Probing charmonium production through jet substructure at ATLAS

There are many open questions regarding charmonium production at hadron colliders. The color octet production mechanism of non-relativistic QCD (NRQCD) was introduced in order to describe the $p_T$ spectrum of prompt $J/\psi$ particles. This mechanism is expected to be characterized by enhanced hadronic activity around the $J/\psi$. Recently it has been suggested that jet substructure techniques may be able to discriminate between the octet and singlet production mechanisms. An ATLAS measurement of N-subjettiness and the $J/\psi$-jet momentum fraction in 8 TeV LHC proton-proton collisions will be described.