ATLAS reach for Quarkonium production and polarization measurements

The ATLAS detector at CERN's LHC is preparing to take data from the first proton-proton collisions expected in the next few months. We report on the analysis of simulated data samples for production of heavy Quarkonium states J / ψ and ϒ, corresponding to an integrated luminosity of 10 p b − 1 with center of mass energy of 14 TeV expected at the early ATLAS data. We review various aspects of prompt Quarkonium production at LHC: the accessible ranges in transverse momentum and pseudorapidity, spin alignment of vector states, separation of color octet and color singlet production mechanism and feasibility of observing radiative decays χ c and χ b decays. Strategies of various measurements are outlined and methods of separating promptly produced J / ψ and ϒ mesons from various backgrounds are discussed.