Partial wave analysis of the charmed baryon hadronic decay ${\Lambda }_{c}^{+}$ → Λπ + π 0

Based on e + e − collision samples corresponding to an integrated luminosity of 4.4 fb −1 collected with the BESIII detector at center-of-mass energies between 4.6 GeV and 4.7 GeV, a partial wave analysis of the charmed baryon hadronic decay ${\Lambda }_{c}^{+}$ → Λπ + π 0 is performed, and the decays ${\Lambda }_{c}^{+}$ → Λρ(770)+ and ${\Lambda }_{c}^{+}$ → Σ(1385)π are studied for the first time. Making use of the world-average branching fraction $B\left({\Lambda }_{c}^{+}\to \Lambda {\pi }^{+}{\pi }^{0}\right)$ , their branching fractions are determined to be $\begin{array}{c}B\left({\Lambda }_{c}^{+}\to \Lambda \rho {\left(770\right)}^{+}\right)=\left(4.06±0.30±0.35±0.23\right)×{10}^{-2},\\ B\left({\Lambda }_{c}^{+}\to \Sigma {\left(1385\right)}^{+}{\pi }^{0}\right)=\left(5.86±0.49±0.52±0.35\right)×{10}^{-3},\\ B\left({\Lambda }_{c}^{+}\to \Sigma {\left(1385\right)}^{0}{\pi }^{+}\right)=\left(6.47±0.59±0.66±0.38\right)×{10}^{-3},\end{array}$ where the first uncertainties are statistical, the second are systematic, and the third are from the uncertainties of the branching fractions $B\left({\Lambda }_{c}^{+}\to \Lambda {\pi }^{+}{\pi }^{0}\right)$ and $B\left(\Sigma \left(1385\right)\to \Lambda \pi \right)$ . In addition, the decay asymmetry parameters are measured to be α Λρ(770)+ = − 0.763 ± 0.053 ± 0.045, ${\alpha }_{\Sigma \left(1385\right)+{\pi }^{0}}=-0.917±0.069±0.056$ , and ${\alpha }_{\Sigma {\left(1385\right)}^{0}{\pi }^{+}}=-0.789±0.098±0.056$ .