Nucleargfactors of the212−and the292+states inAt211

The $g$ factors of the ${\frac{21}{2}}^{-}$ (1416.3 keV, $T_{\frac{1}{2}}=50\mathrm{}$ nsec) and the ${\frac{29}{2}}^{+}$ (2641.2 keV, $T_{\frac{1}{2}}=70\mathrm{}$ nsec) states in ${}_{}{}^{211}{}_{}{}^{}\mathrm{At}$ were measured by the time differential spin rotation method. The experimental results corrected for diamagnetic shielding and Knight shift are $g\left({\frac{21}{2}}^{-}\right)=+0.917\mathrm{}\pm 0.016$ and $g\left({\frac{29}{2}}^{+}\right)=+1.073\mathrm{}\pm 0.031$. The analysis yields an orbital $g$ factor of the proton $g_t=1.12\mathrm{}\pm 0.04$. The comparison with $g$ factors of other ${\left(h_{\frac{9}{2}}\right)}^n$ proton states in $N=126\mathrm{}$ isotones shows a significant deviation from the predicted blocking of core polarization.