Measurement of the mass and width of the $\hat{I}{›}_c(2625{)}^{+}$ and the branching ratios of $\hat{I}{›}_c(2625{)}^{+}\to \hat{I}{\pounds }_c^0\ddot{I}{€}^{+}$ and $\hat{I}{›}_c(2625{)}^{+}\to \hat{I}{\pounds }_c^{++}\ddot{I}{€}^{-}$

Abstract

Using the entire data sample of $980{\text{fb}}^{-1}$ collected with the Belle detector operating at the KEKB asymmetric-energy collider, we report the measurement of the mass, width, and the relative branching ratios of the $\hat{I}{›}_c(2625{)}^{+}$ charmed baryon. The mass difference between $\hat{I}{›}_c(2625{)}^{+}$ and $\hat{I}{›}_c^{+}$ is measured to be $M(\hat{I}{›}_c(2625{)}^{+})-M(\hat{I}{›}_c^{+})=341.518\pm 0.006\pm 0.049\mathrm{MeV}/c^2$. The upper limit on the width is measured to be $\hat{I}“(\hat{I}{›}_c(2625{)}^{+})<0.52\mathrm{MeV}/{\text{c}}^2$ at 90\% credibility level. Based on a full Dalitz plot fit, branching ratios with respect to the mode $\hat{I}{›}_c(2625{)}^{+}\to \hat{I}{›}_c^{+}\ddot{I}{€}^{+}\ddot{I}{€}^{-}$ are measured to be $\frac{\mathcal{B}(\hat{I}{›}_c(2625{)}^{+}\to \hat{I}{\pounds }_c^0\ddot{I}{€}^{+})}{\mathcal{B}(\hat{I}{›}_c(2625{)}^{+}\to \hat{I}{›}_c^{+}\ddot{I}{€}^{+}\ddot{I}{€}^{-})}=(5.19\pm 0.23\pm 0.40)\%$ and $\frac{\mathcal{B}(\hat{I}{›}_c(2625{)}^{+}\to \hat{I}{\pounds }_c^{++}\ddot{I}{€}^{-})}{\mathcal{B}(\hat{I}{›}_c(2625{)}^{+}\to \hat{I}{›}_c^{+}\ddot{I}{€}^{+}\ddot{I}{€}^{-})}=(5.13\pm 0.26\pm 0.32)\%$. These measurements can be used to further constrain the parameters of the underlying theoretical models.