  We deploy Shannon's information entropy to the distribution of branching
fractions in a particle decay. This serves to quantify how important a given
new reported decay channel is, from the point of view of the information that
it adds to the already known ones. Because the entropy is additive, one can
subdivide the set of channels and discuss, for example, how much information
the discovery of a new decay branching would add; or subdivide the decay
distribution down to the level of individual quantum states (which can be
quickly counted by the phase space). We illustrate the concept with some
examples of experimentally known particle decay distributions.
