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

, The ATLAS collaboration (2015) 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. Physical review letters, 114 (14). ISSN 1079-7114

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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.

Item Type:
Journal Article
Journal or Publication Title:
Physical review letters
Additional Information:
© 2015 CERN, for the ATLAS Collaboration
Uncontrolled Keywords:
/dk/atira/pure/subjectarea/asjc/3100
Subjects:
ID Code:
74063
Deposited By:
Deposited On:
18 Jun 2015 06:00
Refereed?:
Yes
Published?:
Published
Last Modified:
29 Nov 2020 02:44