Precise measurement of the $e^{+}e^{-}\rightarrow D_{s}^{\ast+}D_{s}^{\ast-}$ cross sections at center-of-mass energies from threshold to 4.95 GeV

TL;DR

This paper reports the first high-precision measurements of the cross sections for the process $e^{+}e^{-} o D_{s}^{*+} D_{s}^{* -}$ from threshold to 4.95 GeV, revealing multiple resonance structures and their properties.

Contribution

It provides the first precise measurements of the cross sections and identifies multiple resonance structures in the energy region, including their masses and widths.

Findings

Two resonance structures observed at 4.1865 and 4.4145 GeV.

Measured resonance widths of 55 and 122.6 MeV.

Evidence for a third structure around 4.79 GeV.

Abstract

The process $e^{+}e^{-}\rightarrow D_{s}^{\ast+}D_{s}^{\ast-}$ is studied with a semi-inclusive method using data samples at center-of-mass energies from threshold to 4.95 GeV collected with the BESIII detector operating at the Beijing Electron Positron Collider. The Born cross sections of the process are measured for the first time with high precision in this energy region. Two resonance structures are observed in the energy-dependent cross sections around 4.2 and 4.4 GeV. By fitting the cross sections with a coherent sum of three Breit-Wigner amplitudes and one phase-space amplitude, the two significant structures are assigned masses of (4186.5$\pm$9.0$\pm$30) MeV/$c^{2}$ and (4414.5$\pm$3.2$\pm$6.0) MeV/$c^{2}$, widths of (55$\pm$17$\pm$53) MeV and (122.6$\pm$7.0$\pm$8.2) MeV, where the first errors are statistical and the second ones are systematic. The inclusion of a third Breit-Wigner amplitude is necessary to describe a structure around 4.79 GeV.