Résumé : The nuclear system H5 was studied using the H3(t,p)H5 transfer reaction at a laboratory energy of 57.7 MeV and small center of mass angles. The energy and angular correlations among the H5 decay fragments were obtained by complete kinematical reconstruction. A broad structure in the H5 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 H5 concealed in the smooth missing mass spectrum. The deduced values for the resonance energy and width are Eg.s. 1.8 MeV and Γg.s. 1.3 MeV. The estimated cross sections for population of the ground state and the doublet of excited states at θc.m.=5°-10° are 150±50 μb/sr and 4.6±2 mb/sr, respectively. © 2005 The American Physical Society.