Simultaneous SMEFT and PDF fits#

Here we provide the results of a simultaneous PDF and SMEFT determination in the top sector.

The simultaneous PDF and SMEFT fit shown here can be reproduced using the SIMUnet methodology: see the tutorials section for more details.

Below, we show the PDF resulting from the simultaneous fit in green. This SMEFT PDF is compared two SM PDF fits: NNPDF4.0-notop (no top data) and fit H (all top data), both of which are discussed in more detail in the SM PDFs section.

We observe that the impact of the top quark data on the large-x gluon PDF is diluted in the simultaneous fit: the Wilson coefficients reabsorb some of the constraining power of the top sector.

../_images/sm_smeft_pdf.png — Comparison between a SMEFT PDF and SM PDFs (left) and their uncertainties (right).#

The constraints on the Wilson coefficients of the SMEFT are shown below. We compare the constraints from the simultaneous fit with the constraints from a fixed-PDF fit, and find that the constrainst are stable.

../_images/smeft-pdf-95cl-bounds.png — Constraints on 20 Wilson coefficients of the dimension-6 SMEFT at \(\mathcal{O}(\Lambda^{-2})\).#