# Abstract/Details

## Observation of several new charmed-strange baryon states at CESR-CLEO II

1998 1998

### Abstract (summary)

Using data collected by the CLEO II detector at CESR operating at the $\Upsilon(4S)$ resonance in the energy region around 10.58 GeV, we present the evidence of eight new charmed-strange baryon states. We first observe strong signals in two narrow states decaying into $\Xi\sbsp{c}{+}\gamma$ and $\Xi\sbsp{c}{0}\gamma.$ We associate the observed signals with the ground state $J\sp{P} = {1\over2}\sp+\ \Xi\sbsp{c}{+}\sp\prime$ (c$\{$su$\}$) and the $\Xi\sbsp{c}{0}\sp\prime$ (c$\{$sd$\}$) states with the $M(\Xi\sbsp{c}{+}\sp\prime)-M(\Xi\sbsp{c}{+})$ mass difference of $108.0\pm1.3\pm2.5$ MeV/c$\sp2$ and the $M(\Xi\sbsp{c}{0}\sp\prime)-M(\Xi\sbsp{c}{0})$ mass difference of $110.3\pm1.1\pm2.5$ MeV/c$\sp2,$ respectively. Next we observe strong signals in two narrow states decaying into $\Xi\sbsp{c}{+}\pi\sp-$ and $\Xi\sbsp{c}{0}\pi\sp+.$ We associate the observed signals with the ground state $J\sp{P} = {3\over2}\sp+\ \Xi\sbsp{c}{*}\sp0\ \rm(\{c\{sd\}\})$ and the $\Xi\sbsp{c}{*}\sp+\ \rm(\{c\{su\}\})$ states with the $M(\Xi\sbsp{c}{*}\sp0{-}M(\Xi\sbsp{c}{+})$ mass difference of $177.5\pm0.7\pm0.1$ MeV/c$\sp2$ and the $M(\Xi\sbsp{c}{*}\sp+){-}M(\Xi\sbsp{c}{0})$ mass difference of $174.0\pm1.0\pm1.0$ MeV/c$\sp2,$ respectively. We also observe small, but clean signals in two states decaying into $\Xi\sbsp{c}{*}\sp0\pi\sp+$ and $\Xi\sbsp{c}{*}\sp+\pi\sp-.$ We associate the observed signals with the lowest lying orbitally excited P-Wave $J\sp{P} = {3\over2}\sp-$ (L = 1) $\Xi\sbsp{c1}{**}\rm\sp+(\lbrack c\lbrack su\rbrack\rbrack)$ and $\Xi\sbsp{c1}{**0}(\lbrack c\lbrack sd\rbrack\rbrack)$ states with the $M(\Xi\sbsp{c1}{**}\sp+){-}M(\Xi\sbsp{c}{+})$ mass difference of $349.0\pm0.9\pm1.0$ MeV/c$\sp2$ and the $M(\Xi\sbsp{c1}{**}\sp0){-}M(\Xi\sbsp{c}{0})$ mass difference of $350.2\pm1.2\pm2.0$ MeV/c$\sp2.$ Finally, we also observe small but clean signals in two states decaying into $\Xi\sbsp{c}{+}\sp\prime\pi\sp-$ and $\Xi\sbsp{c}{0}\sp\prime\pi\sp+$. We associate the observed signals with the lowest lying orbitally excited P-Wave $J\sp{P} = {1\over2}\sp-$ (L = 1) $\Xi\sbsp{c1}{**}\sp0(\lbrack c\lbrack sd\rbrack\rbrack$ and $\Xi\sbsp{c1}{**}\sp+(\lbrack c\lbrack su\rbrack\rbrack)$ states with the $M(\Xi\sbsp{c1}{**}\sp0) -M(\Xi\sbsp{c}{+})$ mass difference of 304.8 $\pm$ 2.1 $\pm$ 2.0 MeV/c$\sp2$ and the $M(\Xi\sbsp{c1}{**}\sp+)-M(\Xi\sbsp{c}{0})$ mass difference of 304.0 $\pm$ 1.8 $\pm$ 2.0 MeV/c$\sp2.$