Production of heavy quarkonia in hadronic experiments

The phenomenology of the production of P-wave chi (c,b) mesons and S-wave eta (c,b) mesons in highenergy hadron-hadron collisions was studied on the basis of nonrelativistic quantum chromodynamics (NRQCD). Available experimental data on chi (c) -meson production were analyzed, and nonperturbative NRQCDmatrix elements were determined from a fit to these data. It is shown that the observed transversemomentum (pT) spectrum of chi (c) mesons is basically formed by color-singlet contributions. At the same time, the ratio sigma(chi (c2))/sigma(chi (c1)) depends greatly on color-octet contributions; this ratio therefore becomes a highly sensitive tool for separating different NRQCD contributions. Predictions for chi (b) -meson production are obtained on the basis of NRQCD scaling rules. For the case of eta (c) -meson production, it is shown that the observed cross sections agree with the color-singlet model featuring phenomenological parameters.