Orateur
M.
Andreas Heller
(KIT)
Description
The semileptonic decay $B^+ \to \ell^+ \nu_\ell \gamma$ with $\ell^+ = e^+, \mu^+$ allows for the measurement of $\lambda_B$, which is the first moment of the $B$ meson distribution amplitude. This parameter is needed for the calculation of charmless hadronic $B$ decays in the QCD factorization scheme. The analysis is carried out with the full Belle data sample of $772\,\times 10^6 B \bar{B}$ pairs. One of the $B$ mesons is reconstructed in a hadronic decay channel and its momentum is used to compute the squared missing mass in the decay of the second signal-side $B$ meson. After an efficient signal selection a neural network is trained to separate signal and the main background $B^+ \to \ell^+ \nu_\ell \pi^0$. The signal is extracted in a fit to the squared missing mass in bins of the network output and a limit on the branching fraction is obtained which is the strongest to date.
Auteur principal
M.
Andreas Heller
(KIT)
Co-auteurs
Dr
Anze Zupanc
(Jozef Stefan Institute)
Dr
Martin Heck
(KIT)
Prof.
Michael Feindt
(KIT)
Dr
Pablo Goldenzweig
(KIT)
Dr
Thomas Kuhr
(KIT)
