Single and pair production of doubly charged Higgs bosons at hadron colliders

Current searches for doubly charged Higgs bosons (H-+/-+/-) at the Fermilab Tevatron are sensitive to single production of H-+/-+/-, although the pair production mechanism q (q) over bar -> H++H-- is assumed to be dominant. In the context of a Higgs Triplet Model we study the mechanism q (q) over bar ->(HH -/+)-H-+/-+/- at the Tevatron and CERN Large Hadron Collider, and show that its inclusion can significantly improve the search potential for H-+/-+/-. Moreover, assuming that the neutrino mass is generated solely by the triplet field Yukawa coupling to leptons, we compare the branching ratios of H-+/-+/--> l(+/-)l(+/-) and H-+/-+/-->(HW*)-W-+/- for the cases of a normal hierarchical, inverted hierarchical, and degenerate neutrino mass spectrum.