Explanation of the 17 MeV Atomki anomaly in a U(1)′-extended two Higgs doublet model

Motivated by an anomaly observed in the decay of an excited state of Beryllium (Be-8) by the Atomki collaboration, we study an extension of the standard model with a gauged U(1)' symmetry in presence of a two Higgs doublet model structure of the Higgs sector. We show that this scenario complies with a variety of experimental results and is able to explain the potential presence of a resonant spin-1 gauge boson, Z', with a mass of 17 MeV in the Atomki experimental data, for appropriate choices of U(1)' charges and Yukawa interactions.