Evidence of New States Decaying into Xi_c^{prime} pi


Abstract in English

Using 13.7 fb^{-1} of data recorded by the CLEO detector at CESR, we report preliminary evidence for two new charmed baryons; one decaying into Xi_c^{0prime} pi^+ with the subsequent decay Xi_c^{0prime} to Xi_c^0 gamma, and its isospin partner decaying into Xi_c^{+prime} pi^- followed by Xi_c^{+prime} to Xi_c^+ gamma. We measure the following mass differences for the two states: M(Xi_c^0 gamma pi^+)-M(Xi_c^0)=318.4+-1.5+-2.9 MeV, and M(Xi_c^+ gamma pi^-)-M(Xi_c^+)=323.9+-pm1.4+-pm3.0 MeV. We interpret these new states as the J^P = (1/2)^-1 Xi_{c1} particles, the charmed-strange analogues of the Lambda_{c1}^+(2593).

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