Jet-quenching studies in ultrarelativistic copper-gold nuclei collisions using omega mesons

Nuclear physics

In the paper, the measurement data on ω meson invariant transverse momentum spectra and nuclear modification factors in collisions of copper and gold nuclei (Cu + Au) at energy of 200 GeV have been presented. The studies were conducted with PHENIX spectrometer at RHIC. The obtained ω meson nuclear modification factors were equal (within the uncertainties) to ones derived for π0, η and KS  mesons and for jets as well in the same collision system. The integrated ω-meson nuclear modification factors versus the numbers of nuclei taking part in the nuclei-nuclei interaction, were in agreement (within uncertainties) with the similar dependencies for Cu + Au, Au + Au and Cu + Cu collisions at energy of 200 GeV. The analysis of results suggested that the jet-quenching effect was independent (or weakly dependent) of the shape of a nuclear overlap region realized in these systems.