# Simplified dark matter models with loop effects in direct detection and the constraints from indirect detection and collider search

## TL;DR

This paper investigates simplified fermionic dark matter models with spin-0 mediators, highlighting the importance of loop effects in direct detection and analyzing constraints from indirect detection and collider experiments.

## Contribution

It provides detailed loop calculations for DM-nucleon interactions and assesses the sensitivity of future experiments to these models.

## Key findings

- Loop-induced contributions significantly enhance direct detection signals.
- Future experiments can probe part of the parameter space.
- Indirect detection and collider searches offer complementary constraints.

## Abstract

We reexamine the simplified dark matter (DM) models with fermionic DM particle and spin-0 mediator. The DM-nucleon scattering cross sections of these models are low-momentum suppressed at tree-level, but receive sizable loop-induced spin-independent contribution. We perform one-loop calculation for scalar-type and twist-2 DM-quark operators and complete two-loop calculation for scalar-type DM-gluon operator. By analyzing the loop-level contribution from new operators, we find that future direct detection experiments can be sensitive to a fraction of parameter space. The indirect detection and collider search also provide complementary constraints on these models.