Azimuthal anisotropy of charged jet production in \(\sqrt{s_{\rm NN}}=2.76\) TeV Pb–Pb collisions

Abstract

This paper presents measurements of the azimuthal dependence of charged jet production in central and semi-central \(\sqrt{s_{\rm NN}}=2.76\) TeV Pb–Pb collisions with respect to the second harmonic event plane, quantified as \(v_2^{\rm ch. jet}\), Jet finding is performed employing the anti-\(k_{\rm T}\) algorithm with a resolution parameter R = 0.2 using charged tracks from the ALICE tracking system. The contribution of the azimuthal anisotropy of the underlying event is taken into account event-by-event. The remaining (statistical) region-to-region fluctuations are removed on an ensemble basis by unfolding the jet spectra for different event plane orientations independently. Significant non-zero \(v_2^{\rm ch. jet}\) is observed in semi-central collisions (30–50% centrality) for \(20<p_{\rm T, ch}^{\rm jet}< 90\) GeV/\(c\), The azimuthal dependence of the charged jet production is similar to the dependence observed for jets comprising both charged and neutral fragments, and compatible with measurements of the \(v_2\) of single charged particles at high \(p_{\rm T}\), Good agreement between the data and predictions from JEWEL, an event generator simulating parton shower evolution in the presence of a dense QCD medium, is found in semi-central collisions.