Simple Standard Model Extension by Heavy Charged Scalar.

We consider a Standard Model extension by a heavy charged scalar gauged only under the $U_{Y}(1)$ weak hypercharge gauge group. Such an extension, being gauge invariant with respect to the SM gauge group, is a simple special case of the well known Zee model. Since the interactions of the charged scalar with the Standard Model fermions turn out to be significantly suppressed compared to the Standard Model interactions, the charged scalar provides an example of a long-lived charged particle being interesting to search for at the LHC. We present the pair and single production cross sections of the charged boson at different colliders and the possible decay widths for various boson masses. It is shown that the current ATLAS and CMS searches at 13 TeV collision energy lead to the bounds on the scalar boson mass of about 400 GeV. The limits are expected to be much larger for higher collision energies and, assuming $15~ab^{-1}$ integrated luminosity, reach about 4 TeV at future 27 TeV LHC thus covering the most interesting mass region.