Resonant states in H7 : Experimental studies of the H2(He8,He3) reaction

• DOI: 10.1103/physrevc.103.044313
• Publication Date: 2021-04-13T17:12:55Z
• Authors: I. A. Muzalevskii; A. A. Bezbakh; E. Yu. Nikolskii; V. Chudoba; S. A. Krupko; S. G. Belogurov; D. Biare; A. S. Fomichev; E. M. Gazeeva; A. V. Gorshkov; L. V. Grigorenko; G. Kaminski; O. Kiselev; D. A. Kostyleva; M. Yu. Kozlov; B. Mauyey; I. Mukha; Yu. L. Parfenova; W. Piatek; A. M. Quynh; V. N. Schetinin; A. Serikov; S. I. Sidorchuk; P. G. Sharov; N. B. Shulgina; R. S. Slepnev; S. V. Stepantsov; A. Swiercz; P. Szymkiewicz; G. M. Ter-Akopian; R. Wolski; B. Zalewski; M. V. Zhukov
• Keywords: Center (category theory)

The extremely neutron-rich system $^{7}$H was studied in the direct $^2$H($^8$He,$^3$He)$^7$H transfer reaction with a 26 AMeV secondary $^{8}$He beam [Bezbakh et al., Phys. Rev. Lett. 124 (2020) 022502]. missing mass spectrum and center-of-mass (c.m.) angular distributions of $^{7}$H, as well momentum distribution $^{3}$H fragment frame, were constructed. In addition to investigation reported Ref. 022502], we carried out another experiment same but modified setup, which cross-checked by study $^2$H($^{10}$Be,$^3$He$)^{9}$Li reaction. A solid experimental evidence is provided that two resonant states are located its at 2.2(5) 5.5(3) MeV relative $^3$H+4$n$ decay threshold. Also, there indications 7.5(3) 11.0(3) present measured spectrum. Based on energy distributions, obtained for reaction, weakly populated peak ascribed $^7$H ground state. It highly plausible firmly ascertained state $5/2^+$ member excitation $5/2^+$-$3/2^+$ doublet, built $2^+$ configuration valence neutrons. supposed 7.5 can be this could not resolved Consequently, doublet members appeared 022502] single broad 6.5 peak.