LoKi's Particle Functions

This lists a lot of the LoKi Functors. See DaVinciTutorial4 for a hands-on tutorial. A list with examples of use in CombineParticles can be found at LoKiHybridFilters. As neither are guaranteed to be a complete list, you can always see the DOxygen for the LoKi::Cuts namespace here.



ALL, C++: the instance of LoKi::BooleanConstant<const LHCb::Particle*>(true)

The most trivial "select-all" predicate which always returns true

ABSID, the instance of LoKi::Particles::AbsIdentifier()

The simple function which returns the absolute value of PDG-identifier of the particle:
 1000const LHCb::Particle* p = ... ;
 1010const double absid = ABSID( p ) ;
The special equality/non-equality operators against std::string and LHCb::ParticleID objects are defined:
 1000Range kaons = select ( "kaons" , "K+" == ABSID ) ; 
 1010Range nonmuons = select ( "!mu" , LHCb::ParticleID( 13 ) != ABSID ) ;
See also ID.

ADMASS, C++ type LoKi::Particles::AbsDeltaMass

The simple function which returns the absolute value of the deviation of the particle's mass from some reference value or the nominal mass:
 1000const LHCb::Particle* d0 = ... ;
 1010Fun dm = ADMASS ( 1.864 * GeV ) ; ///< constructor from the reference mass
 1020const double delta = dm ( d0 ) ; ///< evaluate abs(mass - 1.864 * GeV)
 1030
The function could be used with various constructors:
 1000const LHCb::Particle*       particle = ... ; // get the particle
 1010IParticlePropertySvc* ppsvc    = ... ; // get the service 
 1020const ParticleProperty& D0     = ... ; // get from the service 
 1030   
 1040Fun dm1 = ADMASS ( "D0" , ppsvc ) ; ///< constructor form the name and Service
 1050const double    dm1       = dm1 ( particle ) ;
 1060Fun dm2 = ADMASS ( 241  , ppsvc ) ; ///< constructor from PID and Service 
 1070const double    dm2       = dm2 ( particle ) ;
 1080Fun dm3 = ADMASS ( D0 ) ;   ///< constructor from ParticleProperty 
 1090const double    dm3       = dm3 ( particle ) ;
 1100Fun dm4 = ADMASS ( "D0" ) ; ///< constructor from the name 
 1110const double    mm4       = dm4 ( particle ) ;
 1120Fun dm5 = ADMASS ( LHCb::ParticleID ( 421 )  ) ; // constructor from PID
 1130const double    mm5       = dm5 ( particle ) ;
The later two constructors could be used only if LoKi Service, implementation of LoKi::ILoKiSvc insterface, is active. The function is very convinient to be used in the loops:
 1000Cut dm = ADMASS("phi(1020)") < 10 * MeV ; ///< create the cut
 1010for ( Loop phi = loop ( "K+ K-" , "phi(1020)") ; phi ; ++phi )
 1020   {
 1030     if ( dm ( phi ) ) { phi -> save ( "phi" ) ; } 
 1040   }
See also DMASS.

ADMMASS, C++ type LoKi::Particles::AbsDeltaMeasuredMass

The simple function which returns the absolute value of the deviation of the particle's measured mass from some refernece value or the nominal mass:
 1000const LHCb::Particle* d0 = ... ;
 1010Fun dm = ADMMASS ( 1.864 * GeV ) ; ///< constructor from the reference mass
 1020const double delta = dm ( d0 ) ; ///< evaluate abs( measuredMass - 1.864 * GeV)
 1030
The function could be used with various constructors:
 1000const LHCb::Particle*       particle = ... ; // get the particle
 1010IParticlePropertySvc* ppsvc    = ... ; // get the service 
 1020const ParticleProperty& D0     = ... ; // get from the service 
 1030   
 1040Fun dm1 = ADMMASS ( "D0" , ppsvc ) ; ///< constructor form the name and Service
 1050const double    dm1       = dm1 ( particle ) ;
 1060Fun dm2 = ADMMASS ( 241  , ppsvc ) ; ///< constructor from PID and Service 
 1070const double    dm2       = dm2 ( particle ) ;
 1080Fun dm3 = ADMMASS ( D0 ) ;   ///< constructor from ParticleProperty 
 1090const double    dm3       = dm3 ( particle ) ;
 1100Fun dm4 = ADMMASS ( "D0" ) ; ///< constructor from the name 
 1110const double    mm4       = dm4 ( particle ) ;
 1120Fun dm5 = ADMMASS ( LHCb::ParticleID ( 421 )  ) ; // constructor from PID
 1130const double    mm5       = dm5 ( particle ) ;
The later two constructors could be used only if LoKi Service, implementation of LoKi::ILoKiSvc insterface, is active. See also DMMASS.

BASIC

It is an alias for ISBASIC, see ISBASIC

CHILD, C++ type LoKi::Particles::ChildFunction

The function which delegates the evaluation of another function to the daugher particle:
 1000const LHCb::Particle* B = ... ;
 1010// pt of the first daughter:
 1020Fun fun1 = CHILD ( PT , 1 ) ;
 1030const double pt1 = fun1 ( B ) ; 
 1040// energy of the first daughter of the first daughter:
 1050Fun fun2 = CHILD ( E , 1 , 1 ) ;
 1060const double e11 = fun2 ( B ) ; 
Note:
  • The indices start from 1

CHILDFUN

It is an alias for CHILD, see CHILD

CHILDCUT, C++ type LoKi::Particles::ChildPredicate

The predicate which delegates the evaluation of another predicate to the daugher particle:
 1000const LHCb::Particle* B = ... ;
 1010// is the first daughter a pion?
 1020Cut cut1 = CHILDCUT ( "pi+" == ABSID , 1 ) ;
 1030const bool pion1 = cut1( B ) ; 
Note:
  • The indices start from 1

CHI2M, C++ type LoKi::Particles::DeltaMeasuredMassChi2

The simple function which returns the deviation of the the particle's measured mass from some refernece value or the nominal mass in units
 1000const LHCb::Particle* d0 = ... ;
 1010Fun chi2m = CHI2M ( 1.864 * GeV ) ; ///< constructor from the reference mass
 1020const double chi2  = chi2m ( d0 ) ; ///< evaluate chi2(mass - 1.864 * GeV)
 1030
The function could be used with various constructors:
 1000const LHCb::Particle*       particle = ... ; // get the particle
 1010IParticlePropertySvc* ppsvc    = ... ; // get the service 
 1020const ParticleProperty& D0     = ... ; // get from the service 
 1030   
 1040Fun dm1 = CHI2M ( "D0" , ppsvc ) ; ///< constructor form the name and Service
 1050const double    dm1       = dm1 ( particle ) ;
 1060Fun dm2 = CHI2M ( 241  , ppsvc ) ; ///< constructor from PID and Service 
 1070const double    dm2       = dm2 ( particle ) ;
 1080Fun dm3 = CHI2M ( D0 ) ;   ///< constructor from ParticleProperty 
 1090const double    dm3       = dm3 ( particle ) ;
 1100Fun dm4 = CHI2M ( "D0" ) ; ///< constructor from the name 
 1110const double    mm4       = dm4 ( particle ) ;
 1120Fun dm5 = CHI2M ( LHCb::ParticleID ( 421 )  ) ; // constructor from PID
 1130const double    mm5       = dm5 ( particle ) ;
The later two constructors could be used only if LoKi Service, the implementation of LoKi::ILoKiSvc insterface, is active.

