English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We study the radiative decays $h_{c}\rightarrow\gamma\eta^{(\prime)}$ in theframework of perturbative QCD and evaluate analytically the one-loop integralswith the light quark masses kept. Interestingly, the branching ratios$\mathcal{B}(h_{c}\rightarrow\gamma\eta^{(\prime)})$ are insensitive to boththe light quark masses and the shapes of $\eta^{(\prime)}$ distributionamplitudes. And it is noticed that the contribution of the gluonic content of$\eta^{(\prime)}$ is almost equal to that of the quark-antiquark content of$\eta^{(\prime)}$ in the radiative decays $h_{c} \rightarrow\gamma\eta^{(\prime)}$. By employing the ratio$R_{h_{c}}=\mathcal{B}(h_{c}\rightarrow\gamma\eta)/\mathcal{B}(h_{c}\rightarrow\gamma\eta^{\prime})$,we extract the mixing angle $\phi=33.8^{\circ}\pm2.5^{\circ}$, which is inclear disagreement with the Feldmann-Kroll-Stech result$\phi=39.0^{\circ}\pm1.6^{\circ}$ extracted from the ratio $R_{J/\psi}$ withnonperturbative matrix elements $\langle 0\midG^{a}_{\mu\nu}\tilde{G}^{a,\mu\nu}\mid\eta^{(\prime)}\rangle$, but inconsistent with $\phi=33.5^{\circ}\pm0.9^{\circ}$ extracted from the asymptoticlimit of the $\gamma^{\ast}\gamma-\eta^{\prime}$ transition form factor and$\phi=33.9^{\circ}\pm0.6^{\circ}$ extracted from $R_{J/\psi}$ in perturbativeQCD. We also briefly discuss possible reasons for the difference in thedeterminations of the mixing angle.

Radiative decays of $h_{c}$ to the light mesons $\eta^{(\prime)}$: A perturbative QCD calculation