Different mechanism of two-proton emission from proton-rich nuclei $^{23}$Al and $^{22}$Mg

Y. G. Ma; D. Q. Fang; X. Y. Sun; P. Zhou; Y. Togano; N. Aoi; H. Baba; X. Z. Cai; X. G. Cao; J. G. Chen; Y. Fu; W. Guo; Y. Hara; T. Honda; Z. G. Hu; K. Ieki; Y. Ishibashi; Y. Ito; N. Iwasa; S. Kanno; T. Kawabata; H. Kimura; Y. Kondo; K. Kurita; M. Kurokawa; T. Moriguchi; H. Murakami; H. Ooishi; K. Okada; S. Ota; A. Ozawa; H. Sakurai; S. Shimoura; R. Shioda; E. Takeshita; S. Takeuchi; W. D. Tian; H. W. Wang; J. S. Wang; M. Wang; K. Yamada; Y. Yamada; Y. Yasuda; K. Yoneda; G. Q. Zhang; T. Motobayashi

doi:10.1016/j.physletb.2015.02.066

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arXiv · 1503.05631

Different mechanism of two-proton emission from proton-rich nuclei $^{23}$Al and $^{22}$Mg

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Abstract

Two-proton relative momentum ($q_{pp}$) and opening angle ($θ_{pp}$) distributions from the three-body decay of two excited proton-rich nuclei, namely $^{23}$Al $\rightarrow$ p + p + $^{21}$Na and $^{22}$Mg $\rightarrow$ p + p + $^{20}$Ne, have been measured with the projectile fragment separator (RIPS) at the RIKEN RI Beam Factory. An evident peak at $q_{pp}\sim20$ MeV/c as well as a peak in $θ_{pp}$ around 30$^\circ$ are seen in the two-proton break-up channel from a highly-excited $^{22}$Mg. In contrast, such peaks are absent for the $^{23}$Al case. It is concluded that the two-proton emission mechanism of excited $^{22}$Mg is quite different from the $^{23}$Al case, with the former having a favorable diproton emission component at a highly excited state and the latter dominated by the sequential decay process.

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Y. G. Ma, D. Q. Fang, X. Y. Sun, P. Zhou, Y. Togano, N. Aoi, H. Baba, X. Z. Cai, X. G. Cao, J. G. Chen, Y. Fu, W. Guo, Y. Hara, T. Honda, Z. G. Hu, K. Ieki, Y. Ishibashi, Y. Ito, N. Iwasa, S. Kanno, T. Kawabata, H. Kimura, Y. Kondo, K. Kurita, M. Kurokawa, T. Moriguchi, H. Murakami, H. Ooishi, K. Okada, S. Ota, A. Ozawa, H. Sakurai, S. Shimoura, R. Shioda, E. Takeshita, S. Takeuchi, W. D. Tian, H. W. Wang, J. S. Wang, M. Wang, K. Yamada, Y. Yamada, Y. Yasuda, K. Yoneda, G. Q. Zhang, T. Motobayashi. 2015-03-19. Different mechanism of two-proton emission from proton-rich nuclei $^{23}$Al and $^{22}$Mg. https://doi.org/10.1016/j.physletb.2015.02.066

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