Observation of the Sign of the Nuclear Quadrupole Interaction byβ−γDirectional Correlations

Abstract
We have demonstrated for the first time the possibility of determining the sign of the nuclear quadrupole interaction by βγ directional correlations in a noncubic single crystal. A simple time-differential measurement on the 828-keV level of In115 populated by the allowed (Gamow-Teller) β decay of Cd115 yields the value of the quadrupole interaction of this level in a single crystal of Cd metal to be e2qQh=+146(5) MHz.