Search for Gamow-Teller strength in the continuum via theHe3(n,p)3H reaction at 288 MeV
| Autor: | B. A. Brown, O. Häusser, A. Celler, A. Trudel, R.S. Henderson, S. Burzynski, K. P. Jackson, W. P. Alford, Michel Vetterli, B. W. Pointon, K. Hicks, Murray Moinester, S. Yen, D. Frekers, R. L. Helmer, C. A. Miller, R. Jeppesen, R. Abegg |
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| Rok vydání: | 1993 |
| Předmět: | |
| Zdroj: | Physical Review C. 47:1563-1570 |
| ISSN: | 1089-490X 0556-2813 |
| Popis: | Cross sections for the $^{3}\mathrm{He}$(n,p) reaction were measured at angles of 2.7\ifmmode^\circ\else\textdegree\fi{}, 7.5\ifmmode^\circ\else\textdegree\fi{}, 14.4\ifmmode^\circ\else\textdegree\fi{}, 28.2\ifmmode^\circ\else\textdegree\fi{}, and 34.9\ifmmode^\circ\else\textdegree\fi{} (c.m.) at an incident beam energy of 288 MeV. Outgoing protons were observed to energies corresponding to a Q value of -40 MeV. The reduced cross section for the Gamow-Teller component of the ground-state isobaric-analog transition was determined to be \ensuremath{\sigma}^=\ensuremath{\sigma}(q=0)/${\mathit{B}}_{\mathrm{GT}}$=6.9\ifmmode\pm\else\textpm\fi{}0.2 mb/sr. This value is significantly smaller than that observed for nuclei in the mass range 6\ensuremath{\le}A\ensuremath{\le}13. A multipole analysis of the data indicates that the cross section of the continuum up to a Q value of -20 MeV involves mainly \ensuremath{\Delta}L=1 spin dipole transitions. The analysis determines an upper limit of 0.06 units of Gamow-Teller strength in transitions to excited states between 7 and 16 MeV, but is consistent with no Gamow-Teller strength in this region. Distorted wave impulse approximation calculations using transition amplitudes from a large-scale shell model calculation provide a good fit to the measured ground-state cross section, but fail to account for the magnitude of the measured cross sections to the continuum below 30 MeV excitation. |
| Databáze: | OpenAIRE |
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