First measurement of the 2.4 and 2.9 MeV ${}^6$He three-cluster resonant states via the ${}^3$H(${}^4$He,p$\alpha$)2n four-body reaction

Abstract

Two new low-lying ${}^6$He levels at excitation energies of about 2.4 and 2.9 MeV were observed in the experimental investigation of the p-$\alpha$ coincidence spectra obtained by the ${}^3$H(${}^4$He,p$\alpha$)2n four-body reaction at $E_{{}^4\mathrm{He}}$ beam energy of 27.2 MeV. The relevant $E^{\ast }$ peak energy and $\Gamma$ energy width spectroscopic parameters for such ${}^6$He${}^{\ast }$ excited states decaying into the $\alpha$+n+n channel were obtained by analyzing the bidimensional ($E_{\mathrm{p}}$, $E_{\alpha }$) energy spectra. The present new result of two low-lying ${}^6$He${}^{\ast }$ excited states above the ${}^4$He+2n threshold energy of 0.974 MeV is important for the investigation of the nuclear structure of neutron rich light nuclei and also as a basic test for theoretical models in the study of the three-cluster resonance feature of ${}^6$He.

16 pages, 7 figures, 2 tables, accepted for publication in Mod. Phys. Lett. A

References in corpus (3)

• Resonances of 7He in the complex scaling method
• Effective Interaction Techniques for the Gamow Shell Model
• Experimental evidence of the ${}^6$He level at $E^{\ast }$ = 18.3 MeV by the ${}^4$He+${}^3$H three-body reaction

Cited by in corpus (1)

• Validation of the ${}^{10}\mathrm{Be}$ Ground-State Molecular Structure Using ${}^{10}\mathrm{Be}(p,p\alpha {)}^6\mathrm{He}$ Triple Differential Reaction Cross-Section Measurements