The existence of doubly charged Higgs bosons ($H^{\pm \pm }$) is a distinctive feature of the Higgs triplet model (HTM), in which neutrinos obtain tree-level masses from the vacuum expectation value of a neutral scalar in a triplet representation of $SU(2{)}_L$. We point out that a large branching ratio for the decay of a singly charged Higgs boson to a doubly charged Higgs boson via $H^{\pm }\to H^{\pm \pm }{W}^{*}$ is possible in a sizeable parameter space of the HTM. From the production mechanism $q^{\prime }\overline{q}\to W^{*}\to H^{\pm \pm }{H}^{\mp }$ the above decay mode would give rise to pair production of $H^{\pm \pm }$, with a cross section which can be comparable to that of the standard pair-production mechanism $q\overline{q}\to Z^{*}({\gamma }^{*})\to H^{++}{H}^{--}$. We suggest that the presence of a sizeable branching ratio for $H^{\pm }\to H^{\pm \pm }{W}^{*}$ could significantly enhance the detection prospects of $H^{\pm \pm }$ in the four-lepton channel. Moreover, the decays $H^0\to H^{\pm }{W}^{*}$ and $A^0\to H^{\pm }{W}^{*}$ from production of the neutral triplet scalars $H^0$ and $A^0$ would also provide an additional source of $H^{\pm }$, which can subsequently decay to $H^{\pm \pm }$.

• Received 17 May 2011

DOI:https://doi.org/10.1103/PhysRevD.84.035010