Measurements of Quarkonium Production Cross-Sections with the CMS Experiment

Using large data samples of dimuon events, CMS has performed detailed measurements of differential cross sections of J/$\Psi$, $\Psi$(2S) and $\Upsilon$(nS) states, as a function of transverse momentum in several rapidity bins. The measurements reach significantly higher transverse momentum than previously reported. The quarkonium production cross-sections are compared with recent predictions in the context of NLO nonrelativistic QCD. In this talk, we will present a new measurement on $\Upsilon$(nS) production cross sections in proton-proton collisions at $\sqrt{s}$ = 7 TeV. We report the cross section results integrated over the transverse momentum range $p_{\rm T} <$ 50 GeV/c and rapidity range -2.4 $<y<$ 2.4. We also report the measurement of the $\Upsilon$(nS) differential cross sections as a function of transverse momentum and rapidity and the cross section ratios $\Upsilon$(2S)/$\Upsilon$(1S) and $\Upsilon$(3S)/$\Upsilon$(1S). Finally, we report the very recent measurement of $\chi_{c2}$ / $\chi_{c1}$ production cross-sections, differentially in $p_{\rm T}$, extending to $p_{\rm T}$ = 25 GeV/c, thereby providing an important test of QCD calculations at higher $p_{\rm T}$ than previously possible.