Production of $\pi^{0}$, $K^{\pm}$ and $\eta$ mesons in Pb-Pb and pp collisions at $\sqrt{s_{\rm NN}}=$2.76 TeV measured with the ALICE detector at the LHC

TL;DR

This paper reports measurements of neutral mesons and kaons in Pb-Pb and pp collisions at 2.76 TeV, providing insights into quark-gluon plasma effects like jet quenching and collective behavior through transverse momentum spectra and particle ratios.

Contribution

First comprehensive measurement of $ m \pi^{0}$, $K^{ m \pm}$, and $ m \eta$ mesons in Pb-Pb and pp collisions at 2.76 TeV with detailed spectra and particle ratios from the ALICE experiment.

Findings

Observation of meson suppression at high $p_{T}$ in Pb-Pb collisions.

Measurement of particle ratios $ m \eta/ m \pi^{0}$ and $K^{ m \pm}/ m \pi^{ m \pm}$.

Comparison with theoretical models of jet quenching and collective effects.

Abstract

One of the key signatures of the Quark-Gluon Plasma (QGP) is the modification of hadron transverse momentum differential cross-sections in heavy-ion collisions (HIC) as compared to proton-proton (pp) collisions. Suppression of hadron production at high transverse momenta ($p_{\rm T}$) in HIC has been explained by the energy loss of the partons produced in the hard scattering processes which traverse the deconfined quantum chromodynamic (QCD) matter. The dependence of the observed suppression on the $p_{\rm T}$ of the measured hadron towards higher $p_{\rm T}$ is an important input for the theoretical understanding of jet quenching effects in the QGP and the nature of the energy loss, while suppression towards lower $p_{\rm T}$ gives information about collective behaviour. The ALICE experiment at the Large Hadron Collider (LHC) performs a variety of measurements including the spectra of neutral mesons and kaons at mid-rapidity in a wide $p_{\rm T}$ range in pp, p-Pb and Pb-Pb collisions. An overview of ALICE results in HIC and pp collisions at $\sqrt{s_{NN}}=$2.76 TeV of neutral pions, kaons and eta mesons as a function of transverse momentum ($p_{\rm T}$) and centrality will be presented. Ratios $\eta$/$\pi^{0}$, $K^{\pm}$/$\pi^{\pm}$ as well as comparisons to model calculations will also be discussed.