Observation of a New $X(3872)$ Production Process $e^+e^-\toÏX(3872)$
arXiv:2212.07291 · doi:10.1103/PhysRevLett.130.151904
Abstract
Using $4.7~\rm fb^{-1}$ of $e^+e^-$ collision data at center-of-mass energies from 4.661 to 4.951 GeV collected by the BESIII detector at the BEPCII collider, we observe the $X(3872)$ production process $e^{+}e^{-}\toÏX(3872)$ for the first time. The significance is $7.8Ï$, including both the statistical and systematic uncertainties. The $e^+e^-\toÏX(3872)$ Born cross section and the corresponding upper limit at 90\% confidence level at each energy point are reported. The line shape of the cross section indicates that the $ÏX(3872)$ signals may be from the decays of some non-trivial structures.
8 pages, 3 figures