First Study of Reaction Ξ0n→Ξ−p Using Ξ0 -Nucleus Scattering at an Electron-Positron Collider

Le résumé fourni par la source

Using $(1.0087\ifmmode\pm\else\textpm\fi{}0.0044)\ifmmode\times\else\texttimes\fi{}{10}^{10}\text{ }\text{ }J/\ensuremath{\psi}$ events collected with the BESIII detector at the BEPCII storage ring, the process ${\mathrm{\ensuremath{\Xi}}}^{0}n\ensuremath{\rightarrow}{\mathrm{\ensuremath{\Xi}}}^{\ensuremath{-}}p$ is studied, where the ${\mathrm{\ensuremath{\Xi}}}^{0}$ baryon is produced in the process $J/\ensuremath{\psi}\ensuremath{\rightarrow}{\mathrm{\ensuremath{\Xi}}}^{0}{\overline{\mathrm{\ensuremath{\Xi}}}}^{0}$ and the neutron is a component of the $^{9}\mathrm{Be}$, $^{12}\mathrm{C}$, and $^{197}\mathrm{Au}$ nuclei in the beam pipe. A clear signal is observed with a statistical significance of $7.1\ensuremath{\sigma}$. The cross section of the reaction ${\mathrm{\ensuremath{\Xi}}}^{0}+^{9}\mathrm{Be}\ensuremath{\rightarrow}{\mathrm{\ensuremath{\Xi}}}^{\ensuremath{-}}+p+^{8}\mathrm{Be}$ is determined to be $\ensuremath{\sigma}({\mathrm{\ensuremath{\Xi}}}^{0}+^{9}\mathrm{Be}\ensuremath{\rightarrow}{\mathrm{\ensuremath{\Xi}}}^{\ensuremath{-}}+p+^{8}\mathrm{Be})=(22.1\ifmmode\pm\else\textpm\fi{}{5.3}_{\mathrm{stat}}\ifmmode\pm\else\textpm\fi{}{4.5}_{\mathrm{sys}})\text{ }\text{ }\mathrm{mb}$ at the ${\mathrm{\ensuremath{\Xi}}}^{0}$ momentum of $0.818\text{ }\text{ }\mathrm{GeV}/c$, where the first uncertainty is statistical and the second is systematic. No significant $H$-dibaryon signal is observed in the ${\mathrm{\ensuremath{\Xi}}}^{\ensuremath{-}}p$ final state. This is the first study of hyperon-nucleon interactions in electron-positron collisions and opens up a new direction for such research.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.