Complete SMEFT predictions for four top quark production at hadron colliders

TL;DR

This paper provides comprehensive SMEFT predictions for four top quark production at hadron colliders, including all relevant operators and orders, to improve sensitivity to new physics through detailed differential and inclusive analyses.

Contribution

It offers the first complete tree-level SMEFT predictions for four top production, including subleading terms and double insertions, enhancing the accuracy of new physics constraints.

Findings

Subleading terms can significantly impact predictions.

Differential information improves sensitivity to SMEFT operators.

Higher order terms may enhance the detection prospects of new physics.

Abstract

We study four top quark production at hadron colliders in the Standard Model Effective Field Theory (SMEFT). We perform an analysis at the tree-level, including all possible QCD- and EW-coupling orders and relevant dimension-six operators. We find several cases where formally subleading terms give rise to significant contributions, potentially providing sensitivity to a broad class of operators. Inclusive and differential predictions are presented for the LHC and a future $pp$ circular collider operating at $100$ TeV. We estimate the sensitivity of different operators and perform a simplified chi-square fit to set limits on SMEFT Wilson coefficients. In so doing, we assess the importance of including subleading terms and differential information in constraining new physics contributions. Finally, we compute the SMEFT predictions for the double insertion of dimension-six operators and scrutinise the possible enhancements to the sensitivity induced by a specific class of higher order terms in the EFT series.