Search for B -> h(*) nu nubar with the full Belle Y(4S) data sample

TL;DR

This study searches for rare B meson decays involving neutrinos and mesons using the full Belle dataset, setting the most restrictive upper limits to date on several decay modes.

Contribution

First comprehensive search for B -> h(*) nu nubar decays using the full Belle Y(4S) data, establishing the most stringent upper limits on these processes.

Findings

No significant signals observed.

Set new upper limits on branching fractions.

Most restrictive limits to date for several decay modes.

Abstract

We report a search for the rare decays B -> h(*) nu nubar, where h(*) stands for K+, Ks0, K*+, K*0, pi+, pi0, rho+, rho0 and phi. The results are obtained from a 711 fb-1 data sample that contains 772 million BB pairs collected at the Y(4S) resonance with the Belle detector at the KEKB e+e- collider. We search for signal candidates by fully reconstructing a hadronic decay of the accompanying B meson and requiring a single h(*) meson left on the signal side. No significant signal is observed and we set upper limits on the branching fractions at 90% confidence level. The measurements of B+ -> K*+ nu nubar, B+ -> pi+ nu nubar, B0 -> pi0 nu nubar and B0 -> rho^0 nu nubar provide the world's currently most restrictive limits.