Speaker
Dr
Vadim Baru
(HISKP, Bonn University)
Description
The experimental line shapes available in the $B\bar{B^{\ast}}$, $B^{*}\bar{B^{\ast}}$, $h_b(1P)\pi$ and $h_b(2P)\pi$ channels are analysed using a theoretical EFT-based framework manifestly consistent with unitarity and analyticity. The line shapes are calculated using a system of coupled channel integral equations with the potential consisting of the one-pion and one-eta meson exchange interactions from the lightest Goldstone boson octet as well as of several contact terms at leading and subleading orders which are adjusted to minimise the overall chi squared. The pole positions of the $Z_b(10610)$ and $Z_b(10650)$ are extracted for the best fits corresponding to chi squared of the order of one. The role of the long and intermediate range pion and eta dynamics, as well as of the effects violating heavy quark spin symmetry, is discussed. Insights for the corresponding charmonium-like states $Z_c$’s are considered.
Primary author
Dr
Vadim Baru
(HISKP, Bonn University)
Co-authors
Dr
Alexey Nefediev
(Lebedev Physical Institute)
Dr
Arseniy Filin
(Ruhr-University Bochum)
Dr
Christoph Hanhart
(FZ-Juelich)
Dr
Qian Wang
(HISKP, University of Bonn)
