Two-deuteron photodisintegration of4HeatEγ=150–250MeV
| Autor: | B. J. Rice, N. R. Kolb, G. A. Retzlaff, E. A. Wulf, R. S. Canon, H. R. Weller, Gerald Feldman, K. Keeter, D. M. Skopik, R. E. Pywell, C. Mueller |
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| Rok vydání: | 2000 |
| Předmět: | |
| Zdroj: | Physical Review C. 61 |
| ISSN: | 1089-490X 0556-2813 |
| DOI: | 10.1103/physrevc.61.064612 |
| Popis: | We have performed a measurement of the cross section for the ${}^{4}\mathrm{He}(\ensuremath{\gamma},dd)$ reaction with photon energies between 150 and 250 MeV. Both reaction particles were detected in coincidence. We obtained absolute cross sections at six angles and two energy bins (150\char21{}190 MeV and 190\char21{}250 MeV). A Legendre polynomial fit to the angular distribution shows a ${\mathrm{sin}}^{2}\ensuremath{\theta}$ distribution which suggests the isospin-forbidden $E1$ transition. However, a transition matrix element (TME) analysis using only strictly allowed transitions shows that the angular distribution can be described by just two TMEs: $E2$ s- and d-wave absorption on the D state of ${}^{4}\mathrm{He}.$ We performed an inverse direct-capture calculation in order to determine if the D state could contribute to such a high degree to the cross section. This calculation indicates that 90% of the cross section arises from absorption on the D state but fails to reproduce the observed ${\mathrm{sin}}^{2}\ensuremath{\theta}$ angular distribution. |
| Databáze: | OpenAIRE |
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