Charmonia Production in $W\to (c\bar{c}) D_{s}^{(*)}$ Decays

TL;DR

This paper analyzes the production of charmonium states in specific W boson decays using NRQCD and light-cone models, providing predictions for branching fractions and discussing the significance of color-octet contributions.

Contribution

It offers the first detailed comparison of NRQCD and light-cone approaches for these decays, highlighting the importance of internal quark effects and color-octet contributions.

Findings

Branching fractions are around 10^{-11}.

Light-cone results are approximately four times larger than NRQCD predictions.

Color-octet contributions could be comparable to color-singlet results.

Abstract

In the presented paper production of charmonium state $\mathcal{Q}$ in exclusive $W\to\mathcal{Q} D_{s}^{(*)}$ decays is analyzed in the framework of both leading order Nonrelativistic Quantum Chromodynamics (NRQCD) and light-cone expansion (LC) models. Analytical and numerical predictions for the branching fractions of these decays in both approaches are given. The typical value of the branching fractions is $\sim 10^{-11}$ and it turns out the LC results are about 4 times lager than NRQCD ones, so the effect of internal quark should be taken into account. Some estimates of color-octet contributions are presented and it is shown, that these contributions could be comparable with color-singlet results.