Better jet clustering algorithms

Abstract

We investigate modifications to the k ⊥ -clustering jet algorithm which preserve the advantages of the original Durham algorithm while reducing non-perturbative corrections and providing better resolution of jet substructure. We find that a simple change in the sequence of clustering (combining smaller-angle pairs first), together with the 'freezing' of soft resolved jets, has beneficial effects.

QCD Matrix Elements + Parton Showers

“…energy of 189 GeV, defined here by the Cambridge algorithm [28], are displayed in figure 9. They demonstrate that APACIC++ extrapolates correctly to higher energies with all parameters fixed at the Z-pole.…”

Event shapes in e+e annihilation and deep inelastic scattering

“…(26) and (27), but that is relevant for all 3-jet studies is that the power correction acquires a dependence on C A , i.e. there is sensitivity to hadronisation from a gluon.…”

“…(27) for the shift to the shoulder; however the analysis [89] doesn't take into account resummation effects at the shoulder which may also contribute to an effective shift. A first analysis of corrections to the y 3 distribution has been given in [109] which shows evidence for 1/Q 2 contributions in the y 3 distribution at the two lowest JADE centre of mass energies (14 and 22 GeV).…”

Novel subjet observables for jet quenching in heavy-ion collisions

“…To investigate the dependence of the proposed observable and its sensitivity to the effects of jet quenching we varied the subjet reconstruction algorithm as well as the subjet radius parameter R sj < R. We find no significant differences in ΔS 12 subjet distributions when changing the clustering algorithm from anti-k T [40] to k T [54] or Cambridge-Achen (C/A) [55]. However, ΔR subjet depends, by construction, on the reconstruction algorithm.…”