Anomalous magnetic moment and Higgs coupling of the muon in a sequential U(1) gauge model with dark matter

Dark Contributions to h → μ + μ – in the Presence of a μ-Flavored Vector-Like Lepton

“…Although the 𝐻-portal model with a real singlet scalar DM has already been ruled out for 𝑀DM ∈ [100, 1000] GeV by the current direct detection (DD) bounds, [10][11][12] a recent study [13] has shown that it can be revived within an effective field theory (EFT) framework if one extends the SM quark sector with a particular dimension-6 effective operator corresponding to an NP scale 𝛬NP. In contrast to the earlier studies, [14][15][16][17] the present study explicitly uses this idea to describe a DD-allowed real singlet scalar DM model which, in the presence of a dark 𝜇-flavored vector-like lepton (VLL), can result in a remarkable negative contribution to the muon Yukawa coupling at one-loop order. VLLs are phenomenologically well motivated [18][19][20][21][22] for describing an anomaly free UV complete theory, [23] whereas the flavor-specific choice helps to explain the nonobservation of the lepton flavor violating processes, e.g., ℎ → ℓ𝑖ℓ𝑗, ℓ𝑗 → ℓ𝑖𝛾, and ℓ𝑗 → 3ℓ𝑖.…”