Exotic particle turns out to be quark molecule

Simulations suggest Lambda (1405) is meson-baryon combo

Like atoms, subatomic particles can link up to form “molecules.” A long-studied subatomic particle called Lambda (1405) is actually a molecule of two tightly knit particles, researchers report in the April 3 Physical Review Letters. The study reveals a novel arrangement of matter made of quarks, the fundamental constituents of Lambda (1405) and every nucleus of every atom in the universe.