INVESTIGADORES
WAHLBERG Hernan Pablo
artículos
Título:
Search for top squark pair production in final states with one isolated lepton, jets, and missing transverse momentum in $\sqrt s =$8 TeV $pp$ collisions with the ATLAS detector
Autor/es:
H. WAHLBERG Y ATLAS COLLABORATION
Revista:
JOURNAL OF HIGH ENERGY PHYSICS
Editorial:
SPRINGER
Referencias:
Lugar: Berlin; Año: 2014
ISSN:
1126-6708
Resumen:
The results of a search for top squark (stop) pair production in final
states with one isolated lepton, jets, and missing transverse momentum
are reported. The analysis is performed with proton-proton collision
data at s√ = 8 TeV collected with the ATLAS detector at the LHC in 2012 corresponding to an integrated luminosity of 20 fb−1.
The lightest supersymmetric particle (LSP) is taken to be the lightest
neutralino which only interacts weakly and is assumed to be stable. The
stop decay modes considered are those to a top quark and the LSP as well
as to a bottom quark and the lightest chargino, where the chargino
decays to the LSP by emitting a W boson. A
wide range of scenarios with different mass splittings between the stop,
the lightest neutralino and the lightest chargino are considered,
including cases where the W bosons or the
top quarks are off-shell. Decay modes involving the heavier charginos
and neutralinos are addressed using a set of phenomenological models of
supersymmetry. No significant excess over the Standard Model prediction
is observed. A stop with a mass between 210 and 640 GeV decaying
directly to a top quark and a massless LSP is excluded at 95% confidence
level, and in models where the mass of the lightest chargino is twice
that of the LSP, stops are excluded at 95% confidence level up to a mass
of 500 GeV for an LSP mass in the range of 100 to 150 GeV. Stringent
exclusion limits are also derived for all other stop decay modes
considered, and model-independent upper limits are set on the visible
cross-section for processes beyond the Standard Model.