Constraining the four-light quark operators in the SMEFT with multijet and VBF processes at linear level

TL;DR

This paper explores how multijet and vector boson fusion processes at linear level can constrain four-light quark operators in the SMEFT by analyzing differential distributions and their sensitivity to Wilson coefficients.

Contribution

It introduces a method to constrain SMEFT operators using merged and showered LO differential distributions from multijet and VBF processes, assessing the impact of quadratic terms.

Findings

Certain observables provide stronger bounds on Wilson coefficients.

Quadratic contributions are significant for EFT validity assessment.

Differential distributions help identify directions in coefficient space that are most constrained.

Abstract

We investigate how the interference of the SM with ten four-light quark operators in the SMEFT can be constrained thanks to multijet and $Z$, $W$, $\gamma$ VBF production in association with jets. The differential distributions for each process are generated at LO for different jet multiplicities, that are then merged and showered. We check which observables provide better bounds on the Wilson coefficients, and what directions in the ten-dimensional coefficient space they are able to probe. We discuss the relevance of the quadratic contributions with respect to the linear terms and use them to assess the validity of the EFT approach.