Measurement of branching fractions of ${\mathrm{\Lambda }}_c^{+}$ decays to ${\mathrm{\Sigma }}^{+}\eta$ and ${\mathrm{\Sigma }}^{+}{\eta }^{\mathrm{\prime }}$

By analyzing $e^{+}{e}^{-}$ collision data taken at center-of-mass energies $\sqrt{s}$ between 4.600 and 4.699 GeV with the BESIII detector at the BEPCII collider, corresponding to an integrated luminosity of $4.5\mathrm{f}{\mathrm{b}}^{-1}$, we study the hadronic decays ${\mathrm{\Lambda }}_c^{+}\to {\mathrm{\Sigma }}^{+}\eta$ and ${\mathrm{\Lambda }}_c^{+}\to {\mathrm{\Sigma }}^{+}{\eta }^{\mathrm{\prime }}$ using the single-tag method. The branching fraction ratio of ${\mathrm{\Lambda }}_c^{+}\to {\mathrm{\Sigma }}^{+}\eta$ relative to ${\mathrm{\Lambda }}_c^{+}\to {\mathrm{\Sigma }}^{+}{\pi }^0$ is determined to be $0.305\pm {0.046}_{\mathrm{s}\mathrm{t}\mathrm{a}\mathrm{t}\mathrm{.}}\pm {0.007}_{\mathrm{s}\mathrm{y}\mathrm{s}\mathrm{t}\mathrm{.}}$, and that of ${\mathrm{\Lambda }}_c^{+}\to {\mathrm{\Sigma }}^{+}{\eta }^{\mathrm{\prime }}$ relative to ${\mathrm{\Lambda }}_c^{+}\to {\mathrm{\Sigma }}^{+}\omega$ is $0.336\pm {0.094}_{\mathrm{s}\mathrm{t}\mathrm{a}\mathrm{t}\mathrm{.}}\pm {0.037}_{\mathrm{s}\mathrm{y}\mathrm{s}\mathrm{t}\mathrm{.}}$. The ratio of $\frac{\mathcal{B}({\mathrm{\Lambda }}_c^{+}\to {\mathrm{\Sigma }}^{+}{\eta }^{\mathrm{\prime }})}{\mathcal{B}({\mathrm{\Lambda }}_c^{+}\to {\mathrm{\Sigma }}^{+}\eta )}$ is determined to be $1.73\pm {0.22}_{\mathrm{s}\mathrm{t}\mathrm{a}\mathrm{t}\mathrm{.}}\pm {0.16}_{\mathrm{s}\mathrm{y}\mathrm{s}\mathrm{t}\mathrm{.}}$. These results enrich our knowledge of charmed baryon decays.