Polarizations of $\chi_{c1}$ and $\chi_{c2}$ in prompt production at the   LHC
  Prompt $\chi_c$ production at hadron colliders may provide a unique test for the color-octet mechanism in nonrelativistic QCD. We present an analysis for the polarization observables of $\chi_{c1}$ and $\chi_{c2}$ at next-to-leading order in $\alpha_S$, and propose to measure them at the LHC, which is expected to be important for testing the validity of NRQCD. 
Hua-Sheng Shao, Yan-Qing Ma, Kai Wang, Kuang-Ta Chao
hep-ph hep-ex