Definition
A kappa-meson is just another name for a kaon, a type of subatomic particle. It's a meson made up of a quark and an antiquark. Think of it as a specific model of car – a 'kappa-meson' might be the specific name for a base model. Kappa-mesons are unstable and decay into other particles quickly. They are essential for studying fundamental forces and symmetries in particle physics.