A new anomaly observed in ${}^4$He supports the existence of the hypothetical X17 particle

A. J. Krasznahorkay, M. Csatlós, L. Csige +7

Energy-sum and angular correlation spectra of $e^{+}{e}^{-}$ pairs produced in the ${}^3$H(p,$\gamma$)${}^4$He nuclear reaction have been studied at $E_p$=510, 610 and 900 keV proton energies…