Observation of ${\chi }_{cJ}\to \Lambda \bar{\Lambda }\eta$

Abstract

By analyzing $(448.1\pm 2.9)\times 10^6$ $\psi (3686)$ events collected with the BESIII detector operating at the BEPCII collider, the decays of ${\chi }_{cJ}\to \Lambda \bar{\Lambda }\eta$ ($J=0$, 1 and 2) are observed for the first time with statistical significances of $13.9\sigma$, $6.7\sigma$, and $8.2\sigma$, respectively. The product branching fractions of $\psi (3686)\to \gamma {\chi }_{cJ}$ and ${\chi }_{cJ}\to \Lambda \bar{\Lambda }\eta$ are measured. Dividing by the world averages of the branching fractions of $\psi (3686)\to \gamma {\chi }_{cJ}$, the branching fractions of ${\chi }_{cJ}\to \Lambda \bar{\Lambda }\eta$ decays are determined to be $(2.31\pm 0.30\pm 0.21)\times 10^{-4}$, $(5.86\pm 1.38\pm 0.68)\times 10^{-5}$, and $(1.05\pm 0.21\pm 0.15)\times 10^{-4}$ for $J=0$, 1 and 2, respectively, where the first uncertainties are statistical and the second systematic.

arXiv comment9 pages, 4 figures

References in corpus (9)

• Design and Construction of the BESIII Detector
• Coherent Exclusive Exponentiation For Precision Monte Carlo Calculations
• Search for hadronic transition ${\chi }_{cJ}\to {\eta }_c{\pi }^{+}{\pi }^{-}$ and observation of ${\chi }_{cJ}\to K\bar{K}\pi \pi \pi$
• TopoAna: A generic tool for the event type analysis of inclusive Monte-Carlo samples in high energy physics experiments
• Determination of the number of $\psi (3686)$ events at BESIII
• The meson-exchange model for the $\Lambda \bar{\Lambda }$ interaction
• Observation of B0 to Lambda Lambdabar K0 and B0 to Lambda Lambdabar K*0 at Belle
• Observation of a near-threshold enhancement in the $\Lambda \bar{\Lambda }$ mass spectrum from $e^{+}{e}^{-}\to \varphi \Lambda \bar{\Lambda }$ at $\sqrt{s}$ from 3.51 to 4.60 GeV
• Measurement of ${\chi }_{cJ}$ decaying into $p\bar{n}{\pi }^{-}$ and $p\bar{n}{\pi }^{-}{\pi }^0$

Cited by in corpus (2)

• Study of the decays ${\chi }_{cJ}\to \Lambda \bar{\Lambda }\varphi$
• First measurements of the branching fractions of $J/\psi \to {\Xi }^0\bar{\Lambda }{K}_S^0+c.c.$, $J/\psi \to {\Xi }^0{\bar{\Sigma }}^0{K}_S^0+c.c.$, and $J/\psi \to {\Xi }^0{\bar{\Sigma }}^{-}{K}^{+}+c.c.$