Neutrino Constraints and the ATOMKI X17 Anomaly

Abstract

Recent data from the ATOMKI group continues to confirm their claim of the existence of a new $\sim 17$ MeV particle. We review and numerically analyze the data and then put into context constraints from other experiments, notably neutrino scattering experiments such as the latest reactor anti-neutrino coherent elastic neutrino nucleus scattering data and unitarity constraints from solar neutrino observations. We show that minimal scenarios are disfavored and discuss the model requirements to evade these constraints.

Comments: 11 pages, 4 figures, comments welcome! v2: analysis expanded, results similar, matches published version