Jet overlap in heavy ion collisions at energies available at the CERN Large Hadron Collider and its consequences for the jet shape

Abstract

Central lead-lead collisions at the LHC energies may pose a particular challenge for jet identification as multiple jets are produced per each collision event. We simulate the jet evolution in central Pb-Pb events at √ sNN = 2.76 GeV collision energy with EPOS3 initial state, which typically contains multiple hard scatterings in each event. Therefore the partons from different jets have a significant chance to overlap in momentum space. We find that 30% of the jets with p ⊥ > 50 GeV, identified by the standard anti-k ⊥ jet finding algorithm with jet cone size R=0.3, contain 'intruder' particles from overlapping generator-level jets. This fraction increases with increasing beam energy and increasing R. The reconstructed momentum of the jet differs from that of the modelled jet by the loss due to jet partons which are outside of the jet cone and by the gain due to intruder partons. The sum of both may be positive or negative. These intruder partons particularly affect the radial jet momentum distribution because they contribute mostly at large angles ∆r with respect to the jet centre. The study stresses the importance of the jet overlap effect emerging in central lead-lead collisions at the LHC energes, while being negligible in peripheral PbPb or pPb/pp collisions.

Placement of Infrastructure for Urban Electromobility: A Sustainable Approach

“…The municipality is divided into ninety-six districts (Figure 2b), which are the city's smallest administrative spatial units. According to the Brazilian National Traffic Department [49], the Brazilian fleet comprised 100,746,553 motor vehicles (automobiles, motorcycles, buses, trucks, etc.) in December 2018.…”

“…São Paulo city had 8,861,208 motor vehicles, and 0.02% of them were electric vehicles (about 1800 units). According to the Brazilian National Traffic Department [49], the Brazilian fleet comprised 100,746,553 motor vehicles (automobiles, motorcycles, buses, trucks, etc.) in December 2018.…”