|
| | JetFlavourClustering (const edm::ParameterSet &) |
| |
| | ~JetFlavourClustering () |
| |
| | EDProducer ()=default |
| |
| | EDProducerBase () |
| |
| ModuleDescription const & | moduleDescription () const |
| |
| virtual | ~EDProducerBase () |
| |
| void | callWhenNewProductsRegistered (std::function< void(BranchDescription const &)> const &func) |
| |
| | ProducerBase () |
| |
| void | registerProducts (ProducerBase *, ProductRegistry *, ModuleDescription const &) |
| |
std::function< void(BranchDescription
const &)> | registrationCallback () const |
| | used by the fwk to register list of products More...
|
| |
| virtual | ~ProducerBase () |
| |
| std::vector< ConsumesInfo > | consumesInfo () const |
| |
| | EDConsumerBase () |
| |
| ProductHolderIndexAndSkipBit | indexFrom (EDGetToken, BranchType, TypeID const &) const |
| |
| void | itemsMayGet (BranchType, std::vector< ProductHolderIndexAndSkipBit > &) const |
| |
| void | itemsToGet (BranchType, std::vector< ProductHolderIndexAndSkipBit > &) const |
| |
std::vector
< ProductHolderIndexAndSkipBit >
const & | itemsToGetFromEvent () const |
| |
| void | labelsForToken (EDGetToken iToken, Labels &oLabels) const |
| |
| void | modulesDependentUpon (std::string const &iProcessName, std::string const &iModuleLabel, bool iPrint, std::vector< char const * > &oModuleLabels) const |
| |
| void | modulesWhoseProductsAreConsumed (std::vector< ModuleDescription const * > &modules, ProductRegistry const &preg, std::map< std::string, ModuleDescription const * > const &labelsToDesc, std::string const &processName) const |
| |
| bool | registeredToConsume (ProductHolderIndex, bool, BranchType) const |
| |
| bool | registeredToConsumeMany (TypeID const &, BranchType) const |
| |
| void | updateLookup (BranchType iBranchType, ProductHolderIndexHelper const &) |
| |
| virtual | ~EDConsumerBase () |
| |
|
| typedef CacheContexts< T...> | CacheTypes |
| |
| typedef CacheTypes::GlobalCache | GlobalCache |
| |
| typedef AbilityChecker< T...> | HasAbility |
| |
typedef
CacheTypes::LuminosityBlockCache | LuminosityBlockCache |
| |
typedef
LuminosityBlockContextT
< LuminosityBlockCache,
RunCache, GlobalCache > | LuminosityBlockContext |
| |
typedef
CacheTypes::LuminosityBlockSummaryCache | LuminosityBlockSummaryCache |
| |
| typedef CacheTypes::RunCache | RunCache |
| |
typedef RunContextT< RunCache,
GlobalCache > | RunContext |
| |
| typedef CacheTypes::RunSummaryCache | RunSummaryCache |
| |
| typedef EDProducerAdaptorBase | ModuleType |
| |
typedef
ProductRegistryHelper::TypeLabelList | TypeLabelList |
| |
| typedef ProductLabels | Labels |
| |
| template<typename ProductType , BranchType B = InEvent> |
| EDGetTokenT< ProductType > | consumes (edm::InputTag const &tag) |
| |
| EDGetToken | consumes (const TypeToGet &id, edm::InputTag const &tag) |
| |
| template<BranchType B> |
| EDGetToken | consumes (TypeToGet const &id, edm::InputTag const &tag) |
| |
| ConsumesCollector | consumesCollector () |
| | Use a ConsumesCollector to gather consumes information from helper functions. More...
|
| |
| template<typename ProductType , BranchType B = InEvent> |
| void | consumesMany () |
| |
| void | consumesMany (const TypeToGet &id) |
| |
| template<BranchType B> |
| void | consumesMany (const TypeToGet &id) |
| |
| template<typename ProductType , BranchType B = InEvent> |
| EDGetTokenT< ProductType > | mayConsume (edm::InputTag const &tag) |
| |
| EDGetToken | mayConsume (const TypeToGet &id, edm::InputTag const &tag) |
| |
| template<BranchType B> |
| EDGetToken | mayConsume (const TypeToGet &id, edm::InputTag const &tag) |
| |
Clusters hadrons, partons, and jet contituents to determine the jet flavour.
