Neutral pion and $\eta$ meson production at mid-rapidity in Pb-Pb collisions at $\sqrt{s_{NN}}$ = 2.76 TeV
Phys.Rev., 2018.
The collaboration

Abstract (data abstract)
CERN-LHC. Neutral pion and $\eta$ meson production in the transverse momentum range 1 $< p_{\rm T} <$ 20 GeV/$c$ have been measured at midrapidity by the ALICE experiment at the Large Hadron Collider (LHC) in central and semi-central Pb-Pb collisions at $\sqrt{s_{\rm NN}}$ = 2.76 TeV. These results extend the $p_{\rm T}$ reach of the previous ALICE PI0 measurements from 12 GeV/$c$ to 20 GeV/$c$ and present the first measurement of the ETA meson in heavy-ion collisions at the LHC. The $\eta$ to $\pi^{0}$ ratio is similar for the two centralities and reaches a plateau value of 0.457 $\pm$ 0.013$^{stat}$ $\pm$ 0.018$^{syst}$. A suppression of the same magnitude for $\pi^{0}$ and $\eta$ meson production is observed in Pb-Pb collisions with respect to their production in pp collisions scaled by the number of binary nucleon-nucleon collisions. For both mesons, the nuclear modification factor $R_{\rm AA}$ reaches a minimum at $p_{\rm T} \approx$ 7 GeV/$c$ and then increases with transverse momentum. The measurements show a stronger suppression with respect to what was observed at lower center-of-mass energies in the $p_{\rm T}$ range 6 $< p_{\rm T} <$ 10 GeV/$c$. The results are compared with statistical hadronization models at low-$p_{\rm T}$ and with NLO pQCD jet quenching predictions at high-$p_{\rm T}$.