Charged Higgs scalar production in the single-top-quark mode (and others) at futureepcolliders in the minimal supersymmetric standard model

Abstract

We study charged Higgs boson production at future electron-proton colliders in the framework of the Minimal Supersymmetric Standard Model. We focus our attention to the case of single-top production and decay through the channel $t\to bH^\pm$ and of vector-scalar fusion via $W^{\pm*} \Phi^*\to H^\pm$ (where $\Phi=H,h$ and $A$). We consider the signature $H^\pm\to \tau\nu_\tau$ and compare it to the irreducible background from Standard Model interactions. For $M_{H^\pm}<m_t$, the $H^\pm$ signal is accessible through lepton universality breaking if $M_A<100-120$ GeV at both low and large values of $\tan\beta$. Furthermore, although the bulk of the production cross section comes from single-top events, a sizable contribution due to vector-scalar-scalar interactions should be observable at large $\tan\beta$, this possibly offering some insights into the structure of the scalar sector of the theory. The possibility of the CERN collider running in the LEPXLHC mode is considered in detail