Search for new physics using top quark pairs produced in association with a boosted Z or Higgs boson in effective field theory

A data sample containing top quark pairs produced in association with a boosted Z or Higgs boson is used to search for signs of new physics within the framework of effective field theory (EFT). The data correspond to an integrated luminosity of $137 \, \mathrm{fb}^{-1}$ of proton-proton collisions produced at a center-of-mass energy of 13 TeV at the LHC and collected by the CMS experiment. Selected collision events contain a single lepton and hadronic jets, including two identified with the decay of bottom quarks, plus an additional large-radius jet with high transverse momentum ($\mathrm{p}_{\mathrm{T}}$) identified as a Z or Higgs boson candidate decaying to a bottom quark pair. Machine learning techniques are employed to discriminate $\mathrm{t}\bar{\mathrm{t}}\mathrm{Z}$ and $\mathrm{t}\bar{\mathrm{t}}\mathrm{H}$ events from background processes, dominated by $\mathrm{t}\bar{\mathrm{t}}+\mathrm{jets}$ production. The signal strengths of boosted $\mathrm{t}\bar{\mathrm{t}}\mathrm{Z}$ and $\mathrm{t}\bar{\mathrm{t}}\mathrm{H}$ processes are measured, and upper limits are placed on the $\mathrm{t}\bar{\mathrm{t}}\mathrm{Z}$ and $\mathrm{t}\bar{\mathrm{t}}\mathrm{H}$ differential cross sections as functions of the Z or Higgs boson $\mathrm{p}_{\mathrm{T}}$.