The ${}^8$He and ${}^{10}$He spectra studied in the $(t$,$p)$ reaction

Abstract

The low-lying spectra of ${}^8$He and ${}^{10}$He nuclei were studied in the ${}^3$H(${}^6$He,$p$)${}^8$He and ${}^3$H(${}^8$He,$p$)${}^{10}$He transfer reactions. The $0^{+}$ ground state (g.s.) of ${}^8$He and excited states, $2^{+}$ at $3.6-3.9$ MeV and $(1^{+})$ at $5.3-5.5$ MeV, were populated with cross sections of 200, 100-250, and 90-125 $\mu$b/sr, respectively. Some evidence for ${}^8$He state at about 7.5 MeV is obtained. We discuss a possible nature of the near-threshold anomaly above 2.14 MeV in ${}^8$He and relate it to the population of a $1^{-}$ continuum (soft dipole excitation) with peak value at about 3 MeV. The lowest energy group of events in the ${}^{10}$He spectrum was observed at $\sim 3$ MeV with a cross section of $\sim 140$ $\mu$b/sr. We argue that this result is possibly consistent with the previously reported observation of ${}^{10}$He, in that case providing a new g.s. position for ${}^{10}$He at about 3 MeV.

18 pages, 8 figures, submitted to Phys. Lett. B

References in corpus (1)

• New insight into the low-energy ${}^9$He spectrum

Cited by in corpus (12)

• Five-body resonances of 8He using the complex scaling method
• Ab-initio coupled-cluster calculations of ground and dipole excited states in 8He
• Anomalous population of ${}^{10}$He states in reactions with ${}^{11}$Li
• Five-body resonances in ${}^8$He and ${}^8$C using the complex scaling method
• Mirror symmetry breaking in He isotopes and their mirror nuclei
• Structure of neutron-rich He $\Lambda$ hypernuclei using the cluster orbital shell model
• Modeling the electric dipole strength of neutron-rich ${}^8$He: Prediction of multineutron collective excitations
• Soft dipole resonance in neutron-rich ${}^8$He
• On the possible existence of a soft dipole mode in 8He
• Soft dipole resonance in ${}^8$C and its isospin symmetry with ${}^8$He
• Low-energy dipole strength in 8He
• Proton inelastic scattering reveals deformation in ${}^8$He