1. Doubly charged Higgs bosons at Hadron Colliders and neutrino mass hierarchy Mayumi Aoki (KEK) A.G.Akeroyd and M.A. PRD72,035011 (2005) (hep-ph/0506176)

2. Motivation （ Q=I 3 +Y/2 ） The observed neutrino oscillation data predict nonzero neutrino masses and mixings. Higgs Triplet Model : SM + Δ SU(2) L Higgs triplet boson (Y=2) LEP The most striking signature of Δ would be the observation of H ±±. H ±± →ℓ i ± ℓ j ± strong search potential Hadron colliders

3. Motivation CDF Collab. PRL93(2004) Assuming B(H ±± →l i ± l j ± )=100% 240pb -1 of data collected at √s=1.96TeV CDFII Tevatron Single production of H ±± Nonleptonic decay (for ｍ H±± > ｍ H± ) H ±± →l i ± l j ± in light of neutrino data We study the search potential for H ±± at Tevatron in HTM. only 1 B.Dion et al, PRD59 (1999) E.J.Chun et al, PLB566(2003) S.Chakrabarti et al, PLB434 (1998) J.F.Gunion et al, hep-ph/9610237

4. Higgs Triplet Model Δ ０ develops a VEV : Neutrino mass matrix We are interested in 03.0 10|1| 3        Physical Higgs bosons

5. Production of H ±± at Tevatron Total H ±± cross section Single H ±± production can be as large as the pair production. Mass limit on m H ±± increases significantly.

6. Decay of H ±± The total leptonic decay width depends on which solution to the neutrino mass hierarchy is realized. Leptonic decay Normal hierarchy (NH) Inverted hierarchy (IH) Degenerate (DG)

7. Decay of H ±± G: phase space factor Nonleptonic decay H ±± → H ± W ( * ) Current search strategy is ineffective. Current search strategy is effective. If H ±± → ℓ ± ℓ ± are measured then the ratios of h ij can be evaluated. An order of magnitude estimate of h ij could be obtaiened.

8. Limit on m H ±± Bilepton cross section m H ±± > 130 GeV (μμ)

9. Majorana phase dependence Assuming CP conservation, the following different patterns can be allowed. m H ±± > 138 GeV (ee)m H ±± > 120 GeV (eμ)

10. m H ±± > 132 GeV (μμ)m H ±± > 122 GeV (ee) m H ±± > 105 GeV (eμ) m H ±± > 115 GeV (μμ)

11. Summary We have studied the search potential for H ±± at Tevatron. Higgs Triplet Model : SM + Δ SU(2) L Higgs triplet boson (Y=2) production decay We encourage a detailed experimental simulation of this decay mode at Tevatron. significantly improves the search potential for H ±± might be helpful to determine the absolute value of h ij. Neutrino mass spectrum might be distinguished by the leptonic decay mode.

12. LHC Total H ±± cross section sensitivity up to 1 TeV