Author: Emily Conover / Source: Science News Nuclear physicist Evangeline Downie hadn’t planned to study one of the thorniest puzzles of the proton. But when opportunity knocked, Downie couldn’t say no. “It’s the proton,” she exclaims. The mysteries that still swirl around this jewel of the

Ds3*(2860)ˉ is a meson that contains a charm anti-quark and a strange quark. The subscript 3 denotes that it has spin 3, while the number 2860 in parentheses is the mass of the particle in the units of MeV/c2. The value of 2,860 MeV/c2 corresponds to approximately 3 times the mass of the proton.