We have measured the widths of the 3/$2^{\mathrm{-}}$ ground states of ${}_{}{}^5{}_{}{}^{}\mathrm{He}$ and ${}_{}{}^5{}_{}{}^{}\mathrm{Li}$ using the ${}_{}{}^3{}_{}{}^{}\mathrm{H}$(d,γ${)}^5$He and the ${}_{}{}^3{}_{}{}^{}\mathrm{He}$(d,γ${)}^5$Li reactions at ${\mathit{E}}_{\mathit{d}}$=8.6 MeV. The γ-ray spectra were fitted with a convolution of the NaI line-shape response function, as measured with the ${}_{}{}^3{}_{}{}^{}\mathrm{H}$(p,γ${)}^4$He reaction, and a Breit-Wigner single-level expression. The widths extracted from the spectra were found to be ${\mathrm{\Gamma }}_{\mathit{n}}$=1.36±0.19 MeV for ${}_{}{}^5{}_{}{}^{}\mathrm{He}$, and ${\mathrm{\Gamma }}_{\mathit{p}}$=2.44±0.21 MeV for ${}_{}{}^5{}_{}{}^{}\mathrm{Li}$. These values, significantly different from previously quoted measurements, lead to reduced widths which are equal to within error, a result which is consistent with the charge-symmetry property of the nuclear force.

• Received 1 August 1990

DOI:https://doi.org/10.1103/PhysRevC.43.343