CHI2MASS

It is an alias for CHI2M, see CHI2M

CHI2MIP

It is an alias for MIPCHI2, see MIPCHI2

CL, the instance of LoKi::Particles::ConfidenceLevel()

The simple function which returns the confedence level of the particle:
 1000const LHCb::Particle* p = ... ;
 1010const double cl = CL ( p ) ;

CLAPP, C++ type LoKi::Particles::ClosestApproach

The simple function which evaluated the distance of the closest approach between the particle and some reference particle. IDistanceCalculator is used for the evaluation.
 1000const LHCb::Particle* K = ... ;
 1010// find all "close" paricles:
 1020Range closest = select ( "closest" , CLAPP( K1 , geo() ) < 0.1 * mm ) ;

CLAPPCHI2, C++ type LoKi::Particles::ClosestApproachChi2

The simple function which evaluated the of the distance of the closest approach between the particle and some reference particle. IDistanceCalculator is used for the evaluation.
 1000const LHCb::Particle* K = ... ;
 1010// find all "close" paricles:
 1020Range closest = select ( "closest" , CLAPPCHI2( K1 , geo() ) < 9 ) ;

CONFLEV

It is an alias for CL, see CL

CONFLEVEL

It is an alias for CL, see CL

COUNTER, C++ type LoKi::Monitoring::Counter<const LHCb::Particle*>

The simple predicate, useful for monitoring of the another predicates. Essentially it monitors the performance (acceptance rate) of another predicate.

 1000// The predicate to be monitored:
 1010Cut cut = ... ;
 1020// the generic Counter:
 1030StatEntity* counter = ...;
 1040// Monitored predicate:
 1050Cut mon = COUNTER( cut , counter ) ;
 1060// use it!
 1070for ( ... ) 
 1080  {
 1090    ...
 1100    const LHCb::Particle* p = ... ;
 1110    const bool result = mon ( p  ) ; ///< use the predicate!
 1120    ...
 1130  }
 1140...
 1150info () 
 1160   << " The performace:  " << endreq 
 1170   << " # of entries       #" << counter->nEntries() << endreq 
 1180   << " Acceptance rate  (" << counter->eff()*100 
 1190   << " += "                     << counter->effErr() * 100 ) 
 1200   << ")%"       << endreq ;
 1210...
The generic counter of C++ type StatEntity could be either the local counter owned by the GaudiAlgorithm or GaudiTool base classes, or it could be the counter from IStatSvc or ICounterSvc services.

The alternative (and recommended!) way for creation of the monitored predicate is through the function monitor:

 1000// The predicate to be monitored:
 1010Cut cut = ... ;
 1020// the generic Counter:
 1030StatEntity* counter = ...;
 1040// Monitored predicate:
 1050Cut mon = monitor ( cut , counter ) ;
E.g. in the case of local counter, it could be:
 1000// The predicate to be monitored:
 1010Cut cut = ... ;
 1020// Monitored predicate:
 1030Cut mon = monitor ( cut , counter("SomeEfficiencyCounter") ) ;

The substitution of the predicate could be done on-flight without disturbing of the actual processing:

 1000// The regular predicate 
 1010Cut cut = ... ;
 1020if ( monitoring )  ///< add the monitoring capabilities (if needed) 
 1030 {
 1040    cut = monitor ( cut , counter("SomeEfficiencyCounter") ) ;
 1050 }
The string representation of the monitored predicate and the unique ID are delegated to the predicate itself, making the object non-reconstructable from its own string representation. It is done on-purpose to avoid any interference and disturbance with the regular procession.

CTAU

It is an alias for TIMEDIST, see TIMEDIST

CTAUDOT

It is an alias for TDOT, see TDOT

CTAUSIGN

It is an alias for TSIGND, see TSIGND

DANG

It is an alias for DIRA, see DIRA

DELTAR2

It is an alias for DR2, see DR2

DETA, C+ type LoKi::Particles::DeltaEta

The function which returns the value of for the particle's momenta with respect some reference momentum:
 1000const LHCb::Particle* jet = ... ;
 1010Fun deta = DETA ( jet->momentum() ) ;
 1020const LHCb::Particle* p = ... ;
 1030const double deltaEta = deta ( p ) ;

DIRA, C++ type LoKi::Particles::CosineDirectionAngle

The function evaluates the coside of the angle between the momentum of the particle and the direction vector from some reference vertex or 3D-point to the end-vertex of the particle:
 1000const LHCb::VertexBase* primary = ... ;
 1010const LHCb::Particle* B = ... ; // get the particle
 1020Fun dira = DIRA ( primary ) ;
 1030const double result = dira ( B ) ;

DMASS, C++ type LoKi::Particles::DeltaMass

The simple function which returns the deviation of the particle's mass from some refernece value or the nominal mass:
 1000const LHCb::Particle* d0 = ... ;
 1010Fun dm = DMASS ( 1.864 * GeV ) ; ///< constructor from the reference mass
 1020const double delta = dm ( d0 ) ; ///< evaluate (mass - 1.864 * GeV)
 1030
The function could be used with various constructors:
 1000const LHCb::Particle*       particle = ... ; // get the particle
 1010IParticlePropertySvc* ppsvc    = ... ; // get the service 
 1020const ParticleProperty& D0     = ... ; // get from the service 
 1030   
 1040Fun dm1 = DMASS ( "D0" , ppsvc ) ; ///< constructor form the name and Service
 1050const double    dm1       = dm1 ( particle ) ;
 1060Fun dm2 = DMASS ( 241  , ppsvc ) ; ///< constructor from PID and Service 
 1070const double    dm2       = dm2 ( particle ) ;
 1080Fun dm3 = DMASS ( D0 ) ;   ///< constructor from ParticleProperty 
 1090const double    dm3       = dm3 ( particle ) ;
 1100Fun dm4 = DMASS ( "D0" ) ; ///< constructor from the name 
 1110const double    mm4       = dm4 ( particle ) ;
 1120Fun dm5 = DMASS ( LHCb::ParticleID ( 421 )  ) ; // constructor from PID
 1130const double    mm5       = dm5 ( particle ) ;
The later two constructors could be used only if LoKi Service, implementation of LoKi::ILoKiSvc insterface, is active. See also ADMASS.

