Natural Science Forum / Physics / Particle Physics / December 2004

As far as I know, all experimental evidence on the energy/mass ratio
confirms the value c^2 to an accuracy well within measurement errors.

Experiments that would point to a different value with any degree of
reliability would make big world news. Something analogous acutally
exists, namely beta decay processes of many species of atomic nuclei.

The still intact nucleus seems to contain energy that apparently gets
lost upon emission of a electron, i.e. the kinetic energies acquired by
the decay products do not account for the loss of mass during the
process. (loss of mass time c^2, of course). This phenomenon raised
serious doubt about the universal validity of the law of conservation of
energy. It led Wolfgang Pauli to the hypothesis of an unknown kind of
elementary particle, later named "neutrino", which turned out to be correct.

Therefore, if and when one would discover and confirm beyond any doubt
an energy leakage it would be time to hunt for a hitherto unknown kind
of elementary particle, and to revise or perhaps even to abolish the
Standard Model.
For the time being this is an academic remark only.

Johan E. Mebius