Speaker
Description
The ALICE experiment is dedicated to study the properties of the Quark-Gluon Plasma (QGP) which is expected to be formed in ultra-relativistic heavy ion collisions. Measurements of hadron production in pp and p-Pb collisions are of importance to understand the properties of this hot and dense medium. In pp collisions, meson spectra serve as a reference for heavy-ion collisions and add constrains to theoretical calculations such as NLO pQCD. In p-Pb, measurements of hadron spectra serve as reference to help disectangle initial and final-state effects for the hadron suppression observed at intermediate $p_T$ in Pb-Pb collisions. Moreover, the measurement of neutral mesons ($\pi^{0}$ and $\eta$) is important to estimate the background in the direct photon analysis. ALICE has measured $\pi^{0}$ and $\eta$ mesons via their two photon decay channel $\pi^{0}\rightarrow\gamma\gamma$ and $\eta\rightarrow\gamma\gamma$ and in the case of $\pi^{0}$ in p-Pb collisions also via its Dalitz decay channel $\pi^{0}\rightarrow\gamma^{*}\gamma\rightarrow e^+e^-\gamma$. Photons were measured by electromagnetic calorimeters, PHOS and EMCal, and by their conversions into $e^+e^-$ in the central barrel using the TPC and ITS detectors.
In this talk, the measurement of the $\pi^{0}$ and $\eta$ mesons in pp and p-Pb collisions will be presented and compared to theoretical model calculations. The nuclear modification factor $R_{p-Pb}$ will also be presented.
