Professor Daniela Bortoletto

Abstract:

Searches for anomalous top quark-antiquark production are presented, based on pp collisions at √s=8 TeV. The data, corresponding to an integrated luminosity of 19.7 fb-1, were collected with the CMS detector at the LHC. The observed tt̄ invariant mass spectrum is found to be compatible with the standard model prediction. Limits on the production cross section times branching fraction probe, for the first time, a region of parameter space for certain models of new physics not yet constrained by precision measurements. © 2013 CERN.

Abstract:

The integrated and differential fiducial cross sections for the production of a W or Z boson in association with a high-energy photon are measured using pp collisions at √s = 7 TeV. The analyses use a data sample with an integrated luminosity of 4.6 fb-1 collected by the ATLAS detector during the 2011 LHC data-taking period. Events are selected using leptonic decays of the W and Z bosons (W(ev,μv) and Z(e+e-, μ+μ-, vv-)) with the requirement of an associated isolated photon. The data are used to test the electroweak sector of the Standard Model and search for evidence for new phenomena. The measurements are used to probe the anomalous WWγ, ZZγ and Zγγ triple-gauge-boson couplings and to search for the production of vector resonances decaying to Zγ and Wγ. No deviations from Standard Model predictions are observed and limits are placed on anomalous triple-gauge-boson couplings and on the production of new vector meson resonances. © Copyright owned by the author(s).