2023/11/01 by Gustafson, Erik J., Herren, Florian, Van de Water, Ruth S. +2
#FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #High Energy Physics - Lattice (hep-lat) #High Energy Physics - Phenomenology (hep-ph)
paper · doi:10.48550/arxiv.2311.00864
We introduce a new parameterization of B→ D πℓ ν 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 B → D ℓ ν 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 B → D2^∗(→ Dπ) ℓ ν 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 Dπ S-wave in semileptonic decays employing lineshapes from unitarized chiral perturbation theory.