The scalar-meson to vector-meson mass ratio, due to spontaneous symmetry breakdown, is calculated in the two-loop approximation of massless scalar quantum electrodynamics. Although the effective potential is gauge-dependent, this mass ratio is found to be gauge-independent. This strongly supports the interpretation given by Coleman and Weinberg that the radiative corrections drive the spontaneous symmetry breakdown in this theory. The mass ratio is found to be $\frac{{m_S}^2}{{m_V}^2}=\frac{\frac{3}{2}{e}^2}{4{\pi }^2}-\frac{61}{48}{\left(\frac{e^2}{4{\pi }^2}\right)}^2$, where $e^2$ is the physical coupling constant.

• Received 19 June 1974

DOI:https://doi.org/10.1103/PhysRevD.10.3455