On the Validity of the Effective Field Theory for Dark Matter Searches at the LHC Part III: Analysis for the $t$-channel

TL;DR

This paper evaluates the validity of the effective field theory approach for dark matter searches at the LHC, specifically for t-channel interactions, providing analytical and simulation-based insights into its applicability and implications for dark matter relic abundance.

Contribution

It extends previous analyses by focusing on t-channel mediators, offering analytical validity criteria and Monte Carlo validation for different collider energies.

Findings

Effective field theory validity depends on mediator mass and energy scales.

In valid EFT regions, dark matter relic abundance tends to be large.

Monte Carlo simulations support analytical validity assessments.

Abstract

We extend our recent analysis of the limitations of the effective field theory approach to studying dark matter at the LHC, by investigating the case in which Dirac dark matter couples to standard model quarks via $t$-channel exchange of a heavy scalar mediator. We provide analytical results for the validity of the effective field theory description, for both $\sqrt{s}$ = 8 TeV and 14 TeV. We make use of a MonteCarlo event generator to assess the validity of our analytical conclusions. We also point out the general trend that in the regions where the effective field theory is valid, the dark matter relic abundance is typically large.