June 29, 2015 to July 3, 2015
Europe/Rome timezone

B_{l4} decays and the extraction of |V_ub|

Jun 29, 2015, 4:40 PM
Aula Magna (Building E, Polo Fibonacci, Pisa)

Aula Magna

Building E, Polo Fibonacci, Pisa

Talk Goldstone Boson Working Group Parallel Session 2 - Goldstone Boson WG


Xian-Wei Kang (IAS and IKP, Forschungszentrum Jülich)


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)


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)

Presentation materials