QCD analysis of D-parameter in near-to-planar three-jet events

TL;DR

This work tackles the QCD description of the D-parameter distribution in near-to-planar three-jet $e^+e^-$ events. It develops an all-order perturbative resummation including double- and single-logarithmic terms, matches to exact ${\cal O}(\alpha_s^2)$ matrix elements, and adds leading $1/Q$ non-perturbative corrections via the dispersive approach with the Milan factor. The NP corrections are found to be sizable in this 3-jet context and depend on the event geometry, suggesting higher-order power corrections may be relevant near the peak. The framework enables precision extraction of $\alpha_s(M_Z)$ from multi-jet observables and provides a test of NP universality, with implications for multi-jet dynamics in hadron-hadron collisions.

Abstract

We present the QCD analysis of D-parameter distribution in near-to-planar 3-jet e+e- annihilation events. We derive the all-order resummed perturbative prediction and the leading power suppressed non-perturbative corrections both to the mean value and the distribution. Here non-perturbative corrections are larger than in 2-jet shape observables, so that higher order non-perturbative effects could be relevant. Experimental data (not yet available) are needed in order to cast light on this important point. The technique we develop aims at improving the accuracy of the theoretical description of multi-jet ensembles, in particular in hadron-hadron collisions.