Speaker
Xian-Wei Kang
(IAS and IKP, Forschungszentrum Jülich)
Description
The Cabibbo-Kobayashi-Maskawa matrix element |Vub| is not well determined yet. It can be extracted from both inclusive or exclusive decays, like B → ρ(π)l¯νl. However, the exclusive determination from B → ρl¯νl, in particular, suffers from a large model dependence. In this talk, I will elaborate our proposal [1]: extracting |Vub| from the four- body semileptonic decay B → ππl¯νl, where the form factors for the pion-pion system are treated in dispersion theory. This is a model-independent approach that takes into account the ππ rescattering effects, as well as the effect of the ρ meson. We demonstrate that both finite-width effects of the ρ meson as well as scalar ππ contributions can be considered completely in this way.
References
X.-W. Kang, B. Kubis, C. Hanhart and U.-G. Meißner, Phys. Rev. D 89, 053015 (2014).
Primary author
Xian-Wei Kang
(IAS and IKP, Forschungszentrum Jülich)
Co-authors
Prof.
Bastian Kubis
(HISKP, Bonn University)
Prof.
Christoph Hanhart
(IAS and IKP, Forschungszentrum)
Prof.
Ulf-G. Meißner
(HISKP and BCTP, Bonn University; IAS and IKP, Forschungszentrum Jülich)
