Study of the decays ${\chi }_{cJ}\to \Lambda \bar{\Lambda }\varphi$

Abstract

Based on $(2712.4\pm 14.3)\times 10^6$ $e^{+}{e}^{-}\to \psi (3686)$ events collected with the BESIII detector operating at the BEPCII collider, we report the first evidence of ${\chi }_{c0}\to \Lambda \bar{\Lambda }\varphi$ decays and the first observation of ${\chi }_{c1,2}\to \Lambda \bar{\Lambda }\varphi$ decays, with significances of $4.5\sigma$, $11.3\sigma$ and $13.0\sigma$, respectively. The decay branching fractions of ${\chi }_{c0,1,2}\to \Lambda \bar{\Lambda }\varphi$ are measured to be $(2.99\pm 1.24\pm 0.19)\times 10^{-5}$, $(6.01\pm 0.90\pm 0.40)\times 10^{-5}$, and $(7.13\pm 0.81\pm 0.36)\times 10^{-5}$, where the first uncertainties are statistical and the second systematic. No obvious enhancement near the $\Lambda \bar{\Lambda }$ production threshold or excited $\Lambda$ state is found in the $\Lambda \varphi$ (or $\bar{\Lambda }\varphi$) system.

arXiv comment10 pages, 9 figures

References in corpus (17)

• 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
• Observation of a near-threshold enhancement in th p pbar mass spectrum from radiative J/psi-->gamma p pbar decays
• Method for detector description transformation to Unity and application in BESIII
• Branching fraction measurements of χ_{c0} and χ_{c2} to π^0π^0 and ηη
• 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
• J/psi and psi(2S) Radiative Transitions to eta_c
• Spin-Parity Analysis of ppbar Mass Threshold Structure in J/psi and psi' Radiative Decays
• Determination of the number of $\psi (3686)$ events taken at BESIII
• The meson-exchange model for the $\Lambda \bar{\Lambda }$ interaction
• 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
• Measurements of psi'-> pbar K+ sigma0 and chi_cj->pbar K+ Lambda
• Measurement of $\psi (3686)\to \Lambda \bar{\Lambda }\eta$ and $\psi (3686)\to \Lambda \bar{\Lambda }{\pi }^0$ decays
• Observation of ${\chi }_{cJ}\to \Lambda \bar{\Lambda }\eta$
• Observation of the decays ${\chi }_{cJ}\to n{K}_S^0\bar{\Lambda }+c.c.$