Evidence of New States Decaying into $Ξ_{c}^{*}π$

Abstract

Using data recorded by the CLEO II detector at CESR, we report evidence for two new charmed baryons, one decaying into $Ξ_c^+π^+π^-$ via an intermediate $Ξ_c^{*0}$, and its isospin partner decaying into $Ξ_c^0π^+π^-$ via an intermediate $Ξ_c^{*+}$. We measure the mass differences of the two states to be $M(Ξ_c^+π^+π^-)-M(Ξ_c^+)=$ $348.6\pm0.6\pm1.0$ MeV, and $M(Ξ_c^0π^+π^-)-M(Ξ_c^0)=$ $347.2\pm0.7\pm2.0$ MeV. We interpret these new states as the $J^P = {3 \over{2}}^- $ $Ξ_{c1}$ particles, the charmed-strange analogues of the $Λ_{c1}^+(2625)$.

9 pages postscript, also available through http://w4.lns.cornell.edu/public/CLNS