Matter radius of the doubly-magic $$^{56}$$Ni measured in a storage ring

• Published in: The European physical journal. A, Hadrons and nuclei Hadrons and nuclei, 2023-04, Vol.59 (4), Article 83
• Main Authors: von Schmid, M., Aumann, T., Bagchi, S., Bönig, S., Csatlós, M., Dillmann, I., Dimopoulou, C., Egelhof, P., Eremin, V., Furuno, T., Geissel, H., Gernhäuser, R., Harakeh, M. N., Hartig, A.-L., Ilieva, S., Kalantar-Nayestanaki, N., Kiselev, O., Kollmus, H., Kozhuharov, C., Krasznahorkay, A., Kröll, Th, Kuilman, M., Litvinov, S., Litvinov, Yu. A., Mahjour-Shafiei, M., Mutterer, M., Nagae, D., Najafi, M. A., Nociforo, C., Nolden, F., Popp, U., Rigollet, C., Roth, R., Roy, S., Scheidenberger, C., Steck, M., Streicher, B., Stuhl, L., Thürauf, M., Uesaka, T., Weick, H., Winfield, J. S., Winters, D., Woods, P. J., Yamaguchi, T., Yue, K., Zamora Cardona, J. C., Zenihiro, J.
• Format: Article
• Language: English
• ISSN: 1434-601X; 1434-601X
• DOI: 10.1140/epja/s10050-023-00967-z

The matter radius of the doubly magic $$^{56}$$ 56 Ni was extracted from a measurement of the differential cross section by employing, for the first time, elastic proton scattering in inverse kinematics with a radioactive beam at $$E_{kin}=390.2$$ E kin = 390.2  MeV/nucleon circulating in a storage ring and passing an internal hydrogen gas-jet target with a revolution frequency of around 2 MHz. The novel experimental scheme is based on UHV-compatible Si detectors operated as active vacuum windows, which were implemented in the ESR storage ring at GSI. A matter radius $$^{1/2}=3.74^{+0.03}_{-0.06}$$ < r m 2 > 1 / 2 = 3 . 74 - 0.06 + 0.03  fm was extracted for the doubly-magic self-conjugate nucleus $$^{56}$$ 56 Ni.