Production of the “K⁻pp”-like structure in the d(π⁺,K⁺) reaction at 1.69 GeV/c

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• 作者：Tomofumi Nagae ^{nagae@scphys.kyoto-u.ac.jp" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Kaonic Nuclei ; Λ(1405)Λ(1405) ; K¯ ; N interaction
• 刊名：Nuclear Physics A
• 出版年：2016
• 出版时间：October 2016
• 年：2016
• 卷：954
• 期：Complete
• 页码：94-113
• 全文大小：1222 K

文摘

We have investigated the π⁺+d→K⁺+X${\pi }^{+}+d\to K^{+}+X$ reaction at 1.69 GeV/c   at the hadron experimental hall of J-PARC. Systems with baryon number B=2$B=2$ and strangeness S=−1$S=-1$ are produced in this reaction. Owing to the very wide momentum acceptance of the spectrometer, we were able to search from the ΛN   threshold to above the $\overline{K}NN$ threshold, which covers the energy region where the K⁻pp$K^{-}pp$ bound state and/or the Σ(1385)N$\mathrm{\Sigma }(1385)N$ bound state could show up.

We observed a significant shift of the quasi-free Σ(1385)/Λ(1405)$\mathrm{\Sigma }(1385)/\mathrm{\Lambda }(1405)$ production peak by approximately 30 MeV to the lighter mass side. Further, with the coincidence of two protons in the final state, a broad bump structure was observed with a mass and width of ${2275}_{-18}^{+17}{\text{(stat.)}}_{-30}^{+21}\text{(syst.)}\text{MeV}/c^2$ and ${162}_{-45}^{+87}{\text{(stat.)}}_{-78}^{+66}\text{(syst.)}\text{MeV}$ coming from the K⁻pp→Σ⁰+p$K^{-}pp\to {\mathrm{\Sigma }}^0+p$ decay.