  In this work we numerically re-examine the loop-induced WIMP-nucleon
scattering cross section for the simplified dark matter models and the
constraint set by the latest direct detection experiment. We consider a
fermion, scalar or vector dark matter component from five simplified models
with leptophobic spin-0 mediators coupled only to Standard Model quarks and
dark matter particles. The tree-level WIMP-nucleon cross sections in these
models are all momentum-suppressed. We calculate the non-suppressed
spin-independent WIMP-nucleon cross sections from loop diagrams and investigate
the constrained space of dark matter mass and mediator mass by Xenon1T. The
constraints from indirect detection and collider search are also discussed.
