Search for a charged Higgs boson in pp collisions at √s = 8 TeV

A search for a charged Higgs boson is performed with a data sample corresponding to an integrated luminosity of 19.7 ± 0.5 fb^-1 collected with the CMS detector in proton-proton collisions at √s = 8,TeV. The charged Higgs boson is searched for in top quark decays for m_H± < m_t - m_b, and in the direct production pp → t(b)H^± for m_H± > m_t - m_b. The H^± → τ^±ν_τ and H^± → tb decay modes in the final states τ_h + jets, μτ_h, l+jets, and ll' (l = e, μ) are considered in the search. No signal is observed and 95% confidence level upper limits are set on the charged Higgs boson production. A model-independent upper limit on the product branching fraction B(t → H^±b) B(H^± → τ^±ν_τ ) = 1.2-0.15% is obtained in the mass range m_H± = 80-160 GeV, while the upper limit on the cross section times branching fraction σ(pp → t(b)H^±) B(H^± → τ^±ν_τ) = 0.38-0.025 pb is set in the mass range m_H+ = 180-600 GeV. Here, σ(pp → t(b)H^±) stands for the cross section sum (pp → t‾(b)H⁺) + σ(pp → t(b‾)H^-). Assuming B(H^± → tb) = 1, an upper limit on σ(pp → t(b)H^±) of 2.0-0.13 pb is set for m_H± = 180-600 GeV. The combination of all considered decay modes and final states is used to set exclusion limits in the m_H± -tanβ parameter space in different MSSM benchmark scenarios.