In this paper, we present a new proposal on how to measure quark/gluon jet
properties at the LHC. The measurement strategy takes advantage of the fact
that the LHC has collected data at different energies. Measurements at two or
more energies can be combined to yield distributions of any jet property
separated into quark and gluon jet samples on a statistical basis, without the
need for an independent event-by-event tag. We illustrate our method with a
variety of different angularity observables, and discuss how to narrow down the
search for the most useful observables.Comment: 20 pages, 30 figure