Measurement of event-shape observables in Z -> l(+)l(-) events in pp collisions at root s=7 TeV with the ATLAS detector at the LHC
2016 (English)In: European Physical Journal C, ISSN 1434-6044, E-ISSN 1434-6052, Vol. 76, no 7, 375Article in journal (Refereed) Published
Event-shape observables measured using charged particles in inclusive Z-boson events are presented, using the electron and muon decay modes of the Z bosons. The measurements are based on an integrated luminosity of 1.1 fb(-1) of proton-proton collisions recorded by the ATLAS detector at the LHC at a centre-of-mass energy root s = 7 TeV. Charged-particle distributions, excluding the lepton-antilepton pair from the Z-boson decay, are measured in different ranges of transverse momentum of the Z boson. Distributions include multiplicity, scalar sum of transverse momenta, beam thrust, transverse thrust, spherocity, and F-parameter, which are in particular sensitive to properties of the underlying event at small values of the Z-boson transverse momentum. The measured observables are compared with predictions from PYTHIA 8, Sherpa, and HERWIG 7. Typically, all three Monte Carlo generators provide predictions that are in better agreement with the data at high Z-boson transverse momenta than at low Z-boson transverse momenta, and for the observables that are less sensitive to the number of charged particles in the event.
Place, publisher, year, edition, pages
2016. Vol. 76, no 7, 375
IdentifiersURN: urn:nbn:se:kth:diva-194086DOI: 10.1140/epjc/s10052-016-4176-8ISI: 000379351100001ScopusID: 2-s2.0-84978517992OAI: oai:DiVA.org:kth-194086DiVA: diva2:1037393
FunderSwedish Research Council
QC 201610142016-10-142016-10-142016-10-14Bibliographically approved