Measurement of ω meson production in pp and p -Pb collisions at sNN=5.02 TeV

We present the measurement of the pT-differential production cross section of ω mesons in and p-Pb collisions at sNN=5.02 TeV at midrapidity by ALICE. In addition, the first measurement of the nuclear modification factor RpPb for ω mesons at LHC energies is presented, complementing the existing measurements of lighter neutral mesons such as the π0 and η. Within the measured pT range, the RpPb of ω mesons is compatible with no cold nuclear matter effects within the uncertainties, consistent with previous measurements at lower energies. The ω/π0 ratio is presented for both collision systems, showing no collision system dependence within the uncertainties. The comparison to previously published ω/π0 ratios at lower and higher collision energies in collisions suggests a decreasing trend of the ratio above pT = 4 GeV/c with increasing collision energy. The data in both collision systems are compared to predictions from PYTHIA 8, EPOS LHC, and DPMJET event generators, revealing significant shortcomings in these models’ ability to describe the production of ω mesons.