Hautes Energies

Top quark production cross-section at LHC in ATLAS

par Dr Carolina 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.
Slides