Extended neutron orbital and the shell closure in Ca

Caにおける広がった中性子軌道と閉殻

Enciu, M.*; Liu, H. N.*; Obertelli, A.*; Doornenbal, P.*; Nowacki, F.*; 緒方 一介*; Poves, A.*; 吉田 数貴   ; Achouri, N. L.*; 馬場 秀忠*; Browne, F.*; Calvet, D.*; Chteau, F.*; Chen, S.*; 千賀 信幸*; Corsi, A.*; Corts, M. L.*; Delbart, A.*; Gheller, J.-M.*; Giganon, A.*; Gillibert, A.*; Hilaire, C.*; 磯部 忠昭*; 小林 俊雄*; 久保田 悠樹*; Lapoux, V.*; 本林 透*; Murray, I.*; 大津 秀暁*; Panin, V.*; Paul, N.*; Rodriguez, W.*; 櫻井 博儀*; 笹野 匡紀*; Steppenbeck, D.*; Stuhl, L.*; Sun, Y. L.*; 栂野 泰宏*; 上坂 友洋*; Wimmer, K.*; 米田 健一郎*; Aktas, O.*; Aumann, T.*; Chung, L. X.*; Flavigny, F.*; Franchoo, S.*; Gasparic, I.*; Gerst, R.-B.*; Gibelin, J.*; Hahn, K. I.*; Kim, D.*; 近藤 洋介*; Koseoglou, P.*; Lee, J.*; Lehr, C.*; Li, P. J.*; Linh, B. D.*; Lokotko, T.*; MacCormick, M.*; Moschner, K.*; 中村 隆司*; Park, S. Y.*; Rossi, D.*; Sahin, E.*; Sderstrm, P.-A.*; Sohler, D.*; 武内 聡*; Toernqvist, H.*; Vaquero, V.*; Wagner, V.*; Wang, S.*; Werner, V.*; Xu, X.*; 山田 啓貴*; Yan, D.*; Yang, Z.*; 安田 昌弘*; Zanetti, L.*

Enciu, M.*; Liu, H. N.*; Obertelli, A.*; Doornenbal, P.*; Nowacki, F.*; Ogata, Kazuyuki*; Poves, A.*; Yoshida, Kazuki; Achouri, N. L.*; Baba, Hidetada*; Browne, F.*; Calvet, D.*; Chteau, F.*; Chen, S.*; Chiga, Nobuyuki*; Corsi, A.*; Corts, M. L.*; Delbart, A.*; Gheller, J.-M.*; Giganon, A.*; Gillibert, A.*; Hilaire, C.*; Isobe, Tadaaki*; Kobayashi, Toshio*; Kubota, Yuki*; Lapoux, V.*; Motobayashi, Toru*; Murray, I.*; Otsu, Hideaki*; Panin, V.*; Paul, N.*; Rodriguez, W.*; Sakurai, Hiroyoshi*; Sasano, Masaki*; Steppenbeck, D.*; Stuhl, L.*; Sun, Y. L.*; Togano, Yasuhiro*; Uesaka, Tomohiro*; Wimmer, K.*; Yoneda, Kenichiro*; Aktas, O.*; Aumann, T.*; Chung, L. X.*; Flavigny, F.*; Franchoo, S.*; Gasparic, I.*; Gerst, R.-B.*; Gibelin, J.*; Hahn, K. I.*; Kim, D.*; Kondo, Yosuke*; Koseoglou, P.*; Lee, J.*; Lehr, C.*; Li, P. J.*; Linh, B. D.*; Lokotko, T.*; MacCormick, M.*; Moschner, K.*; Nakamura, Takashi*; Park, S. Y.*; Rossi, D.*; Sahin, E.*; Sderstrm, P.-A.*; Sohler, D.*; Takeuchi, Satoshi*; Toernqvist, H.*; Vaquero, V.*; Wagner, V.*; Wang, S.*; Werner, V.*; Xu, X.*; Yamada, Hiroki*; Yan, D.*; Yang, Z.*; Yasuda, Masahiro*; Zanetti, L.*

230MeV/nucleonでのCaからの中性子ノックアウト反応が線分光と行われ、と軌道からの中性子ノックアウト反応の運動量分布が測定された。断面積はの閉殻と整合し、Ca同位体でのと閉殻と同程度に強い閉殻であることが確認された。運動量分布の分析からと軌道の平均二乗根半径の差は0.61(23)fmと決定され、これはmodified-shell-modelによる予言の0.7fmと整合した。これは、中性子過剰なCa同位体での軌道半径が大きいことが、中性子数にしたがって線形的に荷電半径が増える意外な現象の原因であることを示唆している。

The one-neutron knockout from Ca was performed at 230 MeV/nucleon combined with prompt spectroscopy. The momentum distributions corresponding to the removal of and neutrons were measured. The cross sections are consistent with a shell closure at the neutron number , found as strong as at and in Ca isotopes from the same observables. The analysis of the momentum distributions leads to a difference of the root-mean-square radii of the neutron and orbitals of 0.61(23) fm, in agreement with the modified-shell-model prediction of 0.7 fm suggesting that the large root-mean-square radius of the orbital in neutron-rich Ca isotopes is responsible for the unexpected linear increase of the charge radius with the neutron number.