We report an experimental investigation of the reactions $\bar{n}p \to 2\pi^+\pi^-$, $\bar{n}p \to 2\pi^+\pi^-\pi^0$, and $\bar{n}p \to 2\pi^+\pi^-2\pi^0$ using $(10.087 \pm 0.044)\times10^{9}$ $J/\psi$ events collected with the BESIII detector at the BEPCII storage ring. The antineutron ($\bar{n}$) is produced in the decay $J/\psi \to p\pi^-\bar{n}$ with a studied momentum ranging from $200$ to $1174~\mathrm{MeV}/c$, while the target proton originates from the hydrogen nuclei in the cooling oil of the beam pipe. This novel method pioneers the study of $\bar{n}$-nucleon interactions at an $e^+e^-$ collider, providing the first experimental data for antineutron momenta exceeding $800~\mathrm{MeV}/c$.
Study of the Reactions 𝑛bar𝑝→2𝜋+𝜋−, 2𝜋+𝜋−𝜋0, and 2𝜋+𝜋−2𝜋0 Using 𝐽/𝜓→𝑝𝜋−𝑛bar
Garzia, I.;Melendi, F. M.;
2026
Abstract
We report an experimental investigation of the reactions $\bar{n}p \to 2\pi^+\pi^-$, $\bar{n}p \to 2\pi^+\pi^-\pi^0$, and $\bar{n}p \to 2\pi^+\pi^-2\pi^0$ using $(10.087 \pm 0.044)\times10^{9}$ $J/\psi$ events collected with the BESIII detector at the BEPCII storage ring. The antineutron ($\bar{n}$) is produced in the decay $J/\psi \to p\pi^-\bar{n}$ with a studied momentum ranging from $200$ to $1174~\mathrm{MeV}/c$, while the target proton originates from the hydrogen nuclei in the cooling oil of the beam pipe. This novel method pioneers the study of $\bar{n}$-nucleon interactions at an $e^+e^-$ collider, providing the first experimental data for antineutron momenta exceeding $800~\mathrm{MeV}/c$.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
