  Direct searches of dark matter are performed at accelerator facilities. The
existence of a new vector boson has been postulated in different scenarios
where in the most basic scheme the coupling to the SM can be achieved via a
kinetic mixing term due to the U boson. The KLOE experiment at DA$\phi$NE
searched for the U boson both in Dalitz decays of the $\phi$ meson and in
continuum events. For all of these searches an upper limit for the U boson
coupling $\epsilon^{2}$ has been established in the mass range $50 \,
\text{MeV} < m_U < 1000\,\text{MeV}$. A summary of the different models and
searches along with results are presented.
