Cosmological observations indicate the existence of the dark
sector with a new interaction transmitted by a boson of mass in the
range of 1 MeV-1GeV. The anomalies in pair creation cross section
discovered at ATOMKI (Hungary) can be explain by various possible
scenarios involving a boson with mass of 16.7 MeV (X17).
A theoretical research program is proposed with two main
directions. Firstly, the generalized Einstein theory in discrete
internal dimensions will include all the interactions of Nature and
Higgs field together with a massive U(1) gauge vector as components of
gravity. This framework can provide a natural explanation of the
existence of X17. Secondly, a three-body alpha cored model for the
excitations of 8Be, 12C, 16O and 20Ne with energies higher than 17 MeV
is proposed. Based on this model, some properties of those nuclei can be
calculated with and without contributions of X17 to be compared against
the future experiments.