Production of $\chi_c$- and $\chi_b$-mesons in high energy hadronic   collisions
  This paper is devoted to phenomenological study of $\chi_{c,b}$-mesons production in high energy hadronic collisions in the framework of NRQCD. We analyze all available experimental data on $\chi_c$-mesons production and extract non-perturbative NRQCD matrix elements from fitting the data. We show, that measured $p_T$-spectrum of $\chi_c$-mesons is mainly formed by color singlet components, while $\sigma(\chi_{c2})/\sigma(\chi_{c1})$ ratio depends strongly on color octet matrix elements; this ratio becomes a highly sensitive tool to study contribution of different terms from the NRQCD expansion. Obtained using NRQCD scaling rules predictions for $\chi_b$-mesons cross sections are also given. 
A. K. Likhoded, A. V. Luchinsky, S. V. Poslavsky
hep-ph