Strangeness

Definition

Strangeness is a quantum number used to describe the presence of strange quarks in a particle. It is conserved in strong and electromagnetic interactions but not in weak interactions.

5 Must Know Facts For Your Next Test

1. Strangeness is assigned the value of -1 for each strange quark (s) and +1 for each anti-strange quark ($\bar{s}$).
2. The discovery of particles with non-zero strangeness led to the identification of the strange quark.
3. Strange particles, such as kaons and hyperons, are produced in strong interactions but decay via weak interactions where strangeness is not conserved.
4. Strangeness conservation is crucial for understanding particle reactions and decays involving strange quarks.
5. In high-energy physics experiments, observing changes in strangeness helps identify different types of particle interactions.

Review Questions

• What does a strangeness value of -1 indicate about a particle's composition?
• Why is strangeness conserved in strong and electromagnetic interactions but not in weak interactions?
• How did the concept of strangeness contribute to the discovery of the strange quark?

Related terms

Quark: Fundamental particles that combine to form hadrons, such as protons and neutrons. They come in six flavors: up, down, charm, strange, top, and bottom.

Kaon: A type of meson that contains a strange quark or anti-strange quark. Kaons have non-zero strangeness.

Hyperon: A baryon containing one or more strange quarks. Examples include Lambda ($\Lambda$) and Sigma ($\Sigma$) particles.