On the universality of hadronisation corrections to QCD jets

TL;DR

<3-5 sentence high-level summary> The paper investigates hadronisation corrections to QCD jets at hadron colliders, focusing on how the jet transverse momentum shift δp_t from non-perturbative effects depends on the jet algorithm. Using a two‑loop dispersive (renormalon) framework, it connects jet‑level power corrections to the LEP event‑shape Milan factor, showing that for kt jets the correction is non‑universal but calculable with a small overall rescaling (~1.01), while for anti‑kt jets the correction matches the universal Milan factor (~1.49). The work clarifies the interplay between 1/R hadronisation corrections and 1/Q event‑shape corrections, and provides a practical method to incorporate non‑perturbative effects into jet observables for LHC phenomenology. It also lays groundwork for extending the analysis to other jet algorithms such as SISCone and Cambridge/Aachen.

Abstract

We improve previously derived analytical estimates of hadronisation corrections to QCD jets at hadron colliders, firmly establishing at the two-loop level the link to the well-known power corrections to LEP event-shape variables. The results of this paper apply to jets defined in the kt and anti-kt algorithms but the general framework presented here holds also for other algorithms for which calculations are in progress.