Charmed-baryon interpretation ofΛ¯π−π−π+andΛ¯π−π−π+π±peaks

Abstract

The $\overline{\Lambda }3\pi \mathrm{}\left(2250\right)\mathrm{}$ and $\overline{\Lambda }4\pi \mathrm{}\left(2500\right)\mathrm{}$ peaks recently discovered in photoproduction are interpreted as charmed antibaryons. Specifically it is suggested that the $\overline{\Lambda }3\pi \mathrm{}\left(2250\right)\mathrm{}$ is the charmed analog of $\Lambda \mathrm{}\left(1115\right)\mathrm{}$ and decays weakly. Quantum-number and spin-parity assignments are discussed briefly. We give isospin relations and predictions for the mean multiplicity of nonleptonic decay products, with special attention to channels detectable in existing experiments. A strategy for studying the dynamics of multibody nonleptonic decays is outlined and an interesting soft-pion theorem is recalled. Semileptonic decays are mentioned in passing. The $\overline{\Lambda }4\pi \mathrm{}\left(2500\right)\mathrm{}$ is interpreted as an amalgam of the charmed analogs of $\Sigma \mathrm{}\left(1192\right)\mathrm{}$ and ${Y_1}^{*}\mathrm{}\left(1385\right)\mathrm{}$; the shape of its two-peak structure is deduced. Prospects for the observation of additional charmed baryons are considered.