<Dd> N + α → O + p </Dd> <P> This was the first - discovered nuclear reaction . </P> <P> To the pictures on the right: According to the energy - loss curve by Bragg it is recognizable that the alpha particle indeed loses more energy on the end of the trace . </P> <P> In 2011, members of the international STAR collaboration using the Relativistic Heavy Ion Collider at the U.S. Department of Energy's Brookhaven National Laboratory detected the antimatter partner of the helium nucleus, also known as the anti-alpha . The experiment used gold ions moving at nearly the speed of light and colliding head on to produce the antiparticle . </P>

Charge and mass of proton and alpha particle