Partial wave analysis of the charmed baryon hadronic decay Λc+→ Λπ+π0

Abstract

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 ${\mathrm{\Lambda }}_c^{+}$→ Λπ⁺π⁰ is performed, and the decays ${\mathrm{\Lambda }}_c^{+}$→ Λρ(770)⁺ and ${\mathrm{\Lambda }}_c^{+}$→ Σ(1385)π are studied for the first time. Making use of the world-average branching fraction $\mathcal{B}\left({\mathrm{\Lambda }}_c^{+}\to \mathrm{\Lambda }{\pi }^{+}{\pi }^0\right)$, their branching fractions are determined to be$$\begin{array}{c}\mathcal{B}\left({\mathrm{\Lambda }}_c^{+}\to \mathrm{\Lambda }\rho {\left(770\right)}^{+}\right)=\left(4.06\pm 0.30\pm 0.35\pm 0.23\right)\times {10}^{-2},\\ \mathcal{B}\left({\mathrm{\Lambda }}_c^{+}\to \Sigma {\left(1385\right)}^{+}{\pi }^0\right)=\left(5.86\pm 0.49\pm 0.52\pm 0.35\right)\times {10}^{-3},\\ \mathcal{B}\left({\mathrm{\Lambda }}_c^{+}\to \Sigma {\left(1385\right)}^0{\pi }^{+}\right)=\left(6.47\pm 0.59\pm 0.66\pm 0.38\right)\times {10}^{-3},\end{array}$$where the first uncertainties are statistical, the second are systematic, and the third are from the uncertainties of the branching fractions $\mathcal{B}\left({\mathrm{\Lambda }}_c^{+}\to \Lambda {\pi }^{+}{\pi }^0\right)$ and $\mathcal{B}\left(\mathrm{\Sigma }\left(1385\right)\to \mathrm{\Lambda }\pi \right)$. In addition, the decay asymmetry parameters are measured to be α_Λρ(770)+ =  − 0.763 ± 0.053 ± 0.045, ${\alpha }_{\mathrm{\Sigma }\left(1385\right)+{\pi }^0}=-0.917\pm 0.069\pm 0.056$, and ${\alpha }_{\mathrm{\Sigma }{\left(1385\right)}^0{\pi }^{+}}=-0.789\pm 0.098\pm 0.056$.