When this particle collides with its antiparticle, gamma ray photons may be produced. Davisson and Germer fired a beam of this particle at a nickel target to confirm the de Broglie hypothesis in their namesake experiment and 
When this particle collides with its antiparticle, gamma ray photons may be produced. Davisson and Germer fired a beam of this particle at a nickel target to confirm the de Broglie hypothesis in their namesake experiment and shifts in this particle's energy levels are described via the Auger Effect. With a mass of about 1/1836 that of a proton's, this particle was discovered using cathode rays by J.J. Thomson and its charge was measured by Robert Millikan's oil drop experiment. The analogue of the positron is, for 10 points, what fundamental particle with a negative charge.
When this particle collides with its antiparticle, gamma ray photons may be produced.
{electron}