Measurement of Spin Correlation in Top-Antitop Quark Events and Search for Top Squark Pair Production in pp Collisions at √s =8  TeV Using the ATLAS Detector

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@article{ce54bca757cd4297a8273a85886a2f94,
title = "Measurement of Spin Correlation in Top-Antitop Quark Events and Search for Top Squark Pair Production in pp Collisions at √s =8  TeV Using the ATLAS Detector",
abstract = "A measurement of spin correlation in tt¯ production is presented using data collected with the ATLAS detector at the Large Hadron Collider in proton-proton collisions at a center-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 20.3  fb-1. The correlation between the top and antitop quark spins is extracted from dilepton tt¯ events by using the difference in the azimuthal angle between the two charged leptons in the laboratory frame. In the helicity basis the measured degree of correlation corresponds to Ahelicity=0.38±0.04, in agreement with the standard model prediction. A search is performed for pair production of top squarks with masses close to the top quark mass decaying to predominantly right-handed top quarks and a light neutralino, the lightest supersymmetric particle. Top squarks with masses between the top quark mass and 191 GeV are excluded at the 95% confidence level.",
keywords = "hep-ex",
author = "Laura Gonella and Benedict Allbrooke and {Aperio Bella}, Ludovica and Hardeep Bansil and Juraj Bracinik and David Charlton and Andrew Chisholm and Andrew Daniells and Simon Head and Christopher Hawkes and Stephen Hillier and Mark Levy and Richard Mudd and {Murillo Quijada}, Javier and Paul Newman and Konstantinos Nikolopoulos and Jody Palmer and Mark Slater and Jurgen Thomas and Paul Thompson and Alan Watson and Miriam Watson and John Wilson and {ATLAS Collaboration}",
note = "7 pages plus author list + cover pages (20 pages total), 2 figures, 2 tables, submitted to PRL, All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/TOPQ-2014-07/",
year = "2015",
month = apr,
doi = "10.1103/PhysRevLett.114.142001",
language = "English",
volume = "114",
journal = "Physical Review Letters",
issn = "0031-9007",
publisher = "American Physical Society (APS)",

}

RIS

TY - JOUR

T1 - Measurement of Spin Correlation in Top-Antitop Quark Events and Search for Top Squark Pair Production in pp Collisions at √s =8  TeV Using the ATLAS Detector

AU - Gonella, Laura

AU - Allbrooke, Benedict

AU - Aperio Bella, Ludovica

AU - Bansil, Hardeep

AU - Bracinik, Juraj

AU - Charlton, David

AU - Chisholm, Andrew

AU - Daniells, Andrew

AU - Head, Simon

AU - Hawkes, Christopher

AU - Hillier, Stephen

AU - Levy, Mark

AU - Mudd, Richard

AU - Murillo Quijada, Javier

AU - Newman, Paul

AU - Nikolopoulos, Konstantinos

AU - Palmer, Jody

AU - Slater, Mark

AU - Thomas, Jurgen

AU - Thompson, Paul

AU - Watson, Alan

AU - Watson, Miriam

AU - Wilson, John

AU - ATLAS Collaboration

N1 - 7 pages plus author list + cover pages (20 pages total), 2 figures, 2 tables, submitted to PRL, All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/TOPQ-2014-07/

PY - 2015/4

Y1 - 2015/4

N2 - A measurement of spin correlation in tt¯ production is presented using data collected with the ATLAS detector at the Large Hadron Collider in proton-proton collisions at a center-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 20.3  fb-1. The correlation between the top and antitop quark spins is extracted from dilepton tt¯ events by using the difference in the azimuthal angle between the two charged leptons in the laboratory frame. In the helicity basis the measured degree of correlation corresponds to Ahelicity=0.38±0.04, in agreement with the standard model prediction. A search is performed for pair production of top squarks with masses close to the top quark mass decaying to predominantly right-handed top quarks and a light neutralino, the lightest supersymmetric particle. Top squarks with masses between the top quark mass and 191 GeV are excluded at the 95% confidence level.

AB - A measurement of spin correlation in tt¯ production is presented using data collected with the ATLAS detector at the Large Hadron Collider in proton-proton collisions at a center-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 20.3  fb-1. The correlation between the top and antitop quark spins is extracted from dilepton tt¯ events by using the difference in the azimuthal angle between the two charged leptons in the laboratory frame. In the helicity basis the measured degree of correlation corresponds to Ahelicity=0.38±0.04, in agreement with the standard model prediction. A search is performed for pair production of top squarks with masses close to the top quark mass decaying to predominantly right-handed top quarks and a light neutralino, the lightest supersymmetric particle. Top squarks with masses between the top quark mass and 191 GeV are excluded at the 95% confidence level.

KW - hep-ex

U2 - 10.1103/PhysRevLett.114.142001

DO - 10.1103/PhysRevLett.114.142001

M3 - Article

VL - 114

JO - Physical Review Letters

JF - Physical Review Letters

SN - 0031-9007

M1 - 142001

ER -