Parity Mixed Doublets in A = 36 Nuclei

Abstract

The $\gamma$-circular polarizations ($P_{\gamma }$) and asymmetries ($A_{\gamma }$) of the parity forbidden M1 + E2 $\gamma$-decays: ${}^{36}C{l}^{\ast }(J^{\pi }=2^{-};T=1;E_x=1.95$ MeV) $\to$ ${}^{36}Cl(J^{\pi }=2^{+};T=1;g.s.)$ and ${}^{36}A{r}^{\ast }(J^{\pi }=2^{-};T=0;E_x=4.97$ MeV) $\to$ ${}^{36}A{r}^{\ast }(J^{\pi }=2^{+};T=0;E_x=1.97$ MeV) are investigated theoretically. We use the recently proposed Warburton-Becker-Brown shell-model interaction. For the weak forces we discuss comparatively different weak interaction models based on different assumptions for evaluating the weak meson-hadron coupling constants. The results determine a range of $P_{\gamma }$ values from which we find the most probable values: $P_{\gamma }$ = $1.1\cdot 10^{-4}$ for ${}^{36}Cl$ and $P_{\gamma }$ = $3.5\cdot 10^{-4}$ for ${}^{36}Ar$.

Comments: RevTeX, 17 pages; to appear in Phys. Rev. C