2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/194604The contributions to heavy meson mass differences by the strong hyperfine interaction, the light quark masses and the electromagnetic interaction are obtained from the empirical values of the $D$, $D^*$, $B$ and $B^*$ masses by means of a mass formula based on the heavy quark mass expansion. The three different types of contributions are determined with significant accuracy to next to leading order in that expansion.12 pages, 2 figuresHigh Energy Physics - Phenomenologytext