Shannon entropy and hadronic decays
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 $S(i) =-\sum_{f}BR_{(i\longrightarrow f)}\log BR_{(i\longrightarrow f)}$ that 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.