The production of Quarkonium is an important testing ground for QCD calculations. The J/$\psi$ and $\Upsilon$(1S) production cross-sections are measured in proton-proton collisions at the ATLAS detector at the LHC. Differential cross sections as a function of transverse momentum and rapidity have been measured. Charmonium states $\chi_{c1}$(1P) and $\chi_{c2}$(1P) have been observed through radiative decays, as well as a new $\chi_{b}$ state. Results are compared to perturbative QCD predictions.

Proc. of DIS 2012, 873 - 876; DESY-PROC-2012-02; ISSN 1435-8077