Is There a Light Scalar Boson?

In view of recent theoretical interest in the possibility of a light scalar boson $\phi$ we discuss some of its properties and possible methods for detecting it. Cross sections for its production are typically ${10}^{-8\mathrm{}}$ of competing processes, with the possible exception of $0^{+}$ → $0^{+}$ transitions in nuclei. We also give a general method of determining the mass of a particle from the energy of its decay products alone, which does not seem to be well known.