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

Abstract Recently, we have witnessed two hints of physics beyond the standard model: a 3.3σ local excess ( M A 0 $$ {M}_{A_0} $$ = 52 GeV) in the search for H 0 → A 0 A 0 → b b ¯ $$ \overline{b} $$ μ + μ − and a 4.2σ 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 $$ \sqrt{s} $$ = 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