Study of top quark pair production at the threshold using CMS data

by Alexander Grohsjean (Hamburg University)

Friday 3 Jul 2026, 14:30 → 16:00 Europe/Rome

1/1-2 - Aula "C. Voci" (Dipartimento di Fisica e Astronomia - Edificio Marzolo)

This seminar is organized by Group 1 of INFN Padova.

An excess of top quark pair events in the dilepton channel was first reported by CMS in 2024 and later confirmed by ATLAS. CMS now presents a new measurement in the single-lepton channel, obtaining a cross section of 5.1 ± 0.9 pb, consistent with the arlier dilepton result. The single-lepton channel is statistically independent of the dilepton channel and less sensitive to systematic uncertainties related to the jet energy scale calibration and the top quark mass. The observed excess is consistent with a simplified model of a color-singlet pseudoscalar toponium motivated by nonrelativistic quantum chromodynamics. The seminar will present the CMS measurements in both channels.