Measurements of the masses and widths of the $\hat{I}{\pounds }_c(2455{)}^{0/++}$ and $\hat{I}{\pounds }_c(2520{)}^{0/++}$ baryons

Abstract

We present measurements of the masses and decay widths of the baryonic states $\hat{I}{\pounds }_c(2455{)}^{0/++}$ and $\hat{I}{\pounds }_c(2520{)}^{0/++}$ using a data sample corresponding to an integrated luminosity of 711 fb${}^{-1}$ collected with the Belle detector at the KEKB $e^{+}{e}^{-}$ asymmetric-energy collider operating at the $\hat{I}\yen (4S)$ resonance. We report the mass differences with respect to the $\hat{I}{›}_c^{+}$ baryon $M(\hat{I}{\pounds }_c(2455{)}^0)-M(\hat{I}{›}_c^{+})=167.29\pm 0.01\pm 0.02$ MeV/$c^2$, $M(\hat{I}{\pounds }_c(2455{)}^{++})-M(\hat{I}{›}_c^{+})=167.51\pm 0.01\pm 0.02$ MeV/$c^2$, $M(\hat{I}{\pounds }_c(2520{)}^0)-M(\hat{I}{›}_c^{+})=231.98\pm 0.11\pm 0.04$ MeV/$c^2$, $M(\hat{I}{\pounds }_c(2520{)}^{++})-M(\hat{I}{›}_c^{+})=231.99\pm 0.10\pm 0.02$ MeV/$c^2$, and the decay widths $\hat{I}“(\hat{I}{\pounds }_c(2455{)}^0)=1.76\pm 0.04_{-0.21}^{+0.09}$ MeV/$c^2$, $\hat{I}“(\hat{I}{\pounds }_c(2455{)}^{++})=1.84\pm 0.04_{-0.20}^{+0.07}$ MeV/$c^2$, $\hat{I}“(\hat{I}{\pounds }_c(2520{)}^0)=15.41\pm 0.41_{-0.32}^{+0.20}$ MeV/$c^2$, $\hat{I}“(\hat{I}{\pounds }_c(2520{)}^{++})=14.77\pm 0.25_{-0.30}^{+0.18}$ MeV/$c^2$, where the first uncertainties are statistical and the second are systematic. The isospin mass splittings are measured to be $M(\hat{I}{\pounds }_c(2455{)}^{++})-M(\hat{I}{\pounds }_c(2455{)}^0)=0.22\pm 0.01\pm 0.01$ MeV/$c^2$ and $M(\hat{I}{\pounds }_c(2520{)}^{++})-M(\hat{I}{\pounds }_c(2520{)}^0)=0.01\pm 0.15\pm 0.03$ MeV/$c^2$. These results are the most precise to date.

13 pages, 4 figures, Submitted to PRD(RC)