Abstract
Distributions sensitive to the underlying event in QCD jet events have been measured with the ATLAS detector at the LHC, based on of proton-proton collision data collected at a centre-of-mass energy of 7 . Charged-particle mean and densities of all-particle and charged-particle multiplicity and have been measured in regions azimuthally transverse to the hardest jet in each event. These are presented both as one-dimensional distributions and with their mean values as functions of the leading-jet transverse momentum from 20 to 800 . The correlation of charged-particle mean with charged-particle multiplicity is also studied, and the densities include the forward rapidity region; these features provide extra data constraints for Monte Carlo modelling of colour reconnection and beam-remnant effects respectively. For the first time, underlying event observables have been computed separately for inclusive jet and exclusive dijet event selections, allowing more detailed study of the interplay of multiple partonic scattering and QCD radiation contributions to the underlying event. Comparisons to the predictions of different Monte Carlo models show a need for further model tuning, but the standard approach is found to generally reproduce the features of the underlying event in both types of event selection.
Item Type: | Journal article |
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Form of publication: | Publisher's Version |
Faculties: | Physics |
Subjects: | 500 Science > 530 Physics |
URN: | urn:nbn:de:bvb:19-epub-24280-4 |
ISSN: | 1434-6044 |
Alliance/National Licence: | This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively. |
Annotation: | SCOAP3-Publikation. - Weitere Autoren siehe PDF-Volltext |
Language: | English |
Item ID: | 24280 |
Date Deposited: | 01. Jul 2015, 10:46 |
Last Modified: | 08. May 2024, 08:31 |