INVESTIGADORES
MONTICELLI Fernando Gabriel
artículos
Título:
Observation of spin correlation in ttbar events from pp collisions at √s = 7 TeV using the ATLAS detector
Autor/es:
ATLAS COLLABORATION, G. AAD, F. MONTICELLI, ET AL
Revista:
PHYSICAL REVIEW LETTERS
Editorial:
AMER PHYSICAL SOC
Referencias:
Lugar: New York; Año: 2012 vol. 213 p. 1 - 23
ISSN:
0031-9007
Resumen:
A measurement of spin correlation in ttbar production is reported using
data collected with the ATLAS detector at the LHC, corresponding to an
integrated luminosity of 2.1 fb^-1. Candidate events are selected in the
dilepton topology with large missing transverse energy and at least two
jets. The difference in azimuthal angle between the two charged leptons
in the laboratory frame is used to extract the correlation between the
top and antitop quark spins. In the helicity basis the measured degree
of correlation corresponds to 0.40 +0.09 -0.08, in agreement with the
next-to-leading-order Standard Model prediction. The hypothesis of zero
spin correlation is excluded at 5.1 standard deviations.