11th International Conference on Hard and Electromagnetic Probes of High-Energy Nuclear Collisions

The ALICE experiment at the LHC investigates the properties of the hot and dense nuclear matter created in heavy-ion collisions. By comparing the particle production in pp and p--Pb collisions, possible nuclear initial state effects can be isolated. Measurements of the $\omega$ meson $p_\text{T}$-spectra in pp and p--Pb collisions not only allow for a determination of the nuclear modification factor $R_\text{pA}$, but also provide insights into the fragmentation process and serve as vital input for direct photon cocktail simulations.

The $\omega$ mesons can be reconstructed in ALICE via their primary decay channel into three pions ($\omega\rightarrow\pi^+\pi^-\pi^0$). While the two charged pions are being directly identified by the tracking detectors, i.e. the Time Projection Chamber and the Inner Tracking System, the $\pi^0$ is reconstructed from its two decay photons. These photons can either be detected in the calorimeters or via tracks in case they convert to an electron-positron pair in the detector material.

In this poster, the measurement of the $\omega$ meson production in pp and p--Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02~$TeV will be presented. This includes the signal extraction and various corrections of the $\omega$ meson yields, as well as comparisons to theory calculations.