Collinearity approximations and kinematic shifts in partonic shower algorithms

TL;DR

This paper investigates how collinearity approximations in partonic shower algorithms cause kinematic shifts in momentum distributions, affecting jet and heavy flavor production predictions at the LHC.

Contribution

It analyzes the impact of collinearity approximations combined with energy-momentum conservation on kinematic distributions in partonic shower algorithms.

Findings

Kinematic shifts occur event by event due to collinearity approximations.

Numerical results show measurable effects in jet and heavy flavor production at the LHC.

Abstract

We study kinematic effects due to the approximation of on-shell, collinear partons in shower Monte Carlo event generators. We observe that the collinearity approximation, combined with the requirements of energy-momentum conservation, gives rise to a kinematic shift, event by event, in longitudinal momentum distributions. We present numerical results in the case of jet and heavy flavor production processes measured at the LHC.