Extracting the light quark mass ratio m_u/m_d from bottomonia transitions

Abstract

We propose a new method to extract the light quark mass ratio $m_u/m_d$ using the $Υ(4S)\to h_bπ^0(η)$ 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 $Υ(4S)\to h_bη$ is expected to be a nice channel for searching for the $h_b$ state.

4 pages, 1 figure. Version slightly shortened to match the published version in PRL