The decades-long hunt for an antiproton

On October 19, 1955, the discovery of the antiproton was announced. The culmination of a decades-long hunt for the particle, the discovery won its discoverers Emilio Segre and Owen Chamberlain the 1959 Nobel Prize for Physics. A.S.Ganesh tells you how the first group discovered the antiprotons from a pool of millions of particles...

Subatomic particles of the same mass as a proton but having a negative electric charge and oppositely directed magnetic moment, antiprotons are the antiparticles of protons. Even though they are stable, they are typically short-lived as collision with any proton causes both particles to annihilate in a burst of energy.

Even though antiprotons were discovered only in 1955, we will have to go back a few decades further to get our foundations right. For it was in 1928 that Paul Dirac, a brilliant and eccentric English theoretical physicist, formulated an equation to describe the behaviour of relativistic electrons in electric and magnetic fields.