SMEFT-only fit#

We provide bounds on 25 Wilson coefficients of the dimension-6 SMEFT relevant for LHC top quark observables.

The relative constraining power (%) of each sector of top quark observables on the SMEFT coefficients is shown below: see [Kassabov et al., 2023] for more details.

../_images/plot_fisher_information_by_sector.png

First, we show the results of a determination of these Wilson coefficients at linear order (\(\Lambda^{-2}\)). Here we assume a fixed SM PDF as input to our theoretical calculations. This type of ‘fixed-PDF’ fit can be reproduced using the SIMUnet methodology: see the tutorials section for more details.

../_images/smeft_lin_nlo_comparison.png — Constraints on 20 Wilson coefficients of the dimension-6 SMEFT at \(\mathcal{O}(\Lambda^{-2})\).#

The results of the same fit, this time determined at quadratic order in the EFT expansion (\(\Lambda^{-2}\)), are shown below. As above, a fixed PDF set is used.

../_images/smeft_quad_nlo_comparison.png — Constraints on 25 Wilson coefficients of the dimension-6 SMEFT at \(\mathcal{O}(\Lambda^{-4})\).#

Below, we highlight the correlations between the Wilson coefficients resulting from the fit: on the left, we show the correlations arising at linear order, while the correlations in a quadratic fit are shown on the right.