Measurements of charmonia decays from BESIII

Abstract

In this talk, recent measurements of charmonium decays of BESIII are presented. Using 448 million $\psi (3686)$ events collected with the BESIII detector, the branching fractions of the decays ${\chi }_{cJ}\to \varphi \varphi (J=0,1,2)$ have been measured most precisely, and the polarization parameters of ${\chi }_{cJ}\to \varphi \varphi$ have been determined for the first time via a helicity amplitude analysis. Using the same data sample as in the previous study, first evidence of ${\eta }_c(2S)\to {\pi }^{+}{\pi }^{-}\eta$ has been found in the decay sequence $\psi (3686)\to \gamma {\eta }_c(2S)(\to {\pi }^{+}{\pi }^{-}\eta )$. The product of the branching fractions of $\psi (3686)\to \gamma {\eta }_c(2S)$ and ${\eta }_c(2S)\to {\pi }^{+}{\pi }^{-}\eta$ is reported as well as the individual branching fraction of ${\eta }_c(2S)\to {\pi }^{+}{\pi }^{-}\eta$. The process $e^{+}{e}^{-}\to \eta J/\psi$ at a center-of-mass energy $3.773\mathrm{GeV}$ is observed for the first time. Its Born cross-section is measured, and the branching fraction of $\psi (3770)\to \eta J/\psi$ is determined by a combined fit with the cross sections at other energy points, after considering the interference effect for the first time. Utilizing 2708 million $\psi (3686)$ events collected by the BESIII detector, the decays ${\chi }_{cJ}\to {\Omega }^{-}{\bar{\Omega }}^{+}(J=0,1,2)$ have been observed for the first time with high significance via the radiative decays of $\psi (3686)\to \gamma {\chi }_{cJ}$. The relevant branching fractions have been provided.

Proceeding article for 21st Conference on Flavor Physics and CP Violation (FPCP 2023) 15 pages, 9 figures, 4tables

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• Heavy quarkonium: progress, puzzles, and opportunities
• Quarkonia and their transitions
• Effect of charmed meson loops on charmonium transitions
• Towards a dynamical understanding of the non-$D\bar{D}$ decay of $\psi (3770)$
• The evasion of helicity selection rule in ${\chi }_{c1}\to VV$ and ${\chi }_{c2}\to VP$ via intermediate charmed meson loops
• QCD prediction for the non-$D\bar{D}$ annihilation decay of $\psi (3770)$
• Open charm effects in $e^{+}{e}^{-}\to J/\psi \eta$, $J/\psi {\pi }^0$ and $\varphi {\eta }_c$
• Isospin violating decay of $\psi (3770)\to J/\psi +{\pi }^0$
• Detecting the polarization in ${\chi }_{cJ}\to \varphi \varphi$ decays to probe hadronic loop effect
• Evidence for ${\eta }_c$(2S)$\to\pipieta$ decay
• Observation of the decay ${\chi }_{cJ}\to {\Omega }^{-}{\bar{\Omega }}^{+}$

Cited by in corpus (1)

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