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

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