Measurement of the Masses and Widths of the $\hat{I}{\pounds }_c(2455{)}^{+}$ and $\hat{I}{\pounds }_c(2520{)}^{+}$ Baryons

Abstract

Using 980 ${\mathrm{fb}}^{-1}$ of data {collected} with the Belle detector operating at the KEKB asymmetric-energy $e^{+}{e}^{-}$ collider, we report the measurements of the masses, and the first measurements of the instrinsic widths, of the $\hat{I}{\pounds }_c(2455{)}^{+}$ and $\hat{I}{\pounds }_c(2520{)}^{+}$ charmed baryons. We find $M(\hat{I}{\pounds }_c(2455{)}^{+})-M(\hat{I}{›}_c^{+})=166.17\pm 0.05_{-0.07}^{+0.16}\mathrm{MeV}/c^2$, $\hat{I}“(\hat{I}{\pounds }_c(2455{)}^{+})=2.3\pm 0.3\pm 0.3MeV/{\mathrm{c}}^2$, $M(\hat{I}{\pounds }_c(2520{)}^{+})-M(\hat{I}{›}_c^{+})=230.9\pm 0.5_{-0.1}^{+0.5}\mathrm{MeV}/c^2$, and $\hat{I}“(\hat{I}{\pounds }_c(2520{)}^{+})=17.2_{-2.1-0.7}^{+2.3+3.1}\mathrm{MeV}/c^2$, where the uncertainties are statistical and systematic, respectively. These measurements can be used to test models of the underlying quark structure of the $\hat{I}{\pounds }_c$ states.