Extracting the light quark mass ratio m(u)/m(d) from bottomonia transitions.

We propose a new method to extract the light quark mass ratio m(u)/m(d) using the Υ(4S)→h(b)π⁰(η) bottomonia transitions. The decay amplitudes are dominated by the light quark mass differences, and the corrections from other effects are rather small, allowing for a precise extraction. We also discuss how to reduce the theoretical uncertainty with the help of future experiments. As a by-product, we show that the decay Υ(4S)→h(b)η is expected to be a nice channel for searching for the h(b) state.