Observation of an excited state of the ${\mathrm{\Lambda }}_{\mathit{c}}^{+}$ baryon

An observation of an excited ${\mathrm{\Lambda }}_{\mathit{c}}^{+\mathrm{*}}$ baryon decaying to ${\mathrm{\Lambda }}_{\mathit{c}}^{+}$${\mathrm{\pi }}^{+}$${\mathrm{\pi }}^{\mathrm{-}}$, with ${\mathrm{\Lambda }}_{\mathit{c}}^{+}$→${\mathit{pK}}^{\mathrm{-}}$${\mathrm{\pi }}^{+}$, is presented. We reconstruct 39.7±8.7${\mathrm{\Lambda }}_{\mathit{c}}^{+\mathrm{*}}$ baryons with a mass of 340.4±0.6±0.3 MeV/${\mathit{c}}^2$ above the ${\mathrm{\Lambda }}_{\mathit{c}}^{+}$ mass. The upper limit on the resonant branching ratio is B(${\mathrm{\Lambda }}_{\mathit{c}}^{+\mathrm{*}}$→${\mathrm{\Sigma }}_{\mathit{c}}$${\mathrm{\pi }}^{\pm }$)/B(${\mathrm{\Lambda }}_{\mathit{c}}^{+\mathrm{*}}$→${\mathrm{\Lambda }}_{\mathit{c}}^{+}$ ${\mathrm{\pi }}^{+}$${\mathrm{\pi }}^{\mathrm{-}}$)<36% at the 90% confidence level.