Observation of two excited charmed baryons decaying into Lambda(+)(c)pi(+/-)

Abstract

Using data recorded by the CLEO-II detector at CESR, we report evidence of a pair of excited charmed baryons, one decaying into Lambda(c)(+)pi(+)2 and the other into Lambda(c)(+)pi(-). The doubly charged state has a measured mass difference M(Lambda(c)(+)pi(+)) - M(Lambda(c)(+)) of 234.5 +/- 1.1 +/- 0.8 MeV/c(2) and a width of 17.9(-3.2)(+3.8) +/- 4.0 MeV/c(2), and the neutral state has a measured mass difference M(Lambda(c)(+)pi(-)) - M(Lambda(c)(+)) of 232.6 +/- 1.0 +/- 0.8 MeV/c(2) and a width of 13.0(-3.0)(+3.7) +/- 4.0 MeV/c(2). We interpret these data as evidence of the Sigma(c)8(++) and Sigma c*(0), the spin 3/2(+) excitations of the Sigma(c) baryons.