Resonance
Resonances are extremely short lived states of particles. A particle resonates
or "rings like a bell" when hit with a jolt of energy. It stores this
energy in the form of a mass increase. Resonances decay or give off this excess
energy in about 10 to the minus 23 seconds. A particle can only absorb certain
levels of mass as, like a bell, it can only "ring" at certain
frequencies. The resonances of some particles have been given different names
and some so-called particles may actually be resonances. A resonance occurs when
the net energy of the colliding subatomic particles is just enough to produce
its rest mass, which the strong force then causes to disintegrate within 10-23
second.