Rivet::Thrust Class Referenceabstract Get the e+ e- thrust basis and the thrust, thrust major and thrust minor scalars. More...
Inheritance diagram for Rivet::Thrust:
Detailed DescriptionGet the e+ e- thrust basis and the thrust, thrust major and thrust minor scalars. The scalar (maximum) thrust is defined as \[ T = \mathrm{max}_{\vec{n}} \frac{\sum_i \left|\vec{p}_i \cdot \vec{n} \right|}{\sum_i |\vec{p}_i|} \] , with the direction of the unit vector \( \vec{n} \) which maximises \( T \) being identified as the thrust axis. The unit vector which maximises the thrust scalar in the plane perpendicular to \( \vec{n} \) is the "thrust major" direction, and the vector perpendicular to both the thrust and thrust major directions is the thrust minor. Both the major and minor directions have associated thrust scalars. Thrust calculations have particularly simple forms for less than 4 particles, and in those cases this projection is computationally minimal. For 4 or more particles, a more general calculation must be carried out, based on the Brandt/Dahmen method from Z. Phys. C1 (1978). While a polynomial improvement on the exponential scaling of the naive method, this algorithm scales asymptotically as \( \mathcal{O}\left( n^3 \right) \). Be aware that the thrust may easily be the most computationally demanding projection in Rivet for large events! The Rivet implementation of thrust is based heavily on Stefan Gieseke's Herwig++ re-coding of the 'tasso' code from HERWIG. NB. special case with >= 4 coplanar particles will still fail. NB. Thrust assumes all momenta are in the CoM system: no explicit boost is performed. This can be dealt with by appropriate choice of the supplied FinalState. Member Function Documentation◆ addPdgIdPair()
Add a colliding beam pair.
◆ applyProjection() [1/3]
template<typename PROJ = Projection>
Apply the supplied projection on event evt.
◆ applyProjection() [2/3]
template<typename PROJ = Projection>
Apply the supplied projection on event evt.
◆ applyProjection() [3/3]
template<typename PROJ = Projection>
Apply the named projection on event evt.
References Rivet::ProjectionApplier::name(). ◆ axis1()
◆ axis2()
The 2nd most significant ("major") axis. Implements Rivet::AxesDefinition. References thrustMajorAxis(). ◆ axis3()
The least significant ("minor") axis. Implements Rivet::AxesDefinition. References thrustMinorAxis(). ◆ beamPairs()
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.
◆ before()
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. ◆ clone()
Clone on the heap. Implements Rivet::Projection. ◆ compare()
Compare projections. Implements Rivet::Projection. References Rivet::Projection::mkNamedPCmp(), and Rivet::Kin::p(). ◆ declare() [1/2]
template<typename PROJ >
Register a contained projection (user-facing version)
References Rivet::ProjectionApplier::declareProjection(), and Rivet::ProjectionApplier::name(). Referenced by 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::GammaGammaFinalState::GammaGammaFinalState(), 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< FILTER >::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::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::TriggerCDFRun0Run1::TriggerCDFRun0Run1(), Rivet::TriggerCDFRun2::TriggerCDFRun2(), Rivet::UndressBeamLeptons::UndressBeamLeptons(), Rivet::ALICE::V0AndTrigger::V0AndTrigger(), Rivet::ALICE::V0Trigger< MODE >::V0Trigger(), Rivet::VetoedFinalState::VetoedFinalState(), Rivet::VisibleFinalState::VisibleFinalState(), Rivet::CentralityProjection::add(), Rivet::VetoedFinalState::addVetoOnThisFinalState(), and Rivet::CentralityBinner< T, MDist >::setProjection(). ◆ declare() [2/2]
template<typename PROJ >
Register a contained projection (user-facing, arg-reordered version)
References Rivet::ProjectionApplier::declareProjection(), and Rivet::ProjectionApplier::name(). ◆ declareProjection()
template<typename PROJ >
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
References Rivet::ProjectionApplier::name(). Referenced by Rivet::ProjectionApplier::declare(). ◆ get()
template<typename PROJ >
Get the named projection, specifying return type via a template argument (user-facing alias).
References Rivet::ProjectionApplier::name(). ◆ getProjection() [1/2]
template<typename PROJ >
Get the named projection, specifying return type via a template argument.
References Rivet::ProjectionHandler::getProjection(), Rivet::ProjectionApplier::getProjHandler(), Rivet::ProjectionApplier::name(), and Rivet::Kin::p(). Referenced by Rivet::CentralityProjection::compare(), and Rivet::pcmp(). ◆ getProjection() [2/2]
Get the named projection (non-templated, so returns as a reference to a Projection base class). References Rivet::ProjectionHandler::getProjection(), Rivet::ProjectionApplier::getProjHandler(), and Rivet::ProjectionApplier::name(). ◆ mkNamedPCmp()
Shortcut to make a named Cmp<Projection> comparison with the Referenced by Rivet::MC_SumETFwdPbCentrality::compare(), Rivet::MC_pPbMinBiasTrigger::compare(), Rivet::BeamThrust::compare(), Rivet::CentralEtHCM::compare(), Rivet::DISFinalState::compare(), Rivet::EventMixingBase::compare(), Rivet::FParameter::compare(), Rivet::GammaGammaFinalState::compare(), Rivet::HeavyHadrons::compare(), Rivet::Hemispheres::compare(), Rivet::LossyFinalState< FILTER >::compare(), Rivet::PercentileProjection::compare(), Rivet::Spherocity::compare(), compare(), Rivet::ATLAS::SumET_PB_Centrality::compare(), Rivet::ATLAS::SumET_PBPB_Centrality::compare(), Rivet::ATLAS::MinBiasTrigger::compare(), Rivet::CentralityEstimator::compare(), Rivet::GeneratedCentrality::compare(), Rivet::STAR_BES_Centrality::compare(), and Rivet::BRAHMSCentrality::compare(). ◆ mkPCmp()
Shortcut to make a named Cmp<Projection> comparison with the
Referenced by Rivet::ALICE::PrimaryParticles::compare(), Rivet::SmearedJets::compare(), Rivet::SmearedMET::compare(), Rivet::SmearedParticles::compare(), and Rivet::Correlators::compare(). ◆ name()
Get the name of the projection. Implements Rivet::ProjectionApplier. Referenced by Rivet::VetoedFinalState::addVetoOnThisFinalState(), Rivet::Projection::getLog(), and Rivet::Projection::setName(). ◆ project()
◆ thrust()
Thrust scalar accessors The thrust scalar, \( T \), (maximum thrust). ◆ thrustAxis()
The documentation for this class was generated from the following file:
Generated on Fri May 13 2022 23:02:06 for Rivet by  1.9.4
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