The following is a paper by H. Aspden published in Lettere al Nuovo Cimento, v. 26, pp. 257-260 (1979).
This paper shows how the author's derivation of the proton-electron mass ratio, the subject of paper 1975a leads directly to the psi particle of 3,684 MeV and its decay products. It is best read in its full non-abstracted form as a PDF file 1979c