Fran, This could be a breakthrough... especially wrt LENR. Thanks for posting it. The particle could be real but completely unrelated to a so-called "5th force". That part is a stretch.
If accurate - it would go part way to explain Holmlid's "muon" which very few physicists believe is really a muon. One problem for that interpretation is that the new particle’s suspected mass is ~17 (MeV) whereas the muon is 106 MeV. Even so, Holmlid was ill-equipped to measure relevant details, and this would be a partial fit.------- Roarty, Francis X wrote: https://www.nature.com/news/has-a-hungarian-physics-lab-found-a-fifth-force-of-nature-1.19957