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.

How much information is added to the Review of Particle Physics when a new decay branching ratio of a hadron is measured and reported? This is quantifiable by Shannon's information entropythat takes as input the experimental branching ratios (BR) of the decay distribution of particle i. It may be used at two levels, against the distribution of decay-channel probabilities, or against the distribution of individual quantum-state probabilities (integrating the phase space of those states provides the former). We illustrate the concept with some examples.

How much information is added to the Review of Particle Physics when a new decay branching ratio of a hadron is measured and reported? This is quantifiable by Shannon's information entropy. It may be used at two levels, against the distribution of decay-channel probabilities, or against the distribution of individual quantum-state probabilities (integrating the phase space of those states provides the former). We illustrate the concept with some examples.