A Cone Jet-Finding Algorithm for Heavy-Ion Collisions at LHC Energies

Blyth, S-L; Horner, M J; Awes, T; Cormier, T; Gray, H; Klay, J L; Klein, S R; van Leeuwen, M; Morsch, A; Odyniec, G; Pavlinov, A

A Cone Jet-Finding Algorithm for Heavy-Ion Collisions at LHC Energies

Authors

Description

Standard jet finding techniques used in elementary particle collisions have not been successful in the high track density of heavy-ion collisions. This paper describes a modified cone-type jet finding algorithm developed for the complex environment of heavy-ion collisions. The primary modification to the algorithm is the evaluation and subtraction of the large background energy, arising from uncorrelated soft hadrons, in each collision. A detailed analysis of the background energy and its event-by-event fluctuations has been performed on simulated data, and a method developed to estimate the background energy inside the jet cone from the measured energy outside the cone on an event-by-event basis. The algorithm has been tested using Monte-Carlo simulations of Pb+Pb collisions at $\sqrt{s}=5.5$ TeV for the ALICE detector at the LHC. The algorithm can reconstruct jets with a transverse energy of 50 GeV and above with an energy resolution of $\sim30%$.
13 pages, 7 figures