DMMASS, C++ type LoKi::Particles::DeltaMeasuredMass

The simple function which returns the deviation of the particle's measured mass from some refernece value or the nominal mass:
 1000const LHCb::Particle* d0 = ... ;
 1010Fun dm = DMMASS ( 1.864 * GeV ) ; ///< constructor from the reference mass
 1020const double delta = dm ( d0 ) ; ///< evaluate ( measuredMass - 1.864 * GeV)
 1030
The function could be used with various constructors:
 1000const LHCb::Particle*       particle = ... ; // get the particle
 1010IParticlePropertySvc* ppsvc    = ... ; // get the service 
 1020const ParticleProperty& D0     = ... ; // get from the service 
 1030   
 1040Fun dm1 = DMMASS ( "D0" , ppsvc ) ; ///< constructor form the name and Service
 1050const double    dm1       = dm1 ( particle ) ;
 1060Fun dm2 = DMMASS ( 241  , ppsvc ) ; ///< constructor from PID and Service 
 1070const double    dm2       = dm2 ( particle ) ;
 1080Fun dm3 = DMMASS ( D0 ) ;   ///< constructor from ParticleProperty 
 1090const double    dm3       = dm3 ( particle ) ;
 1100Fun dm4 = DMMASS ( "D0" ) ; ///< constructor from the name 
 1110const double    mm4       = dm4 ( particle ) ;
 1120Fun dm5 = DMMASS ( LHCb::ParticleID ( 421 )  ) ; // constructor from PID
 1130const double    mm5       = dm5 ( particle ) ;
The later two constructors could be used only if LoKi Service, implementation of LoKi::ILoKiSvc insterface, is active. See also ADMMASS.

DPHI, C+ type LoKi::Particles::DeltaPhi

The function which returns the value of for the particle's momenta with respect some reference momentum:
 1000const LHCb::Particle* jet = ... ;
 1010Fun dphi = DPHI ( jet->momentum() ) ;
 1020const LHCb::Particle* p = ... ;
 1030const double deltaPhi = dphi ( p ) ;

DR2, C+ type LoKi::Particles::DeltaR2

The function which returns the value of for the particle's momenta with respect some reference momentum:
 1000const LHCb::Particle* jet = ... ;
 1010Fun dr2 = DR2 ( jet->momentum() ) ;
 1020const LHCb::Particle* p = ... ;
 1030const double deltaR2 = dr2 ( p ) ;

E, the instance of LoKi::Particles::Energy()

The simple function which returns the value of the particle's energy:
 1000Range energetic = select ( "energetic" ,  E > 10 * GeV ) ; 

ETA, the instance of LoKi::Particles::PseudoRapidity()

The simple function which returns the pseudorapidity:
 1000Range some = select ( "eta<4" ,  ETA < 4 ) ; 

EQUALTO, C++ type LoKi::EqualToValue<const LHCb::Particle*>

The simple predicate which checks if the value of the certain function equal to some predefined value:
 1000Range k1 = select ( "positive" , EQUALTO( Q , +1.0 ) ) ;
 1010Range k2 = select ( "positive" , Q == +1 ) ; ///< the same
 1020

FILTER, C++ type LoKi::Particles::Filter,

The adapter predicate, which allows to use IFilterCriterion tool as LoKi predicate:
 1000IFilterCriterion* criterion = ... ;
 1010// select particles accroding to criterion:
 1020Range good = select ( "good" , FILTER ( criterion )  ) ; ///< use the tool 
 1030

FROM

It is an alias for ISINTREE, see ISINTREE

FROMTREE

It is an alias for ISINTREE, see ISINTREE

HASCALOS

It is an alias for PPHASCALOS, see PPHASCALOS

HASINFO, C++ type LoKi::Particles::HasInfo

The predicate which checks the presence of the entries in "extraInfo" field of the particle:
 1000Range weighted = select ( "withweight" , HASINFO ( LHCb::Particle::Weight) ) ; 
 1010const bool good = HASKEY( p ) ;

HASKEY, the instance of LoKi::Particles::HasKey()

The predicate which returns true if the argument has the assigned key:
 1000const LHCb::Particle* p =  ... ;
 1010const bool good = HASKEY( p ) ;
For invalid arguments false is returned. See also KEY.

HASMUON

It is an alias for PPHASMUON, see PPHASMUON

HASPINFO

It is an alias for HASINFO, see HASINFO

HASPROTO, the instance of LoKi::Particles::HasProto()

The predicate which check the presence of the protoparticle:
 1000// select the basic particles with valid protoparticle:
 1010Range withProto = select ( "WithProto" , HASPROTO ) ;

HASPROTOS, C++ type LoKi::Particles::HasProtos

The predicate which check the presence the protoparticles from the list:
 1000SEQUENCE protoparticles = ... ;
 1010// select only particles, which are "independent" from the protoparticles in the list
 1020Range good = select ( "Good" , !HASPROTOS( protoparticles )  ) ;

HASPROTOSINTREE, C++ type LoKi::Particles::HasProtosInTree

The predicate which check the presence the protoparticles from the list in thedecay tree of the particles:
 1000SEQUENCE protoparticles = ... ;
 1010// select only particles, which are "independent" from the protoparticles in the list
 1020Range good = select ( "Good" , !HASPROTOSINTREE( protoparticles )  ) ;

HASRICH

It is an alias for PPHASRICH, see PPHASRICH

HASSTATE, C++ type LoKi::Particles::TrackHasState

The predicate which evaluates LHCb::Track::hasStateAt
 1000// select only particles from tracks whcih has state at TT:
 1010Range good = select ( "Good" , HASTRACK && HASSTATE ( LHCb::State::AtTT )  ) ;

HASTRACKS, C++ type LoKi::Particles::HasTracks

The predicate which check the presence the tracks from the list:
 1000SEQUENCE tracks = ... ;
 1010// select only particles, which are "independent" from the tracks in the list
 1020Range good = select ( "Good" , !HASTRACKS( tracks )  ) ;

HASTRACKS, C++ type LoKi::Particles::HasTracks

The predicate which check the presence the tracks from the list in the decay tree of the particle:
 1000SEQUENCE tracks = ... ;
 1010// select only particles, which are "independent" from the tracks in the list
 1020Range good = select ( "Good" , !HASTRACKSINTREE( tracks )  ) ;

HASVERTEX, the instance of LoKi::Particles::HasVertex()

The predicate which check the presence of the vertex:
 1000// select the particles with the vertex:
 1010Range withVertex = select ( "WithVertex" , HASVERTEX ) ;

ID, the instance of LoKi::Particles::Identifier()

The simple function which returns the value of PDG-identifier of the particle:
 1000const LHCb::Particle* p = ... ;
 1010const double id = ID( p ) ;
The special equality/non-equality operators against std::string and LHCb::ParticleID objects are defined:
 1000Range kaons = select ( "kaons" , "K+" == ID ) ; 
 1010Range notgamma = select ( "!gamma" , LHCb::ParticleID( 22 ) != ID ) ;
For the invalid argument LoKi::Constanst::InvalidID is returned. See also ABSID.

