Partial wave analysis of the charmed baryon hadronic decay $\Lambda_c^+\to\Lambda\pi^+\pi^0$

TL;DR

This paper performs a detailed partial wave analysis of the decay $\, ext{Lambda}_c^+ o ext{Lambda} ext{pi}^+ ext{pi}^0$, measuring branching fractions and decay asymmetries for the first time using BESIII data.

Contribution

It introduces the first partial wave analysis of this decay mode and measures branching fractions and asymmetries with improved precision.

Findings

Branching fraction of $ ext{Lambda}_c^+ o ext{Lambda} ho(770)^+$ is approximately 4.06%

Branching fractions for $ ext{Lambda}_c^+ o ext{Sigma}(1385) ext{pi}$ are around 0.6%

Decay asymmetry parameters are measured with uncertainties for the first time.

Abstract

Based on $e^+e^-$ collision samples corresponding to an integrated luminosity of 4.4 $\mbox{fb$^{-1}$}$ collected with the BESIII detector at center-of-mass energies between $4.6\,\,\mathrm{GeV}$ and $4.7\,\,\mathrm{GeV}$, a partial wave analysis of the charmed baryon hadronic decay $\Lambda_c^+\to\Lambda\pi^+\pi^0$ is performed, and the decays $\Lambda_c^+\to\Lambda\rho(770)^{+}$ and $\Lambda_c^+\to\Sigma(1385)\pi$ are studied for the first time. Making use of the world-average branching fraction $\mathcal{B}(\Lambda_c^+\to\Lambda\pi^+\pi^0)$, their branching fractions are determined to be \begin{eqnarray*} \begin{aligned} \mathcal{B}(\Lambda_c^+\to\Lambda\rho(770)^+)=&(4.06\pm0.30\pm0.35\pm0.23)\times10^{-2},\\ \mathcal{B}(\Lambda_c^+\to\Sigma(1385)^+\pi^0)=&(5.86\pm0.49\pm0.52\pm0.35)\times10^{-3},\\ \mathcal{B}(\Lambda_c^+\to\Sigma(1385)^0\pi^+)=&(6.47\pm0.59\pm0.66\pm0.38)\times10^{-3},\\ \end{aligned} \end{eqnarray*} where the first uncertainties are statistical, the second are systematic, and the third are from the uncertainties of the branching fractions $\mathcal{B}(\Lambda_c^+\to\Lambda\pi^+\pi^0)$ and $\mathcal{B}(\Sigma(1385)\to\Lambda\pi)$. In addition, %according to amplitudes determined from the partial wave analysis, the decay asymmetry parameters are measured to be $\alpha_{\Lambda\rho(770)^+}=-0.763\pm0.053\pm0.045$, $\alpha_{\Sigma(1385)^{+}\pi^0}=-0.917\pm0.069\pm0.056$, and $\alpha_{\Sigma(1385)^{0}\pi^+}=-0.789\pm0.098\pm0.056$.