Observation of a $\bar{K}NN$ bound state in the $^3{\rm He} (K^-, ��p)n$ reaction
| Autor: | Yamaga, T., Ajimura, S., Asano, H., Beer, G., Bhang, H., Bragadireanu, M., Buehler, P., Busso, L., Cargnelli, M., Choi, S., Curceanu, C., Enomoto, S., Fujioka, H., Fujiwara, Y., Fukuda, T., Guaraldo, C., Hashimoto, T., Hayano, R. S., Hiraiwa, T., Iio, M., Iliescu, M., Inoue, K., Ishiguro, Y., Ishikawa, T., Ishimoto, S., Itahashi, K., Iwai, M., Iwasaki, M., Kanno, K., Kato, K., Kato, Y., Kawasaki, S., Kienle, P., Kou, H., Ma, Y., Marton, J., Matsuda, Y., Mizoi, Y., Morra, O., Nagae, T., Noumi, H., Ohnishi, H., Okada, S., Outa, H., Piscicchia, K., Sada, Y., Sakaguchi, A., Sakuma, F., Sato, M., Scordo, A., Sekimoto, M., Shi, H., Shirotori, K., Sirghi, D., Sirghi, F., Suzuki, S., Suzuki, T., Tanida, K., Tatsuno, H., Tokuda, M., Tomono, D., Toyoda, A., Tsukada, K., Doce, O. Vazquez, Widmann, E., Yamazaki, T., Yim, H., Zhang, Q., Zmeskal, J. |
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| Rok vydání: | 2020 |
| Předmět: | |
| DOI: | 10.48550/arxiv.2006.13433 |
| Popis: | We have performed an exclusive measurement of the $K^{-}+\! ~^{3}{\rm He} \to ��pn$ reaction at an incident kaon momentum of $1\ {\rm GeV}/c$.In the $��p$ invariant mass spectrum, a clear peak was observed below the mass threshold of $\bar{K}\!+\!N\!+\!N$, as a signal of the kaonic nuclear bound state, $\bar{K}NN$.The binding energy, decay width, and $S$-wave Gaussian reaction form-factor of this state were observed to be $B_{K} = 42\pm3({\rm stat.})^{+3}_{-4}({\rm syst.})\ {\rm MeV}$, $��_{K} = 100\pm7({\rm stat.})^{+19}_{-9}({\rm syst.})\ {\rm MeV}$, and $Q_{K} = 383\pm11({\rm stat.})^{+4}_{-1}({\rm syst.})\ {\rm MeV}/c$, respectively. The total production cross-section of $\bar{K}NN$, determined by its $��p$ decay mode, was $��^{tot}_{K} \cdot BR_{��p} = 9.3\pm0.8({\rm stat.})^{+1.4}_{-1.0}({\rm syst.})\ ��{\rm b}$.We estimated the branching ratio of the $\bar{K}NN$ state to the $��p$ and $��^{0}p$ decay modes as $BR_{��p}/BR_{��^{0}p} \sim 1.7$, by assuming that the physical processes leading to the $��N\!N$ final states are analogous to those of $��pn$. 13 pages, 12 figures |
| Databáze: | OpenAIRE |
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