Question

A very small sub-atomic particle was passed through large tanks on water containing Cadmium when two gamma-rays were produced and a neutron was captured by Cadmium, the existence of this particle was inferred. Can you tell which particle was it?

• A. The neutron
• B. The anti-neutrino
• C. The proton
• D. The electron

Answer 1

The correct option is B The anti-neutrino

In Cowan-Reines experiment neutrinos created in a nuclear reactor produced neutrons and positrons. The positrons annihilate with electron but the two gamma rays that anti-neutrino produced were detectable. The coincidence of both events positron annihilation and neutron capture gives us the idea of anti-neutrino interaction. So, the particle here is anti-neutrino.