  As most target final states for searches and measurements at the Large Hadron
Collider have a particular quark/gluon composition, tools for distinguishing
quark- from gluon-initiated jets can be very powerful. In addition to the
difficulty of the classification task, quark-versus-gluon jet tagging is
challenging to calibrate. The difficulty arises from the topology dependence of
quark-versus-gluon jet tagging: since quarks and gluons have net quantum
chromodynamic color charge while only colorless hadrons are measured, the
radiation pattern inside a jet of a particular type depends on the rest of its
environment. Given a definition of a quark or gluon jet, this paper studies the
topology dependence of such jets in simulation. A set of phase space regions
and jet substructure observables are identified for further comparative studies
between generators and eventually in data.
