https://doi.org/10.1140/epjc/s10052-026-15758-1
Regular Article - Theoretical Physics
Dispersive analysis of D- and B-meson form factors with chiral and heavy-quark constraints
1
Helmholtz-Institut für Strahlen- und Kernphysik (Theorie) and Bethe Center for Theoretical Physics, Universität Bonn, 53115, Bonn, Germany
2
Institutionen för fysik och astronomi, Uppsala universitet, Box 516, 75120, Uppsala, Sweden
a
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Received:
13
March
2026
Accepted:
24
April
2026
Published online:
31
May
2026
Abstract
We analyze the isovector vector form factors of 
and 
mesons at low energies. We employ all constraints due to chiral and heavy-quark symmetry, and include the physics of resonant pion–pion rescattering in a model-independent way, using dispersion theory. Special attention is paid to the analytic properties of these form factors, which include anomalous thresholds due to triangle diagrams that are located on the physical Riemann sheets in some of the form factors. We extract the couplings of the 
resonance to all these heavy mesons by determining the appropriate pole residues.
© The Author(s) 2026
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