This producer clusters hadrons, partons and jet contituents to determine the jet flavour. The jet flavour information is stored in the event as an AssociationVector which associates an object of type JetFlavourInfo to each of the jets.
The producer takes as input jets and hadron and partons selected by the HadronAndPartonSelector producer. The hadron and parton four-momenta are rescaled by a very small number (default rescale factor is 10e-18) which turns them into the so-called "ghosts". The "ghost" hadrons and partons are clustered together with all of the jet constituents. It is important to use the same clustering algorithm and jet size as for the original input jet collection. Since the "ghost" hadrons and partons are extremely soft, the resulting jet collection will be practically identical to the original one but now with "ghost" hadrons and partons clustered inside jets. The jet flavour is determined based on the "ghost" hadrons clustered inside a jet:
- jet is considered a b jet if there is at least one b "ghost" hadron clustered inside it (hadronFlavour = 5)
- jet is considered a c jet if there is at least one c and no b "ghost" hadrons clustered inside it (hadronFlavour = 4)
- jet is considered a light-flavour jet if there are no b or c "ghost" hadrons clustered inside it (hadronFlavour = 0)
To further assign a more specific flavour to light-flavour jets, "ghost" partons are used:
- jet is considered a b jet if there is at least one b "ghost" parton clustered inside it (partonFlavour = 5)
- jet is considered a c jet if there is at least one c and no b "ghost" partons clustered inside it (partonFlavour = 4)
- jet is considered a light-flavour jet if there are light-flavour and no b or c "ghost" partons clustered inside it. The jet is assigned the flavour of the hardest light-flavour "ghost" parton clustered inside it (partonFlavour = 1, 2, 3, or 21)
- jet has an undefined flavour if there are no "ghost" partons clustered inside it (partonFlavour = 0)
In rare instances a conflict between the hadron- and parton-based flavours can occur. In such cases it is possible to keep both flavours or to give priority to the hadron-based flavour. This is controlled by the 'hadronFlavourHasPriority' switch. The priority is given to the hadron-based flavour as follows:
- if hadronFlavour==0 && (partonFlavour==4 || partonFlavour==5): partonFlavour is set to the flavour of the hardest light-flavour parton clustered inside the jet if such parton exists. Otherwise, the parton flavour is left undefined
- if hadronFlavour!=0 && hadronFlavour!=partonFlavour: partonFlavour is set equal to hadronFlavour
The producer is also capable of assigning the flavour to subjets of fat jets, in which case it produces an additional AssociationVector providing the flavour information for subjets. In order to assign the flavour to subjets, three input jet collections are required:
- jets, in this case represented by fat jets
- groomed jets, which is a collection of fat jets from which the subjets are derived (e.g. pruned, filtered, soft drop, top-tagged, etc. jets)
- subjets, derived from the groomed fat jets
The "ghost" hadrons and partons clustered inside a fat jet are assigned to the closest subjet in the rapidity-phi space. Once hadrons and partons have been assigned to subjets, the subjet flavour is determined in the same way as for jets. The reason for requiring three jet collections as input in order to determine the subjet flavour is to avoid possible inconsistencies between the fat jet and subjet flavours (such as a non-b fat jet having a b subjet and vice versa) as well as the fact that re-clustering the constituents of groomed fat jets will generally result in a jet collection different from the input groomed fat jets. Also note that "ghost" particles generally cannot be clustered inside subjets in the same way this is done for fat jets. This is because some of the jet grooming techniques could reject such very soft particle. So instead, the "ghost" particles are assigned to the closest subjet.
Finally, "ghost" leptons can also be clustered inside jets but they are not used in any way to determine the jet flavour. This functionality is optional and is potentially useful to identify jets from hadronic taus.
For more details, please refer to https://twiki.cern.ch/twiki/bin/view/CMSPublic/SWGuideBTagMCTools
Definition at line 141 of file JetFlavourClustering.cc.
Public Member Functions inherited from edm::stream::EDProducer<>
1.8.5
