A Study of Excited Charm-Strange Baryons with Evidence for new Baryons \Xi_c(3055)^+ and \Xi_c(3123)^+

We present a study of excited charm-strange baryon states produced in $e^{+}{e}^{-}$ annihilations at or near a center-of-mass energy of $10.58\mathrm{G}\mathrm{e}\mathrm{V}$, in a data sample with an integrated luminosity of $384f{b}^{-1}$ recorded with the BABAR detector at the PEP-II $e^{+}{e}^{-}$ storage rings at the Stanford Linear Accelerator Center. We study strong decays of charm-strange baryons to $\Lambda_c^+K^0_{\scriptscriptstyle S}$,$\Lambda_c^+K^-$,$\Lambda_c^+K^-\pi^+$,$\Lambda_c^+K^0_{\scriptscriptstyle S}\pi^-$,$\Lambda_c^+K^0_{\scriptscriptstyle S}\pi^-\pi^+$,and$\Lambda_c^+K^-\pi^+\pi^-$\mathrm{.}Thisstudyconfirmstheexistenceofthestates$\Xi_c(2980)^+$,$\Xi_c(3077)^+$,and$\Xi_c(3077)^0$, with a more accurate determination of the ${\mathrm{\Xi }}_c(2980{)}^{+}$ mass and width. We also present evidence for two new states, ${\mathrm{\Xi }}_c(3055{)}^{+}$ and ${\mathrm{\Xi }}_c(3123{)}^{+}$, decaying through the intermediate resonant modes ${\mathrm{\Sigma }}_c(2455{)}^{++}{K}^{-}$ and ${\mathrm{\Sigma }}_c(2520{)}^{++}{K}^{-}$, respectively. For each of these baryons, we measure the yield in each final state, determine the statistical significance, and calculate the product of the production cross-section and branching fractions. We also measure the masses and widths of these excited charm-strange baryons.