Hadronic Charm Decays: An Experimental Review

The lightest open charm mesons — the D0, D, and Ds — decay through the weak interaction, and the majority of their decays are to final states containing only hadrons. These mesons and their hadronic decays lie at an intersection of weak and strong physics: the easiest detection of charmed states for flavor physics is through hadronic decays with large rates and simple topologies, while the decay processes themselves provide important information on hadronic spectroscopy and strong interactions. Four groups of measurements are discussed here. Two of them, absolute branching fractions of D mesons and strong phases in hadronic decays, are important for allowing precision studies of the CKM matrix and other physics to reduce systematic uncertainties. The other two, the studies of twoand three-body D decay amplitudes, shed light on how long distance hadronic physics affects the visible results of short-distance weak processes.