During this research, they found two unexpected events, one in October 1946 and one in May 1947, showing previously unknown particles.

Now, given some number of unknown incoming particles, it is possible to reconstruct their energies using the picture of particle showers born in the calorimeter.

Or maybe this isn't Higgs that was seen but some unknown particles.

It looks like we have an unknown particle moving at light speeds through the spectrum.

Or it could point to a subtler interplay of particles, known and unknown.

"It means the computer is only eighty-six percent certain that the unknown particles found in this particular concentration are of Dominion origin."

It means that once again, the Standard Model of particle physics has predicted a previously unknown particle, which has then been found.

A widely-accepted theory is that the original decay produces two quarks and also a third unknown particle, dubbed the quason.

Still other particles, yet unknown, might be brought to the rescue of the hypothesis.

It is quite possible then that many of these collisions were caused by WIMPs, and/or other unknown particles.