PT Journal
AU ATLAS Collaboration (Aad, Gea
   Cabrera Urban, S
   Castillo Gimenez, V
   Costa, MJ
   Fernandez Martinez, P
   Ferrer, A
   Fiorini, L
   Fuster, J
   Garcia, C
   Garcia Navarro, JE
   Gonzalez de la Hoz, S
   Hernandez Jimenez, Y
   Higon-Rodriguez, E
   Irles Quiles, A
   Kaci, M
   King, M
   Lacasta, C
   Lacuesta, VR
   Marti-Garcia, S
   Mitsou, VA
   Moles-Valls, R
   Oliver Garcia, E
   Pedraza Lopez, S
   Perez Garcia-Estañ, MT
   Romero Adam, E
   Ros, E
   Salt, J
   Sanchez Martinez, V
   Soldevila, U
   Sanchez, J
   Torro Pastor, E
   Valero, A
   Valladolid Gallego, E
   Valls Ferrer, JA
   Vos, M
TI Measurement of Spin Correlation in Top-Antitop Quark Events and Search for Top Squark Pair Production in pp Collisions at root s=8 TeV Using the ATLAS Detector
SO Physical Review Letters
JI Phys. Rev. Lett.
PY 2015
BP 142001
EP 19pp
VL 114
IS 14
DI 10.1103/PhysRevLett.114.142001
LA English
AB A measurement of spin correlation in t (t) over bar 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 (t) over bar 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 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.
ER