LHCtopWG Seminar

Tuesday 13 Apr 2021, 15:00 → 16:30 Europe/Zurich

CERN

Maria Aldaya Martin (DESY), Reinhard Schwienhorst (Michigan State University (US)), Wolfgang Wagner (Bergische Universitaet Wuppertal (DE))

1 Theory seminar: [arXiv:2102.11281] Signatures of toponium formation in LHC run 2 data

We study reported deviations between observations and theoretical predictions associated with the production of a pair of di-leptonically decaying top quarks at the LHC, and we examine the possibility that they reflect a signal of toponium formation. We investigate the production by gluon fusion of a color-singlet spin-0 toponium ηt bound state of a top and anti-top quark, that then decays di-leptonically (gg→ηt→ℓ¯ℓbb¯νν¯). We find strong correlations favoring the production of di-lepton systems featuring a small angular separation in azimuth and a small invariant mass. Although toponium production only contributes to 0.8% of the total top-quark pair-production cross section at the 13 TeV LHC, there is a possibility that it can account for observed excesses in the narrow edges of phase space. We propose a method to discover toponium formation by `reconstructing' both its top and anti-top quark constituents in the di-lepton channel.

Speaker: Benjamin Fuks (Centre National de la Recherche Scientifique (FR))

toponium_fuks.pdf

15:30 Discussion