Meson-exchange enhancement of the first-forbiddenYg96(0−)→96Zrg(0+)βtransition:βdecay of the low-spin isomer ofY96
| Autor: | J. A. Becker, H. Mach, J. A. Winger, R. F. Casten, E. K. Warburton, R. L. Gill, B. A. Brown |
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| Rok vydání: | 1990 |
| Předmět: | |
| Zdroj: | Physical Review C. 41:226-242 |
| ISSN: | 1089-490X 0556-2813 |
| DOI: | 10.1103/physrevc.41.226 |
| Popis: | We have investigated the ${0}^{\mathrm{\ensuremath{-}}}$ $^{96}\mathrm{Y}^{\mathrm{g}}$ \ensuremath{\beta} decay to the levels of $^{96}\mathrm{Zr}$. A detailed decay scheme comprised of 63 \ensuremath{\gamma} rays and 44 energy levels has been obtained from \ensuremath{\gamma} singles, \ensuremath{\gamma} multispectral scaling, and \ensuremath{\gamma}-\ensuremath{\gamma} and E0-\ensuremath{\gamma} coincidences. ${Q}_{\ensuremath{\beta}}$ was measured using the \ensuremath{\beta}-\ensuremath{\gamma} coincidence technique, while absolute E0 and \ensuremath{\gamma}-ray intensities were obtained from singles conversion electron and \ensuremath{\gamma}-ray spectra measured at beam saturation. The high sensitivity of the study was aimed at investigating the \ensuremath{\beta} feeding of levels with excitation enegy above 4 MeV. Although most of the new levels were found in this region, their total \ensuremath{\beta} feeding was found to be below 0.6%. The first-forbidden \ensuremath{\beta}-decay rate for ${0}^{\mathrm{\ensuremath{-}}}$ $^{96}\mathrm{Y}^{\mathrm{g}}$\ensuremath{\rightarrow}${0}^{+}$ $^{96}\mathrm{Zr}^{\mathrm{g}}$ has been calculated within the framework of the spherical shell model using a model space of \ensuremath{\pi}(0${\mathit{f}}_{7/2}$,0${\mathit{f}}_{5/2}$,1${\mathit{p}}_{3/2}$,1${\mathit{p}}_{1/2}$,0${\mathit{g}}_{9/2}$) 1${\mathit{p}}_{1/2}$,0${\mathit{g}}_{9/2}$)\ensuremath{\nu} (${0\mathrm{g}}_{7/2}$,1${\mathit{d}}_{5/2}$,1${\mathit{d}}_{3/2}$,2${\mathit{s}}_{1/2}$) with limitations on the orbit occupancies. Additional evidence for meson enhancement of the timelike component of the axial current is obtained; the meson-exchange enhancement factor was found to be 1.75\ifmmode\pm\else\textpm\fi{}0.30, where the uncertainty arises from the calculation. |
| Databáze: | OpenAIRE |
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