Someone argues: "The baryon has mass while the proton has mass
PHYSICS · Multi-part · Fermi University Physics · Particle Physics & Quantum Fields · Symmetry, groups and the quark model · Symmetry, groups and the quark model
Particle Physics, Ch SU(3) flavour and the hadron multiplets
Problem
Someone argues: "The Δ+ baryon has mass 1232MeV/c2 while the proton has mass 938.3MeV/c2. Such different masses must mean the Δ+ has a different quark content from the proton, probably with a strange quark swapped in."
((a)) State the quark content of the proton and of the Δ+.
((b)) Explain, using the decomposition 3⊗3⊗3=10⊕8⊕8⊕1, how two baryons with the same quark content can belong to different multiplets with different masses.
((c)) Identify the error in the quoted argument.