Weak Interaction – Weak Force


Tweak and electromagnetic interactionhe weak interaction responsible for some nuclear phenomena such as beta decay, which can be understood in terms of the weak force operating on the quarks within the neutron. One of two down quarks changes into an up quark by emitting a W boson (carries away a negative charge). The W boson then decays into a beta particle and an antineutrino. This process is equivalent to the process, in which a neutrino interacts with a neutron.


weak interaction - weak force

Electroweak Interaction

Although weak force is considered one of the four fundamental forces, at high energy the weak force and electromagnetic force are unified as a single electroweak force. The unification energy is on the order of 100 GeV.  At low energies electromagnetic and weak interaction appear to be very different. Electroweak theory is very important for modern cosmology. In the history of the universe, during the quark epoch (shortly after the Big Bang) the unified force broke into the two separate forces as the universe cooled.

For contributions to the unification of the weak and electromagnetic interaction between elementary particles, Abdus Salam, Sheldon Glashow and Steven Weinberg were awarded the 1979 Nobel Prize in Physics.

Nuclear and Reactor Physics:

Advanced Reactor Physics:


See above:

Fundamental Interactions