Speaker
Ms
Oksu Seon
(Nagoya University)
Description
In the Standard Model, lepton-number-violating decays such as $B^+ \to D^- \ell^+ \ell^+$ is strictly forbidden, but they are allowed if there exist Majorana-type neutrinos. In this poster, we report a first search for $B^+ \to D^- \ell^+ \ell^+$ ($\ell = e$ or $\mu$) decays with 772$\times 10^{-6}$ $B \bar{B}$ pairs produced by energy-asymmetric $e^+ e^-$ collision at KEKB accelerator and recorded by the Belle detector. We measure no events in signal region and obtain upper limits of branching fraction in the order of $10^{-6}$ at the 90\% C.L.
Author
Ms
Oksu Seon
(Nagoya University)
