# What is beta decay in terms of quarks?

Jun 6, 2016

In β-decay, a quark decays into another type of quark, releasing a β particle and a neutrino.

#### Explanation:

Protons and neutrons consist of quarks.

(from quantumpulse.com)

A proton consists of two up quarks and a down quark ($\text{p = uud}$).

In positron (β^+) decay, an up quark changes to a down quark, with the release of a positron and a neutrino.

"u → d" color(white)(l)+ β^+ + ν

The overall result us that a proton becomes a neutron:

"p → n"color(white)(l) + β^+ + ν

A neutron consists of two down quarks and a up quark ($\text{n = ddu}$).

In beta (β^"-") decay, a down quark changes to an up quark, with the release of an electron (β^"-") and an antineutrino.

"d → u"color(white)(l) + β^"-" + bar(ν)

The overall result us that a neutron becomes a proton:

"n → p"color(white)(l) + β^"-" + bar(ν)

In pictures, β-decay looks like this:

(from schoolphysics.co.uk)