  Many extensions of the standard model (SM) involve new massive particles
charged under the electroweak gauge symmetry. The electroweakly interacting new
particles affect various SM processes through radiative corrections. We discuss
the possibility of detecting such new particles based on the precise
measurement of the SM processes at high energy hadron colliders. It then turns
out that Drell-Yan processes receive radiative corrections from the
electroweakly interacting particles at the level of ${\cal O}$(0.1-10) %. It is
hence possible to indirectly search for the Higgsino up to the mass of 400 GeV
and the quintet (5-plet) Majorana fermion up to the mass of 1200 GeV at the
high-luminosity running of the Large Hadron Collider, if the systematic
uncertainty associated with the estimation of the SM background becomes lower
than the statistical one.
