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
Publisher DOI
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 azimuthal angle between the two charged leptons in the laboratory frame. In the helicity basis the measured degree of correlation corresponds to A helicity =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.
Date Issued
2015
Publication Type
Article
Subject(s)
Language(s)
en
Author(s)
ATLAS, Collaboration | |
Kabana, Sonja |
Additional Credits
Journal
Physical review letters
Publisher
American Physical Society
ISSN
0031-9007
Access(Rights)
open.access