Correlation studies of the $^{5}$H spectrum

The nuclear system $^{5}$H was studied using the $^{3}$H($t$,$p$)$^{5}$H transfer reaction at a laboratory energy of 57.7 MeV and small center of mass angles. The energy and angular correlations among the $^{5}$H decay fragments were obtained by complete kinematical reconstruction. A broad structure in the $^{5}$H missing mass spectrum above 2.5 MeV with a typical width of several MeV was identified as a mixture of $3/2^+$ and $5/2^+$ states. Analysis of interference patterns observed in the measured angular correlations disclosed the $1/2^+$ ground state of $^{5}$H concealed in the smooth missing mass spectrum. The deduced values for the resonance energy and width are $E_{\text{g.s.}}\approx 1.8$ MeV and $\Gamma_{\text{g.s.}\approx 1.3$ MeV. The estimated cross sections for population of the ground state and the doublet of excited states at $\theta_{\text{c.m.}}=5^{\circ}-10^{circ}$ are $150\pm 50$ $\mu$b/sr and $4.6\pm 2$ mb/sr, respectively.