Jet acoplanarity via hadron+jet measurements in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}} = 5.02$ TeV with ALICE

Abstract

We present the first fully-corrected semi-inclusive distribution of charged jets recoiling from a trigger hadron in 0-10% Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV as a function of the azimuthal angle between the trigger hadron and jet, $\Delta\varphi$. This technique provides a precise data-driven subtraction of the large uncorrelated background contaminating the measurement, and enables the exploration of jet acoplanarity. Results for $R=0.2$ recoil jets in the region $30 < p_{\mathrm{T,jet}}^{\mathrm{ch}} < 40~\mathrm{GeV}/c$ are shown, where a suppression and narrowing of the $\Delta\varphi$ distribution is observed in 0-10% Pb-Pb collisions with respect to a PYTHIA pp reference.