The European Physical Journal C | |
Importance of a consistent choice of αS in the matching of AlpGen and Pythia | |
B. Cooper1  J. Katzy2  L. Mijović3  M. L. Mangano4  A. Messina4  P. Skands4  | |
[1] Department of Physics & Astronomy, University College London, WC1E 6BT, London, UK;Deutsches Electron Synchroton, 22603, Hamburg, Germany;Deutsches Electron Synchroton, 22603, Hamburg, Germany;CEA-Saclay, IRFU/SPP, bât. 141, 91191, Gif sur Yvette Cedex, France;European Organization for Nuclear Research, CERN, 1211, Geneva 23, Switzerland; | |
关键词: Large Hadron Collider; Monte Carlo; Partonic Shower; Initial State Radiation; Monte Carlo Prediction; | |
DOI : 10.1140/epjc/s10052-012-2078-y | |
来源: Springer | |
【 摘 要 】
We consider the impact of varying αs choices (and scales) on each side of the so-called “matching scale” in MLM-matched matrix-element + parton-shower predictions of collider observables. We explain how inconsistent prescriptions can lead to counter-intuitive results and present a few explicit examples, focusing mostly on W/Z+jets processes. We give a specific prescription for how to improve the consistency of the matching and also address how to perform consistent tune variations (e.g., of the renormalization scale) around a central choice. Comparisons to several collider processes are included to illustrate the properties of the resulting improved matching, relying on AlpGen + Pythia 6, with the latter using the so-called Perugia 2011 tunes, developed as part of this effort. Our observations, nevertheless, apply to the large class of tools where matrix-element generators are merged with independent codes for the parton-shower evolution.
【 授权许可】
CC BY
【 预 览 】
Files | Size | Format | View |
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RO202112163422920ZK.pdf | 1208KB | download |