Speaker
Description
The ALICE experiment at the LHC studies the quark-gluon plasma (QGP), a state of matter formed at extreme temperatures/densities with partonic degrees of freedom produced in ultra-relativistic heavy-ion collisions. Jets, generated in the initial hard scatterings, are valuable for probing QGP properties. As they traverse through the QGP medium, their energy and structure are modified by medium interactions.
This presentation shows the measurement of jets recoiling from a high-$p_T$ trigger hadron (h+jets) in central Pb-Pb collisions at $\sqrt{s_{NN}}$ = 5.02 TeV. Jet measurements in heavy-ion collisions are challenging due to the large uncorrelated background, particularly at low transverse momentum ($p_T$). To address this, a novel mixed-event technique is applied, where artificial events with uncorrelated tracks are constructed from real events. Jet reconstruction is performed using the anti-$k_T$ algorithm with varying jet radii and a trigger of $20\,\text{GeV/c}<p_T^{trig}<50\,\text{GeV/c}$. For both real and mixed events, the same analysis is performed, and the jet $p_T$ distribution obtained from the mixed events is used to correct the background yield in real event jet spectra. Finally, an unfolding procedure corrects detector and background effects. This work presents first results of hadron-triggered recoil-jet transverse momentum spectra using the mixed-event technique in ALICE.