Observation of the $^7$H excited state

• Main Authors: Bezbakh, A. A, Chudoba, V, Krupko, S. A, Belogurov, S. G, Biare, D, Fomichev, A. S, Gazeeva, E. M, Gorshkov, A. V, Grigorenko, L. V, Kaminski, G, Kiselev, O, Kostyleva, D. A, Kozlov, M. Yu, Mauyey, B, Mukha, I, Muzalevskii, I. A, Nikolskii, E. Yu, Parfenova, Yu. L, Piatek, W, Quynh, A. M, Schetinin, V. N, Serikov, A, Sidorchuk, S. I, Sharov, P. G, Slepnev, R. S, Stepantsov, S. V, Swiercz, A, Szymkiewicz, P, Ter-Akopian, G. M, Wolski, R, Zalewski, B, Zhukov, M. V
• Format: Journal Article
• Language: English
• Published: 18.06.2019
• Subjects: Physics - Nuclear Experiment
• DOI: 10.48550/arxiv.1906.07818

Phys. Rev. Lett. 124, 022502 (2020) The $^7$H system was populated in the $^2$H($^8$He,$^3$He)$^7$H reaction with a 26 AMeV $^8$He beam. The $^{7}$H missing mass energy spectrum, the $^{3}$H energy and angular distributions in the $^7$H decay frame were reconstructed. The $^7$H missing mass spectrum shows a peak which can be interpreted either as unresolved $5/2^+$ and $3/2^+$ doublet or one of these states at 6.5(5) MeV. The data also provide indications on the $1/2^+$ ground state of $^7$H located at 2.0(5) MeV with quite a low population cross section of $\sim 10$ $\mu$b/sr within angular range $\theta_{\text{cm}} \simeq 6^{\circ} - 30^{\circ}$.