Measurement of jets and photons with the ALICE experiment at the LHC

TL;DR

This paper reports measurements of jets and photons in heavy-ion collisions at the LHC, revealing jet quenching and thermal photon emission, which provide insights into the properties of the Quark-Gluon Plasma.

Contribution

It presents new experimental results on jet quenching and photon production in Pb-Pb and p-Pb collisions, enhancing understanding of QGP characteristics.

Findings

Jets are collimated in Pb-Pb collisions.

High transverse momentum hadron yields are strongly suppressed.

Photons do not show suppression and exhibit thermal emission at low momentum.

Abstract

Jets and direct photons are used to probe the formation and the properties of the Quark-Gluon Plasma (QGP) by the ALICE Collaboration. The results shown here will present the measurements obtained from Pb$-$Pb and p$-$Pb collisions. It is observed that in Pb$-$Pb collisions jets are collimated and hadron yields ($\pi^{0}$ and $\eta$) at high transverse momentum undergo strong suppression due to the interaction of the patrons with the QGP. On the other hand, photons do not show any suppression in this region, and, in addition, an excess attributed to a thermal emission is observed at low transverse momentum. No hints of medium modifications are observed for the p$-$Pb results, for which a jet quenching limit of $-$0.4 GeV/$c$ is calculated.