Search for $\alpha$ condensed states in $^{13}$C using $\alpha$ inelastic scattering
| Autor: | Inaba, K., Sasamoto, Y., Kawabata, T., Fujiwara, M., Funaki, Y., Hatanaka, K., Itoh, K., Itoh, M., Kawase, K., Matsubara, H., Maeda, Y., Suda, K., Sakaguchi, S., Shimizu, Y., Tamii, A., Tameshige, Y., Uchida, M., Uesaka, T., Yamada, T., Yoshida, H. P. |
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| Rok vydání: | 2021 |
| Předmět: | |
| Zdroj: | Prog. Theor. Exp. Phys. 2021, 093D01 |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1093/ptep/ptab102 |
| Popis: | We searched for the $\alpha$ condensed state in $^{13}$C by measuring the $\alpha$ inelastic scattering at $E_{\alpha} = 388$ MeV at forward angles including 0 degrees. We performed the distorted-wave Born-approximation calculation with the single-folding potential and the multipole decomposition analysis to determine the isoscalar transition strengths in $^{13}$C. We found a bump structure around $E_x = 12.5$ MeV due to the isoscalar monopole ($IS0$) transition. A peak-fit analysis suggested that this bump consisted of several $1/2^-$ states. We propose that this bump is due to the mirror state of the 13.5 MeV-state in $^{13}$N, which dominantly decays to the $\alpha$ condensed state in $^{12}$C. It was speculated that the $1/2^-$ states around $E_x = 12.5$ MeV were candidates for the $\alpha$ condensed state, but the $3\alpha + n$ orthogonality condition model suggests that the $\alpha$ condensed state is unlikely to emerge as the negative parity states. We also found two $1/2^+$ or $3/2^+$ states at $E_x = 14.5$ and 16.1 MeV excited with the isoscalar dipole ($IS1$) strengths. We suggest that the 16.1-MeV state is a possible candidate for the $\alpha$ condensed state predicted by the cluster-model calculations on the basis of the good correspondence between the experimental and calculated level structures. However, the theoretical $IS1$ transition strength for this state is significantly smaller than the measured value. Further experimental information is strongly desired to establish the $\alpha$ condensed state in $^{13}$C. Comment: 24 pages, 12 figures, published in PTEP |
| Databáze: | arXiv |
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