Charting the Unseen: From Precision Top Measurements to Global SMEFT Fits at ATLAS

by Thomas James Stevenson (University of Sussex (GB))

Tuesday 17 Nov 2026, 11:00 → 12:00 Europe/Zurich

222/R-001 (CERN)

New physics may be hiding in plain sight, leaving subtle deviations from Standard Model predictions across a broad range of processes rather than a striking signal in any single measurement. The Standard Model Effective Field Theory (SMEFT) provides a powerful framework to search for such effects in a model-agnostic way. Since different processes can probe the same underlying interactions, combining measurements is essential to disentangle their contributions, resolve degeneracies, and maximise sensitivity to physics beyond the Standard Model.

This seminar presents different experimental approaches to this powerful framework.  A recent ATLAS measurement using the associated production of top-quark events with bosons or other top quarks compares two different strategies: one based on isolating specific Standard Model processes, and a signature-based strategy where final states with different reconstructed physics objects are isolated. Additionally, a global SMEFT analysis using large datasets of Standard Model processes involving Higgs-boson, vector-boson, and top-quark production events, as well as electroweak precision LEP data is also presented.

These results, based on the full Run 2 dataset, illustrate how complementary analysis strategies and the combination of diverse measurements can sharpen our sensitivity to new interactions and reveal correlations that would otherwise remain hidden. They also lay the groundwork for an increasingly comprehensive exploration of the SMEFT landscape with Run 3 data and beyond.

 

 

Coffee will be served at 10h30