Merging parton showers and matrix elements -- back to basics

Nils Lavesson, Leif Lönnblad

    Research output: Contribution to journalArticlepeer-review

    Abstract

    We make a thorough comparison between different schemes of merging fixed-order tree-level matrix element generators with parton-shower models. We use the most basic benchmark of the O(alpha_S) correction to e+e- -> jets, where the simple kinematics allows us to study in detail the transition between the matrix-element and parton-shower regions. We find that the CKKW-based schemes give a reasonably smooth transition between these regions, although problems may occur if the parton shower used is not ordered in transverse momentum. However, the so-called Pseudo-Shower and MLM schemes turn out to have potentially serious problems due to different scale definitions in different regions of phase space, and due to sensitivity to the details in the initial conditions of the parton shower programs used.
    Original languageEnglish
    JournalJournal of High Energy Physics
    Volume4
    Issue number85
    DOIs
    Publication statusPublished - 2008

    Subject classification (UKÄ)

    • Subatomic Physics

    Free keywords

    • Phenomenological Models
    • Jets
    • Parton Model
    • QCD

    Fingerprint

    Dive into the research topics of 'Merging parton showers and matrix elements -- back to basics'. Together they form a unique fingerprint.

    Cite this