Precision calculations for tt̄, tt̄V production at the LHC
by
https://fisica-unimi.zoom.us/j/91725083965?pwd=NzVJV2dzV2RWdThQMnp3SHVpUUMzdz09
With the 13 TeV LHC run, both ATLAS and CMS collaborations have significantly reduced the experimental uncertainties on pp → tt̄ production measurements at the cross section and differential level. Furthermore, they have measured the pp → tt̄V (V = Z, W ) cross sections and these processes are studied either independently or as irreducible backgrounds to tt̄H searches. These experimental studies have reported various tensions between theory and experiment (e.g. p_T (t) in tt̄ production, jet multiplicities in tt̄W production), which point to the necessity for a better theoretical understanding of these processes within the SM.
In this seminar we will focus on the calculational status of these processes.
We will start the discussion with the top-quark pair production at complete-NLO accuracy with NNLO+NNLL` corrections in QCD, pointing out the improvements imposed by the inclusion of the various perturbative orders and comparing these results with the latest experimental data. We will proceed to the top-quark pair production in association with a massive boson (Z,W,H) at NLO+NNLL accuracy, revealing the peculiarities of the tt̄W production. Finally we will focus on the tt̄W production discussing the necessity to move to the decay level for more realistic comparisons and ways to simulate the process up to the final multilepton signatures.