Distinguishing between quark and gluon jets How do experimentalists at the LHC differentiate between jets produced by quarks and those produced by gluons. I know that for b quarks there is a b-tagging method, but what do they do for the others in order to separate them from gluon induced jets?
 A: I found a good paper here titled Distinguishing quark and gluon jets at the LHC from CERN's website that answers your question. The introduction states
"Partons emitted from hard scattering process at the LHC form, due to QCD confinement and
hadronization process, hadronic jets, which can be revealed with tracking and calorimeter systems. As known from theoretical principles and from experimental measurements, reconstructed jets show
different properties depending on flavor of original parton. In general, due to the large color factor
of gluons, gluon-initiated jets have higher particle multiplicity, a softer fragmentation function, and
are less collimated than quark-initiated jets. These differences can be exploited to tag jets, and
such a capability plays a fundamental role in several physics analyses. It results in an increased
ability to discriminate full-hadronic final searches - composed mainly by quark-originated jets, from
QCD background - where the gluon component is predominant".