INFO, C++ type LoKi::Particles::Info

The function which extract "extra" information using LHCb::Particle::info(...) method:
 1000const LHCb::Particle* p =  ... ;
 1010const int index = ... ;
 1020Fun info = INFO( index , -1000.0 ) ;
 1030const double result = info ( p ) ;

INTES, C++ type LoKi::Particles::InTES

The predicate which checks the certain the location of particle in Transient Event Store. It is useful to separate the input particles from the different TES locations:
 1000Range noPID = select ( "NoPID" , INTES("NoPID", false) ) ;
The second argument switch on/off the match of the full TES path. The leading "/Event/" could be always omitted.

INTREE, C++ type LoKi::Particles::InTree

The predicate which recursively checks the presence in the decay tree of the particle the (grand)-daughter which satisfies the specified criteria:
 1000const LHCb::Particle* B = ... ;
 1010// check the presence of phi in the decay tree:
 1020Cut good = INTREE( "phi(1020)" == ID ) ;
 1030const bool hasPhiInDecay = good ( B ) ;

IP, C++ type LoKi::Particles::ImpPar

The function which calculates the impact parameter of the particle with respect to some vertex or 3D-point using IDistanceCalculator tool:
 1000const LHCb::VertexBase* primary = ... ;
 1010// get all particles with large impact parameters:
 1020Range largeIP = select ( "notFromPV" , 0.2 * mm  < IP ( primary , geo() ) ) ;

IPCHI2, C++ type LoKi::Particles::ImpParChi2

The function which calculates the of the impact parameter of the particle with respect to some vertex or 3D-point using IDistanceCalculator tool:
 1000const LHCb::VertexBase* primary = ... ;
 1010// get all particles with large impact parameters:
 1020Range largeIP = select ( "notFromPV" , 4 < IPCHI2 ( primary , geo() ) ) ;

IPMIN, C++ type LoKi::Particles::MinImpPar

The function which calculates the minimum value of the impact parameter of the particle with respect to some set of reference vertices or 3D-point using IDistanceCalculator tool:
 1000SEQUENCE primaries = ... ;
 1010// get all particles with large impact parameters:
 1020Range largeIP = select ( "notFromPV" , 0.2 * mm  < IPMIN ( primaries , geo() ) ) ;

IS, C++ type LoKi::Particles::IsAParticle

The predicate which checks if th eparticle is contained in other list:
 1000SEQUENCE particles = ... ;
 1010// get the particle not from the list
 1020Range notFromList = select ( "notFromList" , !IS( particles ) ) ;

ISBASIC, the instance of LoKi::Particles::IsBasic()

The predicate which checks if the particle is a basic particle, LHCb::Particle::isBasic:
 1000Range basic = select ( "basic" , ISBASIC ) ;

ISDOWN, the instance of EQUALTO(TRTYPE,LHCb::Track::Downstream)

The predicate which checks the type of underlying track:
 1000// get the particles from downstream tracks 
 1010Range down = select ( "Down" , HASTRACK && ISDOWN  ) ;

ISINTREE, C++ type LoKi::Particles::IsAParticle

The predicate which checks if the particle or any of its daughters in the list:
 1000SEQUENCE particles = ... ;
 1010// get the particle not from the list
 1020Range notFromList = select ( "notFromList" , !ISINTREE ( particles ) ) ;

ISLONG, the instance of EQUALTO(TRTYPE,LHCb::Track::Long)

The predicate which checks the type of underlying track:
 1000// get the particles from long track 
 1010Range longs = select ( "Long" , HASTRACK && ISLONG  ) ;

ISMUON, the instance of LoKi::Particles::IsMuon()

The predicate which checks LHCb::MuonPID::isMuon:
 1000Range isMuon = select ( "isMuon" , ISBASIC && ISMUON ) ;

ISTTRACK, the instance of EQUALTO(TRTYPE,LHCb::Track::Ttrack)

The predicate which checks the type of underlying track:
 1000// get the particles from T-tracks 
 1010Range ts = select ( "T" , HASTRACK && ISTTRACK  ) ;

ISUP, the instance of EQUALTO(TRTYPE,LHCb::Track::Upstream)

The predicate which checks the type of underlying track:
 1000// get the particles from upstream tracks 
 1010Range ups = select ( "Up" , HASTRACK && ISUP  ) ;

KEY, the instance of LoKi::Particles::Key()

The function which returns the value of the assigned key.
 1000const LHCb::Particle* p =  ... ;
 1010const double key = KEY( p ) ;
For invalid arguments, of if no key is assigned LoKi::Constants::InvalidKey is returned. See also HASKEY

LV0, C++ type LoKi::Particles::DecayAngle,

The function evaluated the cosine of the angle between the daughters's momentum and the mother flight direction in the rest system of the mother particle. For two-body decays it is just a polarization angle of the mother particle:
 1000const LHCb::Particle* p =  ... ;
 1010Fun fun = LV0(1) ; // the dacy angle of the first daughte
 1020const double result = fun ( B ) ;
Note:
  • The name comes from KAL language
  • The indices start from 1

LV01, the instance of LoKi::Particles::DecayAngle(1),

The function evaluated the cosine of the angle between the first daughters's momentum and the mother flight direction in the rest system of the mother particle.
 1000const LHCb::Particle* p =  ... ;
 1010const double result = LV01 ( B ) ;
The name comes from KAL language. See LV0

LV02, the instance of LoKi::Particles::DecayAngle(2),

The function evaluated the cosine of the angle between the second daughters's momentum and the mother flight direction in the rest system of the mother particle.
 1000const LHCb::Particle* p =  ... ;
 1010const double result = LV02 ( B ) ;
The name comes from KAL language. See LV0

LV03, the instance of LoKi::Particles::DecayAngle(3),

The function evaluated the cosine of the angle between the third daughters's momentum and the mother flight direction in the rest system of the mother particle.
 1000const LHCb::Particle* p =  ... ;
 1010const double result = LV03 ( B ) ;
The name comes from KAL language. See LV0

