This page lists the basic (charged) Particle Identification (PID) lists produced at run-time. The PID lists consist of particles that pass a given PID selector. Each PID selector uses a number of PID variables to accept or reject a given track. The variables used for each type of particle are listed in the tables. Currently, the PID group provides several different types of PID selector:

__Cut-based__selectors impose simple cuts on the PID variables. Different levels of selector - Loose, Tight, and so on - correspond to looser or tighter sets of cuts.__Likelihbood__selectors use the PID variables to compute Likelihood functions for different particle ID hypotheses. Different levels of selector correspond to tighter or looser cuts on the Likelihood functions. For example, the kaon likelihood selector requires that the likelihood for kaons be higher than the likelihood for pions.__Global likelihood selectors__- Coming soon.__Neural network__selectors use the PID variables as inputs to a neural network algorithm. Neural networks predict outcomes based on a large sample of previous examples. For PID, this means that they are given examples of how PID variables behave for different particles, and optimize the selection based on this training.__Roy selectors__- No longer in use.

The PID lists are produced by the BetaPid package.

For more information and detailed documentation of each selector, see the PID homepage, in particular the PID selectors documentation page.

## Electrons | |

Variable |
Description |

E/p | Ratio of energy deposited in the calorimeter, to track momentum. |

Ncry | Number of EMC crystals hit |

LAT | Lateral energy distribution |

A42 | Zernike moment |

dE/dx | Energy loss in the DCH |

theta_c | Cerenkov angle in the DRC |

N_gamma | Number of photons in DRC |

N_gamma_exp | Number of photons expected |

Delta_phi | Track-bump separation |

Selector Type |
Lists |

Cut-based ("Micro") |
eMicroNoCal eMicroVeryLoose eMicroLoose eMicroTight eMicroVeryTight |

Likelihood ("LH") | PidLHElectrons |

Roy ("Roy") |
eRoyLoose |

## Muons | |

Variable |
Description |

Ecand | Energy released in the EMC. |

NL | Number of IF hit layers in a cluster |

Lambda_meas | Measured number of interaction lengths traversed. |

Delta_Lambda | Difference between the expected (for muons) and measured number of interaction lengths traversed.. |

chi2fit | chi2/dof of IFR hit strips in a polynomial fit of the cluster. |

chi2mat | chi2/dof of the IFR hit strips in the track extrapolation. |

Tc | Track continuity. |

m and sigma_m | Average multiplicity of hit strips per layer, and its standard deviation. |

Selector Type |
Lists |

Cut-based ("Micro") |
muMicroMinimumIonizing
muMicroVeryLoose muMicroLoose muMicroTight muMicroVeryTight |

Neural Net |
muNNVeryLoose muNNLoose muNNTight muNNVeryTight muNNVeryLooseFakeRate muNNLooseFakeRate muNNTightFakeRate muNNVeryTightFakeRate |

Likelihood |
muLikeVeryLoose muLikeLoose muLikeTight |

## Kaons | |

Variable |
Description |

dE/dx | Energy loss in the SVT and DCH |

theta_c | Cerenkov angle in the DRC |

N_gamma | Number of photons in DRC |

N_gamma_exp | Number of photons expected |

Selector Type |
Lists |

Neural Network ("Micro") |
KMicroVeryLoose KMicroLoose KMicroTight KMicroVeryTight KMicroNotPion KMicroNotPionGTL |

Roy ("Roy") |
KRoyLoose KRoyDefault KRoyNotPion KRoyNotPionOrUnknown |

Simple (K-ID cut only) |
KSimpleLoose KSimpleTight |

Neural Network |
KNNVeryLoose KNNLoose KNNTight KNNVeryTight KNNNotPion |

Likelihood |
KLHNotPion
KLHVeryLoose KLHLoose KLHTight KLHVeryTight KLHNotPionGTL KGLHTight |

## Pions | |

Variable |
Description |

dE/dx | Energy loss in the SVT and DCH |

theta_c | Cerenkov angle in the DRC |

N_gamma | Number of photons in DRC |

TrkQual | Track quality |

iselectron | Whether the track passes the LH electron selector |

ismuon | Whether the track passes the MicroVeryTight muon selector |

Selector Type |
Lists |

Likelihood ("LH") |
piLHVeryLoose piLHLoose piLHTight piLHVeryTight piGLHTight |

Roy ("Roy") |
piRoyLoose piRoyNotKaon |

## Protons | |

Variable |
Description |

dE/dx | Energy loss in the SVT and DCH |

theta_c | Cerenkov angle in the DRC |

N_gamma | Number of photons in DRC |

TrkQual | Track quality |

iselectron | Whether the track passes the LH electron selector |

ismuon | Whether the track passes the MicroVeryTight muon selector |

Selector Type |
Lists |

Likelihood ("LH") |
pLHVeryLoose pLHLoose pLHTight pLHVeryTight pGLHTight |

## PID SubLists (SmpPidRefineProdSequence.tcl)Candidate must be a member of BOTH lists. | |

muNNTightGTL | muNNTight GoodTracksLoose |

PidLHElectronsGTL |
PidLHElectrons GoodTracksLoose |

piLHLooseGTVL |
piLHLoose GoodTracksVeryLoose |

piLHLooseGTL |
piLHLoose GoodTracksLoose |

muNotEl | mNNTight NOT eLHBremAndGTL |

eLooseNoCal |
eMicroNoCal eMicroLoose |

eOrMuBremAndGTL |
muNotEl eLHBremAndGTL |