Measurements of weak decay asymmetries of Λc+ → pKs0, Λπ+, Σ+π0, and Σ0π

Using e+e− → Λc+Λ¯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 Λc+ → pKS0, Λπ+, Σ+π0, and Σ0π+. For the first time, the Λc+ 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 Λc+ weak hadronic decays into pKS0, 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 pKS0 and Σ0π+ modes are measured for the first time.