strange quark

The strange quark is a type of subatomic particle, one of the fundamental building blocks of matter. In 1964, physicists Murray Gell-Mann and George Zweig independently proposed that hadrons, such as protons and neutrons, are composed of smaller particles called quarks.1

Initially, three types of quarks were theorized: up, down, and strange. These quarks possess unusual properties, including fractional electric charges of +2/3e or -1/3e. While direct evidence of isolated quarks has not been found, experiments have confirmed their existence within hadrons. The strange quark has a quantum number called strangeness (S = -1) and is heavier than the up and down quarks. It plays a role in particle interactions governed by the weak force.1