New Measurement of the $^{5}$H Ground State
ORAL
Abstract
We have studied the ground state of $^{5}$H using the $^{6}$He($d$,$^{3}$He)$^{5}$H reaction in inverse kinematics. Existing data for $^{5}$H are in conflict with each other and with many theoretical predictions. This measurement provides a clear evidence for the $^{5}$H ground state, and the previously unreported $^{6}$He($d$,$t)^{5}$He$_{g.s.}$ reaction is also observed. A $^{6}$He beam at 55 MeV/A produced at the National Superconducting Cyclotron Laboratory at Michigan State University bombarded a 1.9 mg/cm$^{2}$ (CD$_{2})_{n}$ target. The reaction products were detected with HiRA (the High Resolution Array). The $^{3}$He and $^{3}$H particles from the $^{6}$He($d$,$^{3}$He/$^{3}$H)$^{5}$H/$^{5}$He reactions were detected in coincidence with the decay products of the unstable $^{5}$H and $^{5}$He nuclei, providing signatures for the transitions of interest. The properties of the $^{5}$He ground state provide information about the calibration and response of the apparatus. Details of the measurement, and a comparison of the data with earlier results and theoretical calculations, will be presented.
*Work supported by the U.S. Department of Energy under Contracts DE-FG02-04ER41320 and DE-FG02-87ER40316, and the U. S. National Science Foundation under Grant Numbers PHY-1068217 and PHY-1068192.
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