Question

How does weak force cause beta decay?

Answer 1

The weak force causes beta decay through interactions with `W^+`, `W^-`, and `Z` bosons.

Explanation:

The weak interaction, or weak force, allows quarks to change flavor. It's important because nearly all of the atoms that were formed after the big bang were hydrogen atoms, which are simply protons. Without the weak force, there would not be enough neutrons to hold together most of the atoms on the periodic table!

Protons and neutrons are made of even smaller particles called quarks, which come in many different flavors. Specifically, a proton is made of two "up" quarks and one "down" quark. Similarly, a neutron is made of two "down" quarks and one "up" quark.

Sometimes, an atom would have a slightly lower energy if only one of its protons were a neutron, or vice versa. This can be achieved by allowing one of the quarks to "flip." For example, one of the "down" quarks in a neutron may "flip" to an "up" quark. The negative charge is carried away by a `W^-` boson, which rapidly decays into an electron and anti-neutrino.

The opposite reaction can happen to a proton, where one of the "up" quarks flips to a "down" quark. This time, a `W^+` boson is emitted, and decays into a positron and neutrino. For either of these events to occur, the final energy of the atom should be less than the initial energy.