Reliability of three-jet power-correction variations

Determine whether the range of variations used for the three-jet power-correction function provides a reliable estimate of the associated uncertainty in thrust fits based on the Caola–et al. model and the restricted fit window of Benitez–et al.

Background

The paper discusses the breakdown of the leading-power dijet approximation at larger thrust values, where non-perturbative effects depend on the multi-jet geometry and are represented by a thrust-dependent function such as ζ(τ). Several phenomenological models have been proposed, but the authors emphasize that a first-principles calculation of this function in full QCD is not currently available.

For the restricted thrust fit window considered in the cited Benitez et al. analysis, the dominant three-jet correction may be largely absorbed into the fitted non-perturbative parameter Ω₁, producing only a small shift in α_s. However, the adequacy of the model variations used to quantify the remaining uncertainty has not been established.