Light-Cone Sum Rules for the $D_{(s)}\rightarrow \eta^{(\prime)} l \nu_l$ Form Factor

TL;DR

This paper improves light-cone sum rule calculations for $D$ and $D_s$ decays into $\

Contribution

It introduces an enhanced analysis method to better determine the gluonic content of the $\

Findings

Decays can help measure the gluonic contribution of $\

Provides predictions for branching ratios of B decays involving $\

Suggests future experiments can test these theoretical insights.

Abstract

We present an improved light-cone sum rule analysis of the decay form factors of $D$ and $D_s$ into $\eta$ and $\eta^{\prime}$ and argue that these decays offer a very promissing possibility to determine the leading Fock-state gluonic contribution of the $\eta'$ at future experimental facilities as FAIR or Super-KEKB. We also give the corresponding branching ratios for B decays.