Measurement of colour flow using jet-pull observables in top-quark-antiquark events with the ATLAS experiment at √s = 13 TeV

20 Nov 2019, 09:40
20m
High Multiplicities (small system) High Multiplicities (small system)

Speaker

Reinhild Peters for the ATLAS Collaboration (University of Manchester (GB))

Description

Measurements of distributions of two weighted angular moments derived from jet
constituents are presented. The jet-pull angle and the jet-pull magnitude, both of
which are derived from the jet-pull angular moment, encode the colour connections between
partons that seed the jets.
The measurements are performed in top-quark-antiquark events with one leptonically
decaying W boson and one hadronically decaying W boson, using 36.1 fb-1 of pp collision
data recorded by the ATLAS detector at a centre-of-mass energy of 13 TeV delivered by the
Large Hadron Collider. The observables are measured for two dijet systems, corresponding
to the colour-connected daughters of the W boson and the two b-jets from the top-quark
decays. To allow the comparison of the measured distributions to colour model predictions,
the measured distributions are unfolded to particle level, after correcting for experimental
effects introduced by the detector. While good agreement can be found for some
combinations of predictions and observables, none of the predictions describes the data well
across all observables.
Reference: TOPQ-2017-13,
https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/TOPQ-2017-13/

Presentation Materials