LV04, the instance of LoKi::Particles::DecayAngle(4),

The function evaluated the cosine of the angle between the fourth daughters's momentum and the mother flight direction in the rest system of the mother particle.
 1000const LHCb::Particle* p =  ... ;
 1010const double result = LV04 ( B ) ;
The name comes from KAL language. See LV0

M, the instance of type LoKi::Particles::Mass()

The simple function which returns the kinematical mass of the particle , using Gaudi::LorentzVector::Mass method:
 1000const LHCb::Particle* p = ... ;
 1010const double mass = M( p ) ;  

MASS, C++ type LoKi::Particles::InvariantMass

The simple function which returns the invariant mass of the subcombinations of daughter particles.
 1000const LHCb::Particle* p = ... ;
 1010Fun m12 = MASS(1,2) ; ///< the invariant mass of the first and the second daughter particles
 1020const double mass  = m12( p )  ;  
Note:
  • the indices for daughter particles start from 1
  • index 0 corresponds to the mother particle itself

MAXTREE, C++ type LoKi::Particles::MaxTree

The function with scans the decay tree and return the maximal value of another function, evaluated for the (grand)daughter particles which satisfy the certain criteria
 1000const LHCb::Particle* B = ... ;
 1010// maximal deviation from nominal mass for all phis in the tree:
 1020Fun fun = MAXTREE ( ADMASS("phi(1020)") , "phi(1020)" == ID , -1 ) ;
 1030const double maxDM = fun ( B ) ;

MM, the instance of LoKi::Particles::MeasuredMass()

The simple function which returns the measured mass of the particle, using LHCb::Particle::measuredMass method:
 1000const LHCb::Particle* p = ... ;
 1010const double measuredMass = MM( p ) ;  

MINCLAPP, C++ type LoKi::Particles::MinClosestApproach

The simple function which returns the minimum of the closest approached of the particle against some set of other particles. IDistanceCalculator is used for evaluation.
 1000SEQUENCE particles = ... ;
 1010Fun fun = MINCLAPP( particles, geo() ) ;
 1020const LHCb::Particle* p = ... ;
 1030const double minDOCA = fun ( p ) ;  

MINCLAPPCHI2, C++ type LoKi::Particles::MinClosestApproachChi2

The simple function which returns the minimum of the closest approached of the particle against some set of other particles. IDistanceCalculator is used for evaluation.
 1000SEQUENCE particles = ... ;
 1010Fun fun = MINCLAPPCHI2( particles, geo() ) ;
 1020const LHCb::Particle* p = ... ;
 1030const double minDOCAchi2 = fun ( p ) ;  

MINIP

It is an alias for IPMIN, see IPMIN

MINTREE, C++ type LoKi::Particles::MinTree

The function with scans the decay tree and return the minimal value of another function, evaluated for the (grand)daughter particles which satisfy the certain criteria
 1000const LHCb::Particle* B = ... ;
 1010// minimal transverse momentum of the basic particle
 1020Fun fun = MINTREE ( PT , BASIC , -10 * TeV ) ;
 1030const double minPT = fun ( B ) ;

MINVD

It is an alias for VDMIN, see VDMIN

MINVDCHI2

It is an alias for VDMINCHI2, see VDMINCHI2

MIP

It is an alias for IPMIN, see IPMIN

MIPCHI2, C++ type LoKi::Particles::MinImpParChi2

The function which calculates the minimum value of the impact parameter of the particle with respect to some set of reference vertices or 3D-point using IDistanceCalculator tool:
 1000SEQUENCE primaries = ... ;
 1010// get all particles with large impact parameters:
 1020Range largeIP = select ( "notFromPV" , 4 < MINCHI2 ( primaries , geo() ) ) ;

MULTTREE, C++ type LoKi::Particles::MultTree

The function with accumulate (by multiplication) the value of another function for all daughter particles inthe decay tree, which satisfy the certain criteria
 1000const LHCb::Particle* B = ... ;
 1010// the product of all weigth for the composed particles:
 1020Fun fun = MULTTREE ( W , !BASIC , 1.0 ) ;
 1030const double multW = fun ( B ) ;

M12, the instance of LoKi::Particles::InvariantMass(1,2)

The simple function which returns the invariant mass of the first and the second daughter particles
 1000const LHCb::Particle* p = ... ;
 1010// the invariant mass of the first and the second daughter particles
 1020const double mass  = M12( p )  ;  
See MASS

M13, the instance of LoKi::Particles::InvariantMass(1,3)

The simple function which returns the invariant mass of the first and the third daughter particles
 1000const LHCb::Particle* p = ... ;
 1010// the invariant mass of the first and the third daughter particles
 1020const double mass  = M13( p )  ;  
See MASS

M14, the instance of LoKi::Particles::InvariantMass(1,4)

The simple function which returns the invariant mass of the first and the fourth daughter particles
 1000const LHCb::Particle* p = ... ;
 1010// the invariant mass of the first and the fourth daughter particles
 1020const double mass  = M14( p )  ;  
See MASS

M23, the instance of LoKi::Particles::InvariantMass(2,3)

The simple function which returns the invariant mass of the second and the third daughter particles
 1000const LHCb::Particle* p = ... ;
 1010// the invariant mass of the second and the third daughter particles
 1020const double mass  = M23( p )  ;  
See MASS

M24, the instance of LoKi::Particles::InvariantMass(2,4)

The simple function which returns the invariant mass of the second and the fourth daughter particles
 1000const LHCb::Particle* p = ... ;
 1010// the invariant mass of the second and the fourth daughter particles
 1020const double mass  = M24( p )  ;  
See MASS

M34, the instance of LoKi::Particles::InvariantMass(3,4)

The simple function which returns the invariant mass of the third and the fourth daughter particles
 1000const LHCb::Particle* p = ... ;
 1010// the invariant mass of the third and the fourth daughter particles
 1020const double mass  = M34( p )  ;  
See MASS

NDAUGS, the instance of LoKi::Particles::NumberOfDaughters()=

The simple function which return number of daughter particles, LHCb::Particle::daughters().size():
 1000/// select two body B-decays:
 1010Range twobody = select ( "2" , 2 == NDAUGS ) ;

NDAUGHTERS

It is an alias for NDAUGS, see NDAUGS

NINTREE, C++ type LoKi::Particles::NinTree

The function with returns the number of the (grand)daughters inthe decay tree of the particle which satisfies the specified criteria:
 1000const LHCb::Particle* B = ... ;
 1010// select the particles with at least tho kaons in the decay tree 
 1020Range with2K = select ( "With2Kaons" , 1.9 < NINTREE( "K+" == ABSID ) )  

NONE, the instance of LoKi::BooleanConstant<const LHCb::Particle*>(false)

The most trivial "select-none" predicate which always returns false

ONE, the instance of LoKi::Constant<const LHCb::Particle*>(1)

