1. Decay study of $^{11}$Be with an Optical TPC detector
- Author
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Sokołowska, N., Guadilla, V., Mazzocchi, C., Ahmed, R., Borge, M., Cardella, G., Ciemny, A. A., Cosentino, L. G., De Filippo, E., Fedosseev, V., Fijałkowska, A., Fraile, L. M., Geraci, E., Giska, A., Gnoffo, B., Granados, C., Janas, Z., Janiak, Ł., Johnston, K., Kamiński, G., Korgul, A., Kubiela, A., Maiolino, C., Marsh, B., Martorana, N. S., Miernik, K., Molkanov, P., Ovejas, J. D., Pagano, E. V., Pirrone, S., Pomorski, M., Quynh, A. M., Riisager, K., Russo, A., Russotto, P., Świercz, A., Viñals, S., Wilkins, S., and Pfützner, M.
- Subjects
Nuclear Experiment - Abstract
The $\beta$ decay of one-neutron halo nucleus $^{11}$Be was investigated using the Warsaw Optical Time Projection Chamber (OTPC) detector to measure $\beta$-delayed charged particles. The results of two experiments are reported. In the first one, carried out in LNS Catania, the absolute branching ratio for $\beta$-delayed $\alpha$ emission was measured by counting incoming $^{11}$Be ions stopped in the detector and the observed decays with the emission of $\alpha$ particle. The result of 3.27(46)\% is in good agreement with the literature value. In the second experiment, performed at the HIE-ISOLDE facility at CERN, bunches containing several hundreds of $^{11}$Be ions were implanted into the OTPC detector followed by the detection of decays with the emission of charged particles. The energy spectrum of $\beta$-delayed $\alpha$ particles was determined in the full energy range. It was analysed in the R-matrix framework and was found to be consistent with the literature. The best description of the spectrum was obtained assuming that the two $3/2^+$ and one $1/2^+$ states in $^{11}$B are involved in the transition. The search for $\beta$-delayed emission of protons was undertaken. Only the upper limit for the branching ratio for this process of $(2.2 \pm 0.6_{\rm stat} \pm 0.6_{\rm sys}) \times 10^{-6}$ could be determined. This value is in conflict with the result published in [Ayyad et al. Phys. Rev. Lett. 123, 082501 (2019)] but does agree with the limit reported in [Riisager et al., Eur. Phys. J. A (2020) 56:100], Comment: 16 pages, 18 figures, submitted to Phys. Rev. C
- Published
- 2024