Charged Higgs boson effects in the production and decay of a heavy Majorana neutrino at the CERN LHC

Abstract

We consider a new interaction between a heavy Majorana neutrino ($N$) and a charged Higgs boson (${H}^{\ifmmode\pm\else\textpm\fi{}}$), and show that it can have drastic implications on lepton-number-violating (LNV) signal of same-sign dileptons at the CERN LHC. The LNV signal of heavy Majorana neutrinos previously considered at the LHC, $pp\ensuremath{\rightarrow}{\ensuremath{\ell}}^{+}N\ensuremath{\rightarrow}{\ensuremath{\ell}}^{+}{\ensuremath{\ell}}^{+}{W}^{\ensuremath{-}}$, may be overwhelmed by $pp\ensuremath{\rightarrow}{\ensuremath{\ell}}^{+}N\ensuremath{\rightarrow}{\ensuremath{\ell}}^{+}{\ensuremath{\ell}}^{+}{H}^{\ensuremath{-}}$. With the subsequent decays ${H}^{\ensuremath{-}}\ensuremath{\rightarrow}\overline{t}b$ or ${H}^{\ensuremath{-}}\ensuremath{\rightarrow}{W}^{\ensuremath{-}}{H}^{0}$, the heavy Majorana neutrino production leads to the spectacular events of ${\ensuremath{\ell}}^{+}{\ensuremath{\ell}}^{+}b\overline{b}+2$ jets. We also explore the case ${m}_{N}<{m}_{{H}^{+}}$, where the decay ${H}^{+}\ensuremath{\rightarrow}{\ensuremath{\ell}}^{+}N$ can become the dominant $N$-production mechanism at the LHC. In particular, we show that the process $gb\ensuremath{\rightarrow}t{H}^{\ensuremath{-}}$ followed by $t\ensuremath{\rightarrow}b{W}^{+}$ and ${H}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\ell}}^{\ensuremath{-}}N\ensuremath{\rightarrow}{\ensuremath{\ell}}^{\ensuremath{-}}{\ensuremath{\ell}}^{\ensuremath{-}}{W}^{+}$ could lead to another type of spectacular events of ${\ensuremath{\ell}}^{\ensuremath{-}}{\ensuremath{\ell}}^{\ensuremath{-}}b+4$ jets.