Charge-changing cross sections for <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi>Ca</mml:mi><mml:mprescripts/><mml:none/><mml:mrow><mml:mn>42</mml:mn><mml:mtext>–</mml:mtext><mml:mn>51</mml:mn></mml:mrow></mml:mmultiscripts></mml:math> and effect of charged-particle evaporation induced by neutron-removal reactions
M. Tanaka, M. Takechi, A. Homma, A. Prochazka, M. Fukuda, D. Nishimura, Toshio Suzuki, T. Moriguchi, D. S. Ahn, A. Aimaganbetov, M. Amano, Hiroshi Arakawa, S. Bagchi, K.-H. Behr, N. Burtebayev, K. Chikaato, Hang Du, Tomoya Fujii, N. Fukuda, H. Geißel, T. Hori, S. Hoshino, R. Igosawa, A. Ikeda, N. Inabe, K. Inomata, K. Itahashi, T. Izumikawa, D. Kamioka, N. Kanda, Ikuma Kato, Inesh Kenzhina, Z. Korkulu, Y. Kuk, K. Kusaka, K. Matsuta, M. Mihara, E. Miyata, D. Nagae, Satoshi Nakamura, M. Nassurlla, K. Nishimuro, K. Nishizuka, Kazuhiro Ohnishi, M. Ohtake, T. Ohtsubo, Shunichiro Omika, H. J. Ong, A. Ozawa, H. Sakuraï, C. Scheidenberger, Y. Shimizu, T. Sugihara, T. Sumikama, Hiroaki Suzuki, S. Suzuki, H. Takeda, Y. Tanaka, Y. Tanaka, I. Tanihata, Takehiko Wada, Kiyoshi Wakayama, S. Yagi, Takayuki Yamaguchi, R. Yanagihara, Y. Yanagisawa, K. Yoshida, T.K. Zholdybayev
Abstract
Charge-changing cross sections ${\ensuremath{\sigma}}_{\mathrm{CC}}$ for $^{42\text{--}51}\mathrm{Ca}$ on a carbon target at around 280 MeV/nucleon have been measured. Though the existing point-proton radii ${r}_{\mathrm{p}}$ of Ca isotopes increase as the neutron number increases, the measured ${\ensuremath{\sigma}}_{\mathrm{CC}}$ data show a significant decrease, which is against the expectation from a simple Glauber-like model. We found that this observed phenomenon could be attributed to the charged-particle evaporation effect induced by the neutron-removal reaction. By taking the evaporation effect into account, various ${\ensuremath{\sigma}}_{\mathrm{CC}}$ data sets for nuclides from C to Fe isotopes on $^{12}\mathrm{C}$ measured at around 280 MeV/nucleon are reproduced with a standard deviation of 1.6%. It is also clarified that this evaporation effect becomes negligibly small in the neutron-rich region. The evaluated relation between ${\ensuremath{\sigma}}_{\mathrm{CC}}$ and ${r}_{\mathrm{p}}$ using the current model indicates that ${\ensuremath{\sigma}}_{\mathrm{CC}}$ data for neutron-rich Ca isotopes ($A\ensuremath{\ge}51$) are highly sensitive to ${r}_{\mathrm{p}}$. This high sensitivity potentially allows one to determine the ${r}_{\mathrm{p}}$ of very neutron-rich nuclei.