Description
In this presentation, we'll discuss the recent measurements of the
cross-sections for e⁺e⁻ annihilation into hidden charm states at BESIII. These
measurements include: 1) A precise measurement of the e⁺e⁻ → π⁺π⁻ $h_c$cross section
line shape at center-of-mass energies from 4.009 to 4.950 GeV. A plateau-like shape
between 4.3 and 4.45 GeV, followed by a sharp drop near 4.5 GeV, reveals three
resonant structures for the first time. 2) A search for the process $e⁺e⁻ → K_s K_s
h_c$ is conducted at 13 center-of-mass energies ranging from 4.600 to 4.950 GeV. No
significant signal is observed, and the upper limits of the Born cross-sections at
each center-of-mass energy are presented; 3) The observation of the process $e⁺e⁻ →
K_s K_s ψ(3686)$ at eight center-of-mass energies from 4.682 to 4.951 GeV, with an
integrated luminosity of 4.1 fb⁻¹. This process is reported for the first time with
a statistical significance of 6.3σ, and the cross-sections at each center-of-mass
energy are measured; 4) The inclusive cross-sections for prompt J/ψ and ψ(3686)
production at center-of-mass energies ranging from 3.808 to 4.951 GeV, based on 22
fb⁻¹ of annihilation data. Average cross-section values for J/ψ and ψ(3686) are
determined within specific energy ranges.
| Secondary track | T07 - Flavour Physics and CP Violation |
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