection(), Rivet::PrimaryHadrons::PrimaryHadrons(), Rivet::CentralityBinner< T, MDist >::setProjection(), Rivet::SmearedJets::SmearedJets(), Rivet::SmearedMET::SmearedMET(), Rivet::SmearedParticles::SmearedParticles(), Rivet::Spherocity::Spherocity(), Rivet::ATLAS::SumET_PB_Centrality::SumET_PB_Centrality(), Rivet::ATLAS::SumET_PBPB_Centrality::SumET_PBPB_Centrality(), Rivet::TauFinder::TauFinder(), Rivet::Thrust::Thrust(), Rivet::TriggerCDFRun0Run1::TriggerCDFRun0Run1(), Rivet::TriggerCDFRun2::TriggerCDFRun2(), Rivet::UndressBeamLeptons::UndressBeamLeptons(), Rivet::ALICE::V0AndTrigger::V0AndTrigger(), Rivet::ALICE::V0Trigger< MODE >::V0Trigger(), Rivet::VetoedFinalState::VetoedFinalState(), and Rivet::VisibleFinalState::VisibleFinalState().
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inlineprotectedinherited |
Register a contained projection (user-facing, arg-reordered version)
References Rivet::ProjectionApplier::declareProjection(), and Rivet::ProjectionApplier::name().
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inlineprotectedinherited |
Register a contained projection.
The type of the argument is used to instantiate a new projection internally: this new object is applied to events rather than the argument object. Hence you are advised to only use locally-scoped Projection objects in your Projection and Analysis constructors, and to avoid polymorphism (e.g. handling ConcreteProjection
via a pointer or reference to type Projection
) since this will screw up the internal type management.
Referenced by Rivet::ProjectionApplier::declare().
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inlineinherited |
Get the named projection, specifying return type via a template argument (user-facing alias).
References Rivet::ProjectionApplier::name().
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inlineinherited |
Get the named projection, specifying return type via a template argument.
References Rivet::ProjectionHandler::getProjection(), and Rivet::ProjectionApplier::getProjHandler().
Referenced by Rivet::pcmp().
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inlineinherited |
Get the named projection (non-templated, so returns as a reference to a Projection base class).
References Rivet::ProjectionHandler::getProjection(), and Rivet::ProjectionApplier::getProjHandler().
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protectedinherited |
Shortcut to make a named Cmp<Projection> comparison with the *this
object automatically passed as one of the parent projections.
Referenced by Rivet::FParameter::compare(), Rivet::STAR_BES_Centrality::compare(), Rivet::CentralEtHCM::compare(), Rivet::BeamThrust::compare(), Rivet::MC_SumETFwdPbCentrality::compare(), Rivet::ATLAS::SumET_PB_Centrality::compare(), Rivet::CentralityEstimator::compare(), Rivet::Spherocity::compare(), Rivet::GammaGammaFinalState::compare(), Rivet::LossyFinalState< ConstRandomFilter >::compare(), Rivet::BRAHMSCentrality::compare(), Rivet::Thrust::compare(), Rivet::DISFinalState::compare(), Rivet::MC_pPbMinBiasTrigger::compare(), Rivet::ATLAS::SumET_PBPB_Centrality::compare(), Rivet::Hemispheres::compare(), Rivet::HeavyHadrons::compare(), Rivet::PercentileProjection::compare(), Rivet::ATLAS::MinBiasTrigger::compare(), Rivet::EventMixingBase::compare(), Rivet::GeneratedCentrality::compare(), and Rivet::Projection::fail().
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protectedinherited |
Shortcut to make a named Cmp<Projection> comparison with the *this
object automatically passed as one of the parent projections.
Referenced by Rivet::SmearedMET::compare(), Rivet::SmearedParticles::compare(), Rivet::SmearedJets::compare(), Rivet::Correlators::compare(), Rivet::ALICE::PrimaryParticles::compare(), and Rivet::Projection::fail().