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تسجيل مستخدم جديدCross section measurement of $e^+e^- rightarrow etaJ/psi$ from $sqrt{s} = 4.178$ to $4.600$ GeV
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The cross section of the process $e^+e^- rightarrow etaJ/psi$ is measured at center-of-mass energies from $sqrt{s} =$ 4.178 to 4.600 GeV using data samples corresponding to a total integrated luminosity of 11 fb$^{-1}$ collected with the BESIII detector operating at the BEPCII storage ring. The dependence of the cross section on $sqrt{s}$ shows an enhancement around $4.2$ GeV. While the shape of the cross section cannot be fully explained with a single $psi(4160)$ or $psi(4260)$ state, a coherent sum of the two states does provide a reasonable description of the data.
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Using data samples with a total integrated luminosity of $20.1~rm fb^{-1}$ collected by the BESIII detector operating at the BEPCII collider, the cross section of the process $e^+e^- rightarrow pi^+pi^-psi(3686)$ is measured at center-of-mass energie
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The dependence of the cross section on $sqrt{s}$ shows a resonant structure with mass of $(4218.5pm1.6(text{stat.})pm4.0(text{syst.}))$ MeV/$c^2$ and width of $(28.2pm3.9(text{stat.})pm1.6(text{syst.}))$ MeV, respectively. This observation confirms and improves upon the result of a previous study. The angular distribution of the $e^+e^- rightarrow omega chi_{c0}$ process is extracted for the first time.
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