Longitudinal momentum shifts, showering and nonperturbative corrections in matched NLO-shower event generators

TL;DR

This paper analyzes how nonperturbative effects and parton showering influence collider event predictions, proposing alternative correction methods for NLO event generators to improve agreement with experimental data.

Contribution

It introduces new approaches to incorporate nonperturbative effects and showering corrections in NLO event generators, addressing current limitations.

Findings

Significant parton-showering corrections to jet transverse energy spectra at high rapidity.

Kinematic shifts in longitudinal momentum distributions due to initial state showering.

Implications for jet and heavy mass production predictions at the LHC.

Abstract

Comparisons of experimental data with theoretical predictions for collider processes containing hadronic jets rely on shower Monte Carlo event generators to include corrections to perturbative calculations from hadronization, parton showering, multiple parton collisions. We examine current treatments of these corrections and propose alternative methods to take into account nonperturbative effects and parton showering in the context of next-to-leading-order (NLO) event generators. We point out sizeable parton-showering corrections to jet transverse energy spectra at high rapidity, and discuss kinematic shifts in longitudinal momentum distributions from initial state showering in the case both of jet production and of heavy mass production at the Large Hadron Collider.