Two-Body B Meson Decays to $\eta$ and $\eta^{'}$ -- Observation of $B\to \eta${'}K$

TL;DR

This paper reports the first observation of B meson decays to eta' K with measured branching fractions, providing new experimental data to inform theoretical models of these decay processes.

Contribution

The paper presents the first observation and measurement of B -> eta' K decays, along with upper limits on related decay modes, advancing understanding of B meson decay channels.

Findings

Observed B -> eta' K decays with specific branching fractions.

Set upper limits on 17 related decay modes.

Constrained theoretical models of B meson decays.

Abstract

In a sample of 6.6 million produced B mesons we have observed decays B -> eta' K, with branching fractions BR(B+ -> eta' K+ = 6.5 +1.5 -1.4 +- 0.9) x $10^{-5}$ and BR(B0 -> eta' K0 = 4.7 +2.7 -2.0 +- 0.9) x $10^{-5}$. We have searched with comparable sensitivity for 17 related decays to final states containing an eta or eta' meson accompanied by a single particle or low-lying resonance. Our upper limits for these constrain theoretical interpretations of the B -> eta' K signal.