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

Abstract: We present a study of excited charm-strange baryon states produced in $e<sup>+e<sup>-$ annihilations at or near a center-of-mass energy of $10.58\mathrm{Ge\kern -0.1em V}$, in a data sample with an integrated luminosity of $384 fb<sup>{-1}$ recorded with the BABAR detector at the PEP-II $e<sup>+e<sup>-$ storage rings at the Stanford Linear Accelerator Center. We study strong decays of charm-strange baryons to $$\Lambda_c^{+K^{0_{\scriptscriptstyle}} S}$$, $\Lambda_c<sup>+K<sup>-$, $\Lambda_c<sup>+K<sup>-\pi<sup>+$, $$\Lambda_c^{+K^{0_{\scriptscriptstyle}} S}\pi<sup>-$$, $$\Lambda_c^{+K^{0_{\scriptscriptstyle}} S}\pi<sup>-\pi<sup>+$$, and $\Lambda_c<sup>+K<sup>-\pi<sup>+\pi<sup>-$. This study confirms the existence of the states $\Xi_c(2980)<sup>+$, $\Xi_c(3077)<sup>+$, and $\Xi_c(3077)<sup>0$, with a more accurate determination of the $\Xi_c(2980)<sup>+$ mass and width. We also present evidence for two new states, $\Xi_c(3055)<sup>+$ and $\Xi_c(3123)<sup>+$, decaying through the intermediate resonant modes $\Sigma_c(2455)<sup>{++}K<sup>-$ and $\Sigma_c(2520)<sup>{++}K<sup>-$, 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.