Shedding light on dark matter with recent muon (g − 2) and Higgs exotic decay measurements

Recently, we have witnessed two hints of physics beyond the standard model: a 3.3 σ local excess ( M_A_0 = 52 GeV) in the search for H 0 → A 0 A 0 → b b μ + μ − and a 4.2 σ deviation from the SM prediction in the ( g − 2) μ measurement. The first excess was found by the ATLAS collaboration using 139 fb − 1 data at √(s) = 13 TeV. The second deviation is a combination of the results from the Brookhaven E821 and the recently reported Fermilab E989 experiment. We attempt to explain these deviations in terms of a renormalizable simplified dark matter model. Inspired by the null signal result from dark matter (DM) direct detection, we interpret the possible new particle, A 0 , as a pseudoscalar mediator connecting DM and the standard model. On the other hand, a new vector-like muon lepton can explain these two excesses at the same time while contributing to the DM phenomenology.