Abstract
A measurement of spin correlation in $t\bar{t}$ 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 $t\bar{t}$ 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 $A_{helicity} = 0.38 \pm 0.04$, 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.
Original language | English |
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Article number | Aad:2014mfk |
Pages (from-to) | 142001 |
Journal | Physical Review Letters |
Volume | 114 |
Issue number | 14 |
DOIs | |
Publication status | Published - 8 Apr 2015 |
Keywords
- hep-ex
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Liza Mijovic
- School of Physics and Astronomy - Senior Research Associate
Person: Academic: Research Active (Research Assistant)