The Toponium bound state — A few considerations about its production at the LHC

• Antonio Davide Polosa (Istituto Nazionale di Fisica Nucleare)

Room: Aula Conversi

Spot on the tt̄ threshold: quasi-bound states or BSM Physics?

• Alexander Grohsjean (Deutsches Elektronen Synchrotron)

Room: Aula Conversi Recent measurements by CMS and ATLAS at the LHC have independently revealed an intriguing excess near the top quark–antiquark production threshold. In this seminar, I will present the CMS analysis in the dileptonic channel based on the full Run II dataset. The observed excess is compatible with contributions from a short-lived ¹S₀ quasi-bound state (“toponium”), but can also be interpreted in terms of heavy scalar or pseudoscalar resonances. A comparison with the ATLAS result and prospects for clarifying the origin of this enhancement in future measurements will be discussed. Zoom link: https://uniroma1.zoom.us/j/87038625161?pwd=cEtGRjZNT2VWSlJIWmxaYmxSMDhRZz0