Improved EFT Constraints from Top Quark Pair Production Using CMS Run-II Data

This talk presents advancements in indirect searches for Beyond Standard Model (BSM) physics in top-quark pair production at the Large Hadron Collider. Building on previous work by the CMS Collaboration (PhysRevD.100.072002), which analyzed partial Run 2 data to constrain Effective Field Theory (EFT) couplings in the dileptonic decay channel, this study extends the analysis to the full Run-II dataset (2016-2018). The analysis adopts a two-pronged approach: a maximum likelihood estimation (MLE) at detector level and an unfolded chi-square method at parton level. The MLE method is used to estimate parameters like the Wilson Coefficient C_tG, which governs the top-quark–gluon interaction via a dipole operator. By incorporating systematic uncertainties as nuisance parameters and leveraging likelihood profiles, the MLE offers significant advantages in parameter precision over traditional methods. This analysis covers both dileptonic and semileptonic decay channels, including cases with boosted top quarks. With over 3 million reconstructed top quarks, the MLE framework efficiently handles higher-dimensional EFT parameter spaces, improving sensitivity to BSM physics.