Muon g−2 in the 2HDM: Maximum results and detailed phenomenology

Abstract

We analyze the maximum contributions to the muon magnetic moment a μ and Yukawa and triple Higgs couplings in the flavor-aligned two-Higgs doublet model (2HDM). We focus on the most promising case of a light pseudoscalar Higgs A with large Yukawa couplings to leptons and quarks. Taking into account experimental constraints from LHC Higgs and flavor physics, we find maximum possible Yukawa couplings of a light A of around 50-100 (leptons) and Oð0.5Þ (quarks). An overall maximum of a μ of more than 45 × 10 −10 is possible in a very small parameter region around M A ¼ 20 GeV. For M A up to 100 GeV, the maximum possible value of a μ is compatible with the currently observed deviation if the A couplings to quarks and leptons are both large, making this scenario promising for LHC searches. We also analyze the subleading bosonic two-loop contributions to a μ , finding values up to 3 × 10 −10 .

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

“…Our results are consistent with those of Ref. [26], such as tan β > 35 (60) Higgs. Therefore, an appropriate sin(β − α) is required to make | y h τ | to be around 1.0.…”

“…Thus, in the region of m A < 20 GeV, the acceptance of above signal region for final state of two collinear τ + Z/W boson quickly decreases.The production processes of the extra Higgses in Eqs (30,31). considered by us are the same as Eqs (26)(27)(28)(29). of Ref [17]…”

Electron EDM and muon anomalous magnetic moment in two-Higgs-doublet models

“…On the other hand, the observed deviation of the muon anomalous moment [17] can be explained in type-X 2HDM [18][19][20][21][22][23][24][25]. Both for EDM and the muon g − 2, sizable contributions come from two-loop Barr-Zee (BZ) diagrams [26].…”

Searching for a light Higgs boson via the Yukawa process at lepton colliders

“…A light pseudoscalar in the Lepton-specific or Type-X 2HDM is of particular interest as it can explain the observed anomaly of muon anomalous magnetic moment, (g − 2) µ , measured by the BNL collaboration [11,12] when the ratio of Higgs vacuum expectation values, tan β, is sufficiently large [10,13,[15][16][17][18][19]. Such a light pseudoscalar, denoted by A, in Type-X 2HDM with large tan β often remains undetected at the large hadron collider (LHC) by virtue of its hadrophbic nature, which makes the production of A via the gluon fusion process ineffective.…”