Search for B -> h(*) nu nubar Decays at Belle

TL;DR

This paper reports a search for rare B meson decays involving a light meson and neutrinos, setting new upper limits on their branching fractions using Belle data, with no significant signals observed.

Contribution

First comprehensive search for multiple B -> h(*) nu nubar decays, establishing more stringent upper limits and exploring previously unsearched decay modes.

Findings

No significant signals detected.

Set more stringent upper limits on B0 -> K*0 nu nubar and B+ -> K+ nu nubar.

First searches for B0 -> K0 nu nubar, pi0 nu nubar, rho0 nu nubar, phi nu nubar, B+ -> K*+ nu nubar, rho+ nu nubar.

Abstract

We present a search for the rare decays B -> h(*) nu nubar, where h(*) stands for a light meson. A data sample of 535 million BBbar pairs collected with the Belle detector at the KEKB e+e- collider is used. Signal candidates are required to have an accompanying B meson fully reconstructed in a hadronic mode and signal-side particles consistent with a single h(*) meson. No significant signal is observed and we set upper limits on the branching fractions at 90% confidence level. The limits on B0 -> K*0 nu nubar and B+ -> K+ nu nubar decays are more stringent than the previous constraints, while the first searches for B0 -> K0 nu nubar, pi0 nu nubar, rho0 nu nubar, phi nu nubar and B+ -> K*+ nu nubar, rho+ nu nubar are reported.