Using e+e- → Λ+cΛ-c production from a 567 pb-1 data sample collected by BESIII at 4.6 GeV, a full angular analysis is carried out simultaneously on the four decay modes of Λ+c → pK0S, Λπ+, Σ+π0, and Σ0π+. For the first time, the Λ+c transverse polarization is studied in unpolarized e+e- collisions, where a nonzero effect is observed with a statistical significance of 2.1σ. The decay asymmetry parameters of the Λ+c weak hadronic decays into pK0S, Λπ+, Σ+π0 and Σ0π+ are measured to be 0.18 ± 0.43(stat) ± 0.14(syst), -0.80 ± 0.11(stat) ± 0.02(syst), -0.57 ± 0.10(stat) ± 0.07(syst), and -0.73 ± 0.17(stat) ± 0.07(syst), respectively. In comparison with previous results, the measurements for the Λπ+ and Σ+π0 modes are consistent but with improved precision, while the parameters for the pK0S and Σ0π+ modes are measured for the first time.
- NONLEPTONIC DECAYS