Observation of $Ξ(1620)^0$ and evidence for $Ξ(1690)^0$ in $Ξ_c^+ \rightarrow Ξ^-π^+π^+$ decays
Creators: name: Belle Collaboration
name: Sumihama, M.
name: Adachi, I.
name: Ahn, J. K.
name: Aihara, H.
name: Said, S. Al
name: Asner, D. M.
name: Atmacan, H.
name: Aushev, T.
name: Ayad, R.
name: Babu, V.
name: Badhrees, I.
name: Bahinipati, S.
name: Bakich, A. M.
name: Bansal, V.
name: Beleno, C.
name: Berger, M.
name: Bhardwaj, V.
name: Bhuyan, B.
name: Bilka, T.
name: Biswal, J.
name: Bonvicini, G.
name: Bozek, A.
name: Bracko, M.
name: Browder, T. E.
name: Cervenkov, D.
name: Chekelian, V.
name: Chen, A.
name: Cheon, B. G.
name: Chilikin, K.
name: Cho, K.
name: Choi, S. -K.
name: Choi, Y.
name: Choudhury, S.
name: Cinabro, D.
name: Czank, S. Cunliffe
name: Dash, N.
name: Di Carlo, S.
name: Dolezal, Z.
name: Dong, T. V.
name: Drasal, Z.
name: Eidelman, S.
name: Epifanov, D.
name: Fast, J. E.
name: Fulsom, B. G.
name: Garg, R.
name: Gaur, V.
name: Gabyshev, N.
name: Garmash, A.
name: Gelb, M.
name: Giri, A.
name: Goldenzweig, P.
name: Guido, E.
name: Haba, J.
name: Hayasaka, K.
name: Hayashii, H.
name: Hirose, S.
name: Hou, W. -S.
name: Inami, K.
name: Inguglia, G.
name: Ishikawa, A.
name: Itoh, R.
name: Iwasaki, M.
name: Iwasaki, Y.
name: Jacobs, W. W.
name: Jeon, H. B.
name: Jia, S.
name: Jin, Y.
name: Joo, K. K.
name: Julius, T.
name: Kaliyar, A. B.
name: Kang, K. H.
name: Karyan, G.
name: Kato, Y.
name: Kiesling, C.
name: Kim, D. Y.
name: Kim, J. B.
name: Kim, K. T.
name: Kim, S. H.
name: Kinoshita, K.
name: Kodys, P.
name: Korpar, S.
name: Kotchetkov, D.
name: Krizan, P.
name: Kroeger, R.
name: Krokovny, P.
name: Kumar, R.
name: Kuzmin, A.
name: Kwon, Y. -J.
name: Lange, J. S.
name: Lee, I. S.
name: Lee, S. C.
name: Li, L. K.
name: Li, Y. B.
name: Gioi, L. Li
name: Libby, J.
name: Liventsev, D.
name: Lubej, M.
name: Luo, T.
name: Masuda, M.
name: Matsuda, T.
name: Matvienko, D.
name: Merola, M.
name: Miyabayashi, K.
name: Miyata, H.
name: Mizuk, R.
name: Mohanty, G. B.
name: Moon, H. K.
name: Mori, T.
name: Mussa, R.
name: Nakano, E.
name: Nakano, T.
name: Nakao, M.
name: Nanut, T.
name: Nath, K. J.
name: Natkaniec, Z.
name: Niiyama, M.
name: Nisar, N. K.
name: Nishida, S.
name: Ono, H.
name: Pakhlov, P.
name: Pakhlova, G.
name: Pal, B.
name: Pardi, S.
name: Park, H.
name: Paul, S.
name: Pedlar, T. K.
name: Pestotnik, R.
name: Piilonen, L. E.
name: Popov, V.
name: Ritter, M.
name: Russo, G.
name: Sahoo, D.
name: Sandilya, S.
name: Santelj, L.
name: Sanuki, T.
name: Savinov, V.
name: Schneider, O.
name: Schnell, G.
name: Schwanda, C.
name: Seino, Y.
name: Senyo, K.
name: Sevior, M. E.
name: Shebalin, V.
name: Shen, C. P.
name: Shibata, T. -A.
name: Shiu, J. -G.
name: Shwartz, B.
name: Simon, F.
name: Sokolov, A.
name: Solovieva, E.
name: Staric, M.
name: Strube, J. F.
name: Sumiyoshi, T.
name: Takizawa, M.
name: Tamponi, U.
name: Tanida, K.
name: Taniguchi, N.
name: Tenchini, F.
name: Uchida, M.
name: Uglov, T.
name: Uno, S.
name: Urquijo, P.
name: Vahsen, S. E.
name: Van Hulse, C.
name: Varner, G.
name: Vorobyev, V.
name: Vossen, A.
name: Wang, B.
name: Wang, C. H.
name: Wang, M. -Z.
name: Wang, P.
name: Wang, X. L.
name: Watanabe, M.
name: Watanuki, S.
name: Widmann, E.
name: Won, E.
name: Ye, H.
name: Yelton, J.
name: Yuan, C. Z.
name: Yusa, Y.
name: Zakharov, S.
name: Zhang, Z. P.
name: Zhilich, V.
name: Zhukova, V.
name: Zhulanov, V.
Publisher: name: arXiv
Year: 2018
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: We report the first observation of the doubly-strange baryon $Ξ(1620)^0$ in its decay to $Ξ^-π^+$ via $Ξ_c^+ \rightarrow Ξ^- π^+ π^+$ decays based on a $980\,{\rm fb}^{-1}$ data sample collected with the Belle detector at the KEKB asymmetric-energy $e^+ e^-$ collider. The mass and width are measured to be 1610.4 $\pm$ 6.0 (stat) $^{+5.9}_{-3.5}$ (syst)~MeV$/c^2$ and 59.9 $\pm$ 4.8 (stat) $^{+2.8}_{-3.0}$ (syst)~MeV, respectively. We obtain 4.0$σ$ evidence of the $Ξ(1690)^0$ with the same data sample. These results shed light on the structure of hyperon resonances with strangeness $S=-2$.
description: 6 pages, 3 figures, To be submitted to Phys. Rev. Lett