Logo image
Self-consistent optimization of the z-Expansion for B meson decays
Preprint   Open access

Self-consistent optimization of the z-Expansion for B meson decays

Daniel Simons, Erik Gustafson and Yannick Meurice
ArXiv.org
Cornell University
04/25/2023
DOI: 10.48550/arxiv.2304.13045
url
https://doi.org/10.48550/arXiv.2304.13045View
Preprint (Author's original) This preprint has not been evaluated by subject experts through peer review. Preprints may undergo extensive changes and/or become peer-reviewed journal articles. Open Access

Abstract

We discuss the self-consistency imposed by the analyticity of regular parts of form factors, appearing in the $z$-expansion for semileptonic $B$-meson decays, when fitted in different kinematic regions. Relying on the uniqueness of functions defined by analytic continuation, we propose four metrics which measure the departure from the ideal analytic self-consistency. We illustrate the process using Belle data for $B\rightarrow D\ell \nu_\ell$. For this specific example, the metrics provide consistent indications that some choices (order of truncation, BGL or BCL) made in the form of the $z$-expansion can be optimized. However, other choices ($z$-origin, location of isolated poles and threshold constraints) appear to have very little effect on these metrics. We briefly discuss the implication for optimization of the $z$-expansion for nucleon form factors relevant for neutrino oscillation experiments.

Details

Metrics

12 Record Views
Logo image