The trivial function which always returns 1

P, the instance of type LoKi::Particles::Momentum()

The simple function which returns the value of the particle's momentum:
 1000Range energetic = select ( "energetic" ,  P > 10 * GeV ) ; 

P2, the instance of LoKi::Particles::Momentum2()

The simple function which returns the squared value of the particle's momentum:
 1000const LHCb::Particle* B =  ... ;
 1010const double p2 = P2( B ) ;

PALL

It is an alias for ALL, see ALL

PFALSE

It is an alias for NONE, see NONE

PHASINFO

It is an alias for HASINFO, see HASINFO

PHI, the instance of LoKi::Particles::Phi()

The simple function which returns the asimuthal angle
 1000const LHCb::Particle* p = ... ;
 1010const double phi = PHI( p ) ;  

PIDe, The instance of LoKi::Particles::ProtoInfo( LHCb::ProtoParticle::CombDLLe , 0 , -1000 )

Simple function which returns the combined identification for the electron hypothesis:
 1000// get all good electrons:
 1010Range electrons = select ( "e" , "e+" == ABSPID && 2 < PIDe ) ;
See PPINFO.

PIDmu, The instance of LoKi::Particles::ProtoInfo( LHCb::ProtoParticle::CombDLLmu , 0 , -1000 )

Simple function which returns the combined identification for the muon hypothesis:
 1000// get all good muons:
 1010Range muons = select ( "mu" , "mu+" == ABSPID && -10 < PIDmu ) ;
See PPINFO.

PIDk, The instance of LoKi::Particles::ProtoInfo( LHCb::ProtoParticle::CombDLLk , 0 , -1000 )

Simple function which returns the combined identification for the kaon hypothesis:
 1000// get all good kaons:
 1010Range kaons = select ( "K" , "K+" == ABSPID && -2 < PIDK ) ;
See PPINFO.

PIDp, The instance of LoKi::Particles::ProtoInfo( LHCb::ProtoParticle::CombDLLp , 0 , -1000 )

Simple function which returns the combined identification for the proton hypothesis:
 1000// get all good protons:
 1010Range protons = select ( "p" , "p+" == ABSPID && -5 < PIDp ) ;
See PPINFO.

PIDpi, The instance of LoKi::Particles::ProtoInfo( LHCb::ProtoParticle::CombDLLpi , 0 , -1000 )

Simple function which returns the combined identification for the pion hypothesis:
 1000// get all good pions:
 1010Range pions = select ( "mu" , "pi+" == ABSPID && -10 < PIDpi ) ;
See PPINFO. Note:
  • according to the convention, it is set to 0

PINFO

It is an alias for INFO, see INFO

PINTES

It is an alias for INTES, see INTES

PLOT, C++ type LoKi::Monitoring::Plot<const LHCb::Particle*>

The simple function, useful for monitoring of the another function. Essentially it applies the noather function and fills the histogram with the results.

 1000// The function to be monitored:
 1010Fun fun = ... ;
 1020// the histogram
 1030AIDA::IHistogramID* histo = ... ;
 1040// Monitored function:
 1050Fun mon = PLOT ( fun , histo ) ;
 1060// use it!
 1070for ( ... ) 
 1080  {
 1090    ...
 1100    const LHCb::Particle* p = ... ;
 1110    const double result = mon ( p  ) ; ///< use the function!
 1120    ...
 1130  }
 1140...

The alternative (and recommended!) way for creation of the monitored function is through the function monitor:

 1000// The function to be monitored:
 1010Fun fun = ... ;
 1020// the histogram
 1030AIDA::IHistogramID* histo = ... ;
 1040// Monitored function:
 1050Fun mon = monitor ( fun , histo ) ;

The substitution of the function could be done on-flight without disturbing of the actual processing:

 1000// The regular function
 1010Fun fun = ... ;
 1020if ( monitoring )  ///< add the monitoring capabilities (if needed) 
 1030 {
 1040    AIDA::IHistogram1D histo = ... ;
 1050    fun = monitor ( fun , histo ) ;
 1060 }
The string representation of the monitored function and the unique ID are delegated to the function itself, making the object non-reconstructable from its own string representation. It is done on-purpose to avoid any interference and disturbance with the regular procession.

PNONE

It is an alias for NONE, see NONE

PONE

It is an alias for ONE, see ONE

PPHASINFO, C++ type LoKi::Particles::ProtoHasInfo

The simple predicated which checks LHCb::ProtoParticle::hasInfo for the underlying protoparticle:
 1000// get all particles where protoparticle has PhotonID infomration:
 1010Range withPhotonID = select ( "Good" , BASIC && PPHASINFO( LHCb::ProtoParticle::PhotonID ) ) ;

PPHASCALOS, The instance of LoKi::Particles::ProtoHasCaloHypos()

The simple predicated which checks the existence of LHCb::ProtoParticle::calos for the underlying protoparticle:
 1000// get all particles where protoparticle has CaloHypo object
 1010Range withCalo = select ( "Good" , BASIC && PPHASCALOS ) ;

PPHASMUON, The instance of LoKi::Particles::ProtoHasMuonPID()

The simple predicated which checks the existence of LHCb::ProtoParticle::muonPID for the underlying protoparticle:
 1000// get all particles where protoparticle has RichPID object
 1010Range withMuonID = select ( "Good" , BASIC && PPHASMUON ) ;

PPHASRICH, The instance of LoKi::Particles::ProtoHasRichPID()

The simple predicated which checks the existence of LHCb::ProtoParticle::richPID for the underlying protoparticle:
 1000// get all particles where protoparticle has RichPID object
 1010Range withRichID = select ( "Good" , BASIC && PPHASRICH ) ;

PPINFO, C++ type LoKi::Particles::ProtoInfo

The function which delegates the evaluation of LHCb::ProtoParticle::info for the underlying protoparticle:
 1000// get all particles where protoparticle has good RichPion information:
 1010Range withGoodRichID = select ( "RICH" , BASIC &&  -5 < PPINFO( LHCb::ProtoParticle::RichPion , 0 , -1000 ) ) ;

PROTOS

It is an alias for HASPROTOS, see HASPROTOS

PROTOSINTREE

It is an alias for HASPROTOSINTREE, see HASPROTOSINTREE

PSAME

It is an alias for SAME, see SAME

PSWITCH

It is an alias for SWITCH, see SWITCH

PT, the instance of LoKi::Particles::TransverseMomentum()

The simple function which returns the particle's transverse momentum:
 1000const LHCb::Particle* B =  ... ;
 1010const double pt = PT ( B ) ;

--+++ PTDIR, C++ type LoKi::Particles::TransverseMomentumRel The simple function which evaluates the the particle's transverse momentum with respect to some 3D or Lorentz vector:

