Charged-to-neutral meson yield ratio at $\psi(3770)$ and $\Upsilon(4S)$ revisited

TL;DR

This paper revisits the charged-to-neutral meson yield ratios at the $_77$ and $_S$ peaks, highlighting deviations from theoretical estimates and discussing implications for heavy meson structure and interactions.

Contribution

It introduces a combined analysis of meson yield ratios at different energy peaks, considering form factors and strong interactions, to better understand heavy meson structure.

Findings

Significant deviation of measured ratios from simple theoretical estimates.

Possible compatibility of $D$ and $B$ meson data with heavy quark symmetry.

Insights into meson structure involving form factors and strong interactions.

Abstract

The recent precision measurement of the relative yield of $D^+D^-$ and $D^0 \bar D^0$ meson pairs at the $\psi(3770)$ peak in $e^+e^-$ annihilation is about 3.7 sigma away from a straightforward theoretical estimate. It is argued that combined with an even more significant deviation of similar ratio for the $B$ mesons at the $\Upsilon(4S)$ peak, this provides an insight into the structure of heavy mesons and requires both a form factor, corresponding to their finite `size', and a strong interaction between the mesons mesons in the isovector state $I^G(J^P) = 1^+(1^-)$. It is also argued that the data for the $D$ and $B$ mesons are possibly compatible with the heavy quark limit of the same meson-antimeson strong interaction in both systems.