Journal of High Energy Physics

, 2018:118 | Cite as

Momentum conservation and unitarity in parton showers and NLL resummation

  • Stefan Höche
  • Daniel Reichelt
  • Frank Siegert
Open Access
Regular Article - Theoretical Physics


We present a systematic study of differences between NLL resummation and parton showers. We first construct a Markovian Monte-Carlo algorithm for resummation of additive observables in electron-positron annihilation. Approximations intrinsic to the pure NLL result are then removed, in order to obtain a traditional, momentum and probability conserving parton shower based on the coherent branching formalism. The impact of each approximation is studied, and an overall comparison is made between the parton shower and pure NLL resummation. Differences compared to modern parton-shower algorithms formulated in terms of color dipoles are analyzed.


QCD Phenomenology 


Open Access

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Copyright information

© The Author(s) 2018

Authors and Affiliations

  1. 1.SLAC National Accelerator LaboratoryMenlo ParkU.S.A.
  2. 2.Institut für Kern- und TeilchenphysikTechnische Universität DresdenDresdenGermany

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