Charged Higgs phenomenology in the lepton-specific two Higgs doublet model

We study the ``lepton-specific'' two Higgs doublet model, in which one doublet Φ_ gives mass to charged leptons and the other Φq gives mass to both up- and down-type quarks. We examine the existing experimental constraints on the charged Higgs boson mass and the parameter tanβ≡⟨Φq⁰⟩/⟨Φ_⁰⟩. The most stringent constraints come from LEP-II direct searches and lepton flavor universality in τ decays. The former yields M_H^±≥92.0 GeV; the latter yields two allowed regions 0.61tanβ GeV≤M_H^±≤0.73tanβ GeV or M_H^±≥1.4tanβ GeV, and excludes parameter regions beyond the LEP-II bound for tanβ65. We present the charged Higgs decay branching fractions and discuss prospects for charged Higgs discovery at the LHC in this model.