Strangeness is a crucial quantum number in particle physics that plays a significant role in determining the stability of particles.

In the realm of particle physics, strangeness is defined as a quantum number that characterizes hadrons—particles that are composed of quarks. Importantly, strangeness is a conserved quantity, meaning its value remains unchanged before and after a particle interaction.

Particles that possess a non-zero strangeness are referred to as strange particles. These strange particles are generally more massive and less stable compared to their counterparts with zero strangeness. They can decay into other particles via the weak force, which governs processes such as radioactive decay.

The discovery of strange particles in the 1950s was pivotal in the formulation of the quark model. This model provides an explanation for the properties of hadrons based on their constituent quarks. According to the quark model, any particle with non-zero strangeness must contain at least one strange quark.

Furthermore, strangeness is vital in the investigation of high-energy collisions, such as those that occur in particle accelerators. By analyzing the production and decay of strange particles, physicists can gain insights into the properties of matter at extreme temperatures and densities, akin to those present in the early universe.