Top quark production cross-section at LHC in ATLAS
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DrCarolina Gabaldon Ruiz(CNRS/LPSC)
→
Europe/Paris
bat 25, salle Mondrian
bat 25, salle Mondrian
Description
The Large Hadron Collider at CERN produces top quarks with a cross section
that is more than ten times that of the Tevatron. This provides an unprecedent ability
to study this quark, which is the most massive of the known elementary particles.
Top quarks are produced via two independent mechanisms in the Standard Model (SM).
The dominant mode is pair production (top-antitop) via the flavour-conserving strong interaction
of $gg$ ($85 \%$ at LHC) and $q \bar{q}$ fusion. The second mode is single top quarks via
the electroweak interaction.
The seminar summarises measurements made with the ATLAS detector of top pair and single top
production cross-sections using $pp$ collision data at centre-of-mass energies of 7 TeV
and 8 TeV. In particular, for the single top-quark production the results are interpreted in
terms of the CKM matrix element $|V_{tb}|$. Any observed deviation from the SM predictions
would give hints of exotic physics. The latest ATLAS measurements of the differential
top quark pair production cross-sections in the lepton plus jets channel will be also discussed,
providing an important test of perturbative QCD.
By Dr Carolina Gabaldon Ruiz.