Event Selection: Glossary

POET output files contain the important kinematics, identification, isolation, and tagging information typically needed for analysis event selection.

Event selection criteria must be a reasoned balance of physics objects to keep, physics objects to reject, and trigger options from CMS.

The CMS trigger system filters uninteresting events, keeping the budget high for the flow of interesting data.

Computationally, a trigger is a CMSSW path, which is composed of several software modules.

Trigger prescales allow the data acquisition to adjust to changes in instantaneous luminosity while keeping the rate of incomming data under control

The trigger systems allows for the classification and organization of datasets by physics objects of interest

It is possible to retrieve trigger information from MiniAOD files directly

Trigger objects can be checked against reconstructed objects

A lot more information related to trigger can be obtained from the HLTConfigProvider and HLTPrescaleProvider and the conditions database

Come back for the discussion session after the break!

Triggers usually impose various kinematic restrictions on objects of interest.

Final state objects produced promptly from the proton collision are typically required to have significant momentum, tight ID quality, and to be isolated (depending on the topology of the physics process).

Veto objects are typically selected using looser criteria so that the efficiency of the veto is very high.

Correlations between objects can be used either to select specifically for signal events or reject background events.