 1000const LHCb::Particle* jet =  ... ;
 1010Fun pt = PTDIR ( jet->momentum() ) ;
 1020const LHCb::Particle* mu = ... ;
 1030const double result = pt ( mu )  ; /// evaluate pt with respect to jet axis
 1040

PTREL

It is an alias for PTDIR, see PTDIR

PTRUE

It is an alias for ALL, see ALL

PVALID

It is an alias for VALID, see VALID

PVTRACK, C++ type LoKi::Particles::HasTracksFromPV

The simple predicate which evaluates to true for the basic particle, which directly participate into the primary vertex recontruction:
 1000const LHCb::RecVertex* primary =  ... ;
 1010// select only particle not used for PV recontruction:
 1020Range good = select ( "Good" , BASIC && !PVTRACK( primary ) ) ;

PVTRACKINTREE, C++ type LoKi::Particles::HasTracksFromPVInTree

The simple predicate which evaluates to true for the particles which directly or indirectly participate into the primary vertex recontruction:
 1000const LHCb::RecVertex* primary =  ... ;
 1010// select only particle not used for PV recontruction:
 1020Range good = select ( "Good" , !PVTRACKINTREE ( primary ) ) ;

PX, the instance of LoKi::Particles::MomentumX()

The simple function which returns X-component of the particle's momentum:
 1000const LHCb::Particle* B =  ... ;
 1010const double px = PX ( B ) ;

PY, the instance of LoKi::Particles::MomentumY()

The simple function which returns Y-component of the particle's momentum:
 1000const LHCb::Particle* B =  ... ;
 1010const double py = PY ( B ) ;
For the invalid argument LoKi::Constanst::InvalidMomentum is returned.

PZ, the instance of LoKi::Particles::MomentumZ()

The simple function which returns Z-component of the particle's momentum:
 1000const LHCb::Particle* B =  ... ;
 1010const double pz = PZ ( B ) ;
For the invalid argument LoKi::Constanst::InvalidMomentum is returned.

PZERO

It is an alias for ZERO, see ZERO

Q, the instance of LoKi::Particles::Charge()

The function which evaluates the charge of the particle, using the information from LHCb::ParticleID.
 1000const LHCb::Particle* p = ... ;
 1010const bool positive = 0 < Q ( p ) ;
LoKi::Constants::InvalidCharge is returned for invalid arguments. See also SUMQ

SAME, C++ type LoKi::TheSame<const LHCb::Particle>

The predicate which check if the particle is the same as some reference particle.
 1000const LHCb::Particle* p1 = ... ;
 1010Cut same = SAME ( p1 ) ;
 1020
 1030const LHCb::Particle* p2 = ... ;
 1040const bool theSame = same  ( p2 ) ;

STAT, C++ type LoKi::Monitoring::Stat<const LHCb::Particle*>

The simple function, useful for monitoring of the another function. Essentially it monitors the results of another function.

 1000// The function to be monitored:
 1010Fun fun = ... ;
 1020// the generic Counter:
 1030StatEntity* counter = ...;
 1040// Monitored function:
 1050Fun mon = STAT ( fun , counter ) ;
 1060// use it!
 1070for ( ... ) 
 1080  {
 1090    ...
 1100    const LHCb::Particle* p = ... ;
 1110    const double result = mon ( p  ) ; ///< use the function!
 1120    ...
 1130  }
 1140...
 1150info () 
 1160   << " The performace:  " << endreq 
 1170   << " # of entries       #" << counter->nEntries() << endreq 
 1180   << " Total sum           "  << counter->flag () << endreq 
 1190   << " Mean+-RMS        "  << counter->flagMean() 
 1200   << "+-" << counter->flagRMS()      << endreq 
 1210   << " Min/Max             "   << counter->flagMin() 
 1220   << "/"                            << counter->flagMax() << endreq ;
 1230...
The generic counter of C++ type StatEntity could be either the local counter owned by the GaudiAlgorithm or GaudiTool base classes, or it could be the counter from IStatSvc or ICounterSvc services.

The alternative (and recommended!) way for creation of the monitored function is through the function monitor:

 1000// The function to be monitored:
 1010Fun fun = ... ;
 1020// the generic Counter:
 1030StatEntity* counter = ...;
 1040// Monitored function:
 1050Fun mon = monitor ( fun , counter ) ;
E.g. in the case of local counter, it could be:
 1000// The function to be monitored:
 1010Fun fun = ... ;
 1020// Monitored function:
 1030Fun mon = monitor ( fun , counter("SomeEfficiencyCounter") ) ;

The substitution of the function could be done on-flight without disturbing of the actual processing:

 1000// The regular function
 1010Fun fun = ... ;
 1020if ( monitoring )  ///< add the monitoring capabilities (if needed) 
 1030 {
 1040    fun = monitor ( fun , counter("SomeEfficiencyCounter") ) ;
 1050 }
The string representation of the monitored function and the unique ID are delegated to the function itself, making the object non-reconstructable from its own string representation. It is done on-purpose to avoid any interference and disturbance with the regular procession.

SWITCH, C++ type LoKi::Switch<const LHCb::Particle*>

The function which acts according the rule: result = condition ? function1 : function2:
 1000Fun fun = SWITCH ( 0 < Q , PT ,  1/PT ) ; 

SUMQ, the instance of LoKi::Particles::SumCharge()

The function which evaluates the charge of the particle. For composed particles the charge is defined as the recursive sum over the charged all daughter particles, for the basic particles the information from LHCb::ParticleID is used
 1000const LHCb::Particle* B = ... ;
 1010const bool positive = 0 < SUMQ ( B ) ;
See also Q

SUMTREE, C++ type LoKi::Particles::SumTree

The function with accumulate (by addition) the value of another function for all daughter particles inthe decay tree, which satisfy the certain criteria
 1000const LHCb::Particle* B = ... ;
 1010// get th ealgenrac sum of all transverse momenta for the pions
 1020Fun fun = SUMTREE ( PT , "pi+" == ABSID , 0.0 ) ;
 1030const double sumPt = fun ( B ) ;

TD

It is an alias for TIMEDIST, see TIMEDIST

TDIST

It is an alias for TIMEDIST, see TIMEDIST

TDSIGN

It is an alias for TSIGND, see TSIGND

TIMEDIST, C++ type LoKi::Particles::TimeDistance,

The function evaluates the proper lifetime of the particle between "end-vertex" and some reference vertex or 3D-point. The function LoKi::Particles::VertexDistance is used for evaluation of geometry distance.
 1000const LHCb::VertexBase* primary ;
 1010Fun fun = TIMEDIST ( primary ) )
 1020const LHCb::Particle* B = ... ;
 1030const bool ctau = fun  ( B ) ;

