Final answer:
The quark structure of a positive sigma (Σ+) baryon is uus, with two up quarks and one strange quark. Its decay process and excited state relative to the lambda-zero particle are indicative of its quark composition and energy levels.
Step-by-step explanation:
The structure of a positive sigma (Σ+) baryon consists of two up quarks (u) and one strange quark (s), which is denoted as uus. The positive sigma baryon is part of the family of particles known as baryons, which are hadrons composed of three quarks. The quarks inside baryons, such as the positive sigma baryon, are bound together by the strong force, mediated by gluons.
The decay of the sigma-zero particle (Σ0 → A0 + y) implies that the Σ0 is an excited state of the lambda-zero (A0) particle because it releases energy to reach a more stable state with lower energy. The decay result reflects the differences in energy levels between quark configurations within these particles. The lambda-zero particle's quark composition is uds, which is very similar to the Σ0 with uds quarks as well, but with the strange quark at a lower energy state.
The proton p is composed of uud quarks, and a neutron n is formed from udd quarks. These compositions demonstrate the importance of quark content in determining the properties of baryons such as charge and spin. Furthermore, the decay of particles such as the neutron (ℓ → p + ß– + νe) also illustrates quark flavor change as a mechanism in fundamental particle interactions.