2,107 research outputs found
Modeling Radiation Damage to Pixel Sensors in the ATLAS Detector
Silicon pixel detectors are at the core of the current ATLAS detector and its
planned upgrade. As the detectors in closest proximity to the interaction
point, they will be exposed to a significant amount of radiation: prior to the
HL-LHC, the innermost layers will receive a fluence in excess of 1
MeV and the HL-LHC detector upgrades must cope
with an order of magnitude higher fluence integrated over their lifetimes. This
talk presents a digitization model that includes radiation damage effects to
the ATLAS Pixel sensors for the first time. After a thorough description of the
setup, predictions for basic pixel cluster properties are presented alongside
first validation studies with Run 2 collision data.Comment: 12 pages, 13 figures; Talk presented at the APS Division of Particles
and Fields Meeting (DPF 2017), July 31-August 4, 2017, Fermilab. C17073
Jet Charge with the ATLAS Detector using TeV Collision Data
The momentum-weighted sum of the charges of tracks associated to a jet
provides an experimental handle on the electric charge of fundamental
strongly-interacting particles. An overview of a study of this jet charge
observable for jets produced in dijet and semileptonic events using
of data with the ATLAS detector at TeV is
described here. In addition to providing a constraint on hadronization models,
jet charge has many possible applications in measurements and searches. The
modelling of jet charge and its performance as a charge-tagger are studied in
order to establish this observable as a tool for future physics analyses.Comment: Proceedings for a poster presented at LHCP 201
Limits on new coloured fermions using precision jet data from the Large Hadron Collider
This work presents an interpretation of high precision jet data from the
ATLAS experiment in terms of exclusion limits for new coloured matter. To this
end, the effect of a new coloured fermion with a mass on the solution of
the renormalization group equation QCD is studied. Theoretical predictions for
the transverse energy-energy correlation function and its asymmetry are
obtained with such a modified solution and, from the comparison to data, 95\%
CL exclusion limits are set on such models.Comment: 16 pages, 8 figures. v3 matches the published versio
Sneaky light stop
A light supersymmetric top quark partner (stop) with a mass nearly degenerate
with that of the Standard Model (SM) top quark can evade direct searches. The
precise measurement of SM top properties such as the cross-section has been
suggested to give a handle for this `stealth stop' scenario. We present an
estimate of the potential impact a light stop may have on top quark mass
measurements. The results indicate that certain light stop models may induce a
bias of up to a few GeV, and that this effect can hide the shift in, and hence
sensitivity from, cross-section measurements. The studies make some simplifying
assumptions for the top quark measurement technique, and are based on
truth-level samples
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