Measurement of $\psi (3686)\to \Lambda \bar{\Lambda }\eta$ and $\psi (3686)\to \Lambda \bar{\Lambda }{\pi }^0$ decays

Abstract

Based on a sample of $448.1\times 10^6\psi (3686)$ events collected with the BESIII detector, a study of $\psi (3686)\to \Lambda \bar{\Lambda }{\pi }^0$ and $\psi (3686)\to \Lambda \bar{\Lambda }\eta$ is performed. Evidence of the isospin-violating decay $\psi (3686)\to \Lambda \bar{\Lambda }{\pi }^0$ is found for the first time with a statistical significance of $3.7\sigma$, the branching fraction $\mathcal{B}(\psi (3686)\to \Lambda \bar{\Lambda }{\pi }^0)$ is measured to be $(1.42\pm 0.39\pm 0.59)\times 10^{-6}$, and its corresponding upper limit is determined to be $2.47\times 10^{-6}$ at 90\% confidence level. A partial wave analysis of $\psi (3686)\to \Lambda \bar{\Lambda }\eta$ shows that the peak around $\Lambda \eta$ invariant mass threshold favors a ${\Lambda }^{\ast }$ resonance with mass and width in agreement with the $\Lambda (1670)$. The branching fraction of the $\psi (3686)\to \Lambda \bar{\Lambda }\eta$ is measured to be $(2.34\pm 0.18\pm 0.52)\times 10^{-5}$. The first uncertainties are statistical and the second are systematic.

arXiv comment11 pages, 7 figures, consistent with paper published in Phys. Rev. D 106, 072006 (2022)

References in corpus (15)

• Design and Construction of the BESIII Detector
• The Precision Monte Carlo Event Generator KK For Two-Fermion Final States In e+e- Collisions
• Coherent Exclusive Exponentiation For Precision Monte Carlo Calculations
• Future Physics Programme of BESIII
• Gauge Invariant Lagrangians for Free and Interacting Higher Spin Fields. A Review of the BRST formulation
• Search for hadronic transition ${\chi }_{cJ}\to {\eta }_c{\pi }^{+}{\pi }^{-}$ and observation of ${\chi }_{cJ}\to K\bar{K}\pi \pi \pi$
• Study of ${\chi }_{cJ}$ radiative decays into a vector meson
• TopoAna: A generic tool for the event type analysis of inclusive Monte-Carlo samples in high energy physics experiments
• Progress in FDC Project
• Determination of the number of $\psi (3686)$ events at BESIII
• Cross section measurements of $e^{+}{e}^{-}\to \omega {\chi }_{c0}$ from $\sqrt{s}=$4.178 to 4.278 GeV
• Study of $J/\psi$ and $\psi (3686)$ decay to $\Lambda \bar{\Lambda }$ and ${\Sigma }^0{\bar{\Sigma }}^0$ final states
• Combined estimation for multi-measurements of branching ratio
• Search for the ${\eta }_c(2S)/h_c\to p\bar{p}$ decays and measurements of the ${\chi }_{cJ}\to p\bar{p}$ branching fractions
• Impact of the interference between the resonance and continuum amplitudes on vector quarkonia decay branching fraction measurements

Cited by in corpus (6)

• Measurement of $e^{+}{e}^{-}\to \Lambda \bar{\Lambda }\eta$ from 3.5106 to 4.6988 GeV and study of $\Lambda \bar{\Lambda }$ mass threshold enhancement
• Observation of the $\psi (3686)$ decays into ${\Sigma }^{+}{\bar{\Sigma }}^{-}\omega$ and ${\Sigma }^{+}{\bar{\Sigma }}^{-}\varphi$
• Study of the decay ψ(3686) \to Σ^{0}\barΣ^{0}ϕ
• Study of the decays ${\chi }_{cJ}\to \Lambda \bar{\Lambda }\varphi$
• Observation of the decay $\psi (3686)\to {\Sigma }^0{\bar{\Sigma }}^0\omega$
• Monte Carlo Simulation-Based Partial Wave Analysis of ${\Xi }_c^{+}\to {\Xi }^{-}{\pi }^{+}{\pi }^{+}$ Decay