Tagging $q/g$ and $g\rightarrow b\bar{b}$ Jets at ATLAS

We present first results on jet tagging in ATLAS. First, we present the results of an implementation of a quark/gluon tagger built with tracking variables, and show that strong gluon rejection is possible even in high luminosity environments. We use template methods to validate the quark/gluon tagger in data. Second, we present results on a new technique developed to identify jets originating from a gluon that has split to $b\bar{b}$. Jet substructure variables enable high levels of double $b\bar{b}$-jet rejection. The ability to separate quark from gluon jets and single $b$-jets from gluons splitting to $b\bar{b}$-jets can enhance the LHC discovery potential by rejecting gluon-dominated backgrounds.