Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025
Definition
Baryon number is a quantum number representing the difference between the number of baryons and antibaryons in a system. It is conserved in most particle interactions, meaning the total baryon number remains constant.
5 Must Know Facts For Your Next Test
Baryon number is defined as $B = \frac{1}{3}(n_q - n_{\bar{q}})$, where $n_q$ is the number of quarks and $n_{\bar{q}}$ is the number of antiquarks.
Protons and neutrons each have a baryon number of +1.
Antiprotons and antineutrons each have a baryon number of -1.
In any nuclear reaction or particle decay, the total baryon number before and after the process must be equal.