Using the entire data sample of $980{\mathrm{fb}}^{-1}$ collected at or near the $\mathrm{\Upsilon }(4S)$ resonance with the Belle detector operating at the KEKB asymmetric-energy $e^{+}{e}^{-}$ collider, we report the measurement of the mass, width, and the branching ratios of the ${\mathrm{\Lambda }}_c(2625{)}^{+}$ charmed baryon. The mass difference between ${\mathrm{\Lambda }}_c(2625{)}^{+}$ and ${\mathrm{\Lambda }}_c^{+}$ is measured to be $M({\mathrm{\Lambda }}_c(2625{)}^{+})-M({\mathrm{\Lambda }}_c^{+})=341.518\pm 0.006\pm 0.049\mathrm{MeV}/c^2$. The upper limit on the width is measured to be $\mathrm{\Gamma }({\mathrm{\Lambda }}_c(2625{)}^{+})<0.52\mathrm{MeV}/c^2$ at 90% confidence level. Based on a full Dalitz plot fit, branching ratios with respect to the mode ${\mathrm{\Lambda }}_c(2625{)}^{+}\to {\mathrm{\Lambda }}_c^{+}{\pi }^{+}{\pi }^{-}$ are measured to be $\frac{\mathcal{B}({\mathrm{\Lambda }}_c(2625{)}^{+}\to {\mathrm{\Sigma }}_c^0{\pi }^{+})}{\mathcal{B}({\mathrm{\Lambda }}_c(2625{)}^{+}\to {\mathrm{\Lambda }}_c^{+}{\pi }^{+}{\pi }^{-})}=(5.19\pm 0.23\pm 0.40)\%$ and $\frac{\mathcal{B}({\mathrm{\Lambda }}_c(2625{)}^{+}\to {\mathrm{\Sigma }}_c^{++}{\pi }^{-})}{\mathcal{B}({\mathrm{\Lambda }}_c(2625{)}^{+}\to {\mathrm{\Lambda }}_c^{+}{\pi }^{+}{\pi }^{-})}=(5.13\pm 0.26\pm 0.32)\%$, where the first and second uncertainties are statistical and systematic, respectively. These measurements can be used to further constrain the parameters of the underlying theoretical models.

• Received 13 December 2022
• Accepted 20 January 2023

DOI:https://doi.org/10.1103/PhysRevD.107.032008

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Published by the American Physical Society