Always on the lookout for strange physics, I was fascinated by a Paper by Boer and Fields at ArXiv. They analysised 7 previous experiment all which should something bizarre, A new Light Neutral Boson. There particle has a mass range of 1.5MeV to 20MeV, a lifespan of about 10^-15 to 10^-16 seconds. And strangely shows up only in experiment using photograph Emulsion. There X boson appears to be made in the decay on the neutral pion, one decay out of every thousand, and itself decays into an electron positron pair. They don't even have bad statistics ranging for 2.8 sigma to 8 sigma in the different experiments the review.
A boson is a force carrying particle, given a mass of 1 MeV, Boer's and Field's particle would mediate a short range force novel to the standard model. Looking at previous limits to a fifth force, this particle is in a range previously thought to be ruled out. This might even be the axi-photon as predicted in my axial-force theory, which escapes the those fifth force limits. The axi-photon should gain mass, and additional decay modes (usually it would decay to a neutrino and anti-neutrino) in any dense medium with heavy nuclei, such as photographic emission. However i'd only expect a mass of about 5KeV and only very rare electron pair production. Boer's and Field's particle actual pair produces some thousand times quicker than an ordinary photon. Its very notifable that there particle is only observed in old fashioned photographic emulsion, most modern experiement don't use these, and don't observe the behaviour of particles at depth in ordinary matter. Perphaps thats why this new particle has
escaped our eyes, up to now.