Revisiting lepton-specific 2HDM in light of muon g-2 anomaly

We examine the lepton-specific 2HDM as a solution of muon g - 2 anomaly under various theoretical and experimental constraints, especially the direct search limits from the LHC and the requirement of a strong first-order phase transition in the early universe. We find that the muon g - 2 anomaly can be explained in the region of 32 < tan beta< 80, 10 GeV < m(A) < 65 GeV, 260 GeV < m(H) < 620 GeV and 180 GeV < m(H +/-) < 620 GeV after imposing the joint constraints from the theory, the precision electroweak data, the 125 GeV Higgs data, the leptonic/semi-hadronic tau decays, the leptonic Z decays and Br(B-s -> mu(+)mu(-)). The direct searches from the h -> AA channels can impose stringent upper limits on Br(h -> AA) and the multi-lepton event searches can sizably reduce the allowed region of m(A) and tan beta (10 GeV < m(A) < 44 GeV and 32 < tan beta < 60). Finally, we find that the model can produce a strong first-order phase transition in the region of 14 GeV < m(A) < 25 GeV, 310 GeV < m(H) < 355 GeV and 250 GeV < m(H +/-) < 295 GeV, allowed by the explanation of the muon g - 2 anomaly. (C) 2018 The Authors. Published by Elsevier B.V.