When two heavy ions collide at very high relativistic energies, they penetrate one another, during which they become excited and are slowed down. This “stopping” process can be generated experimentally, as demonstrated on the Large Hadron Collider (LHC) at Europe’s CERN research center in Geneva (Switzerland).
Click here for original story, Physicists make new predictions about the collision of heavy ions at very high relativistic energies
Source: Phys.org