First spectroscopic study of Ar by the (,2) reaction

Juhsz, M. M.*; Elekes, Z.*; Sohler, D.*; Utsuno, Yutaka   ; Yoshida, Kazuki   ; Otsuka, Takaharu*; Ogata, Kazuyuki*; Doornenbal, P.*; Obertelli, A.*; 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, T.*; 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*; Achouri, N. L.*; Aktas, O.*; Aumann, T.*; Chung, L. X.*; Dombrdi, Zs.*; Flavigny, F.*; Franchoo, S.*; Gapari, I.*; Gerst, R.-B.*; Gibelin, J.*; Hahn, K. I.*; Kim, D.*; Koiwai, Takuma*; Kondo, Yosuke*; Koseoglou, P.*; Lee, J.*; Lehr, C.*; Linh, B. D.*; Liu, H. N.*; Lokotko, T.*; MacCormick, M.*; Moschner, K.*; Nakamura, Takashi*; Park, S. Y.*; Rossi, D.*; Sahin, E.*; Sderstrm, P.-A.*; Takeuchi, Satoshi*; Trnqvist, H.*; Vaquero, V.*; Wagner, V.*; Wang, S.*; Werner, V.*; Xu, X.*; Yamada, Hiroki*; Yan, D.*; Yang, Z.*; Yasuda, Masahiro*; Zanetti, L.*

The nuclear structure of Ar was studied by the (,2) reaction using -ray spectroscopy for the bound and unbound states. Comparing the results to our shell-model calculations, two bound and six unbound states were established. The low cross sections populating the two bound states of Ar could be interpreted as a clear signature for the presence of significant sub-shell closures at neutron numbers 32 and 34 in argon isotopes.