It is so dense that no known particles are able to escape the advancing core front except for neutrinos.

Here one stark difficulty is represented by the mysterious dark matter, which certainly cannot be accounted by the known particles.

This would make the exotic meson the only known particle containing more than three quarks.

As accelerators have grown, so too has the list of known particles that they might be used to investigate.

If it is true, all of the known elementary particles have partners, as yet undiscovered, but which might constitute the dark matter in the universe.

Upward because no other known particle can traverse the entire Earth.

Of all the known particles, they are the most mysterious and the hardest to observe.

All other known particles disintegrate in a few millionths of a second or less.

He wanted to tell her the truth, every known particle of it.

According to supersymmetry, however, every known particle has an undiscovered partner.