INVESTIGADORES
MONTICELLI Fernando Gabriel
artículos
Título:
Search for New Phenomena in ttbar Events With Large Missing Transverse Momentum in Proton-Proton Collisions at √s = 7 TeV with 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. 231 p. 1 - 23
ISSN:
0031-9007
Resumen:
A search for new phenomena in ttbar events with large missing transverse
momentum in proton-proton collisions at a center-of-mass energy of 7
TeV is presented. The measurement is based on 1.04 fb^-1 of data
collected with the ATLAS detector at the LHC. The search is carried out
in the single-lepton channel, characterized by an isolated lepton of
high transverse momentum, four or more jets and large missing transverse
momentum. Contributions to this final state may arise from a number of
Standard Model extensions. The results are interpreted in terms of a
model where new top-quark partners are pair-produced and each decay to
an on-shell top (or antitop) quark and a long-lived undetected neutral
particle. The data are found to be consistent with Standard Model
expectations. A limit at 95% confidence level is set excluding a
cross-section times branching ratio of 1.1 pb for a top-partner mass of
420 GeV and a neutral particle mass less than 10 GeV. In a model of
exotic fourth generation quarks, top-partner masses are excluded up to
420 GeV and neutral particle masses up to 140 GeV.