A model independent description of decays
arXiv:2311.00864
Abstract
We introduce a new parameterization of form factors using a partial-wave expansion and derive bounds on the series coefficients using analyticity and unitarity. This is the first generalization of the model-independent formalism developed by Boyd, Grinstein, and Lebed for to semileptonic decays with multi-hadron final states, and enables data-driven form factor determinations with robust, systematically-improvable uncertainties. Using this formalism, we extract the form-factor parameters for decays in a model-independent way from fits of data from the Belle Experiment, and, for the first time, study the two-pole structure in the S-wave in semileptonic decays employing lineshapes from unitarized chiral perturbation theory.
13 pages, 4 wonderful figures; Extended supplementary material, results and conclusions unchanged; Version accepted by PRD