TRACKFROMPV

It is an alias for PVTRACK, see PVTRACK

TRACKFROMPVINTREE

It is an alias for PVTRACKINTREE, see PVTRACKINTREE

TRACKS

It is an alias for HASTRACKS, see HASTRACKS

TRACKSINTREE

It is an alias for HASTRACKSINTREE, see HASTRACKSINTREE

TRCHI2, the instance of LoKi::Particles::TrackChi2(),

The function returns LHCb::Track::chi2 for the underlying track:
 1000// get only good tracks with small chi2:
 1010Range good = select ( "good" , HASTRACK && 100 > TRCHI2 ) ;  

TRCHI2DOF, the instance of LoKi::Particles::TrackChi2PerDoF(),

The function returns LHCb::Track::chi2PerDoF for the underlying track:
 1000// get only good tracks with small chi2:
 1010Range good = select ( "good" , HASTRACK && 3 > TRCHI2DOF ) ;  

TRHISTORY, the instance of LoKi::Particles::TrackHistory(),

The function returns LHCb::Track::history for the underlying track:

TRHISTORYFIT, the instance of LoKi::Particles::TrackHistoryFit(),

The function returns LHCb::Track::historyFit for the underlying track:

TRSTATUS, the instance of LoKi::Particles::TrackStatus(),

The function returns LHCb::Track::status for the underlying track:

TRTYPE, the instance of LoKi::Particles::TrackType(),

The function returns LHCb::Track::type for th eunderlying track:
 1000// get only long tracks:
 1010Range good = select ( "long" , HASTRACK && LHCb::Track::Long == TRTYPE ) ;  

TSIGND, C++ type LoKi::Particles::TimeSignedDistance,

The function evaluates the proper lifetime of the particle between "end-vertex" and some reference vertex or 3D-point. The function LoKi::Particles::VertexSignedDistance is used for evaluation of geometry distance.
 1000const LHCb::VertexBase* primary ;
 1010Fun fun = TSIGND ( primary ) )
 1020const LHCb::Particle* B = ... ;
 1030const bool ctau = fun  ( B ) ;

TDOT, C++ type LoKi::Particles::TimeDotDistance,

The function evaluates the proper lifetime of the particle between "end-vertex" and some reference vertex or 3D-point along the particle momentum. The function LoKi::Particles::VertexDotDistance is used for evaluation of geometry distance.
 1000const LHCb::VertexBase* primary ;
 1010Fun fun = TDOTD ( primary ) )
 1020const LHCb::Particle* B = ... ;
 1030const bool ctau = fun  ( B ) ;

VALID, the instance of LoKi::Valid<const LHCb::Particle*>()

The trivial predicate which checks the validity of the argument:
 1000const std::vector<const LHCb::Particle*>& p = ... ;
 1010// check for invalid pointers:
 1020if ( std::find_if ( p.begin() , p.end() , !VALID ) != p.end() ) { ... there are null pointers ... }  

VD, C++ type LoKi::Particles::VertexDistance

The simple function which evaluates the geometrical 3D-distance between the end-vertex of the particle, , and some reference vertex or 3D-point, , as :
 1000const LHCb::VertexBase* primary = ... ;
 1010Fun vd = VD ( primary ) ;
 1020const LHCb::Particle* B = ... ;
 1030const double dist = vd ( B ) ;

VDCHI2, C++ type LoKi::Particles::VertexChi2Distance

The simple function which evaluates the geometrical distance between the end-vertex of the particle,, and some reference vertex or 3D-point, , in units:
 1000const LHCb::VertexBase* primary = ... ;
 1010Fun chi2d = VDCHI2 ( primary ) ;
 1020const LHCb::Particle* B = ... ;
 1030const double chi2 = chi2d ( B ) ;

VDDOT, C++ type LoKi::Particles::VertexDotDistance

The simple function which evaluates the distance between the end-vertex of the particle,, and some reference vertex or 3D-point, , along the particle momentum :
 1000const LHCb::VertexBase* primary = ... ;
 1010Fun vd = VDDOT ( primary ) ;
 1020const LHCb::Particle* B = ... ;
 1030const double dist = vd ( B ) ;

VDMIN, C++ type LoKi::Particles::MinVertexDistance

The function which evaluates the minimal distance between the end-vertex of the particle,, and the set of the reference vertices or 3D-points: :
 1000CONTAINER primaries = ... ;
 1010Fun fun = VDMIN ( primaries ) ;
 1020const LHCb::Particle* B = ... ;
 1030const double vdMin = fun ( B ) ;

VDMINCHI2, C++ type LoKi::Particles::MinVertexDistance

The function which evaluates the minimal -distance between the end-vertex of the particle,, and the set of the reference vertices or 3D-points: :
 1000CONTAINER primaries = ... ;
 1010Fun fun = VDMINCHI2( primaries ) ;
 1020const LHCb::Particle* B = ... ;
 1030const double minChi2 = fun ( B ) ;

VDSIGN, C++ type LoKi::Particles::VertexSignedDistance

The simple function which evaluates the signed geometrical 3D-distance between the end-vertex of the particle ,, and some reference vertex or 3D-point, , the distance is signed according to the sign of :
 1000const LHCb::VertexBase* primary = ... ;
 1010Fun vd = VDSIGN ( primary ) ;
 1020const LHCb::Particle* B = ... ;
 1030const double dist = vd ( B ) ;

VFASPF, C++ type LoKi::Particles::VFunAsPFun

The adapter function, which applies the vertex function to the end vertex of the given particle:
 1000CONTAINER primaries = ... ;
 1010// get long lived particles with v_z > 20 * cm  
 1020Range londLived = select ( "LongLived" , 20 * cm < VFASPF( VZ ) ) ;

VFUNASPFUN

It is an alias for VFASPF, see VFASPF

W

It is an alias for WEIGHT, see WEIGHT

WEIGHT, the instance of LoKi::Particles::Weight()

The simple function which returns the weight of the particle, LHCb::Particle::weight:
 1000const LHCb::Particle* p = ... ;
 1010const double weight = WEIGHT ( p ) ;

ZERO, the instance of LoKi::Constant<const LHCb::Particle*>(0)

The most trivial function which always returns 0


-- Vanya BELYAEV - 17 Jul 2007

Edit | Attach | Watch | Print version | History: r13 < r12 < r11 < r10 < r9 | Backlinks | Raw View | WYSIWYG | More topic actions
Topic revision: r13 - 2018-12-19 - ChristopherMarkBurr
 
    • Cern Search Icon Cern Search
    • TWiki Search Icon TWiki Search
    • Google Search Icon Google Search

    LHCb All webs login

This site is powered by the TWiki collaboration platform Powered by PerlCopyright & 2008-2019 by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Ideas, requests, problems regarding TWiki? Send feedback