  The CMS Collaboration at the LHC recently reported an accumulation of data
around 28 GeV in the invariant-mass distribution of muon pairs in association
with a b quark jet and at least a second jet. This is analysed here in the
light of the possible existence of a (pseudo)scalar boson with mass of about
57.5 GeV. We find that part of the data may originate in the radiative decay of
Z bosons into pairs consisting of the lighter boson and a photon, giving rise
to dimuon decay products that either stem from the photon or from the
(pseudo)scalar boson.
