Linear polarization–direction correlations in -ray scattering experiments
Department of Physics & Astronomy, University of North Carolina at Chapel Hill, 27599-3255, Chapel Hill, NC, USA
2 Triangle Universities Nuclear Laboratory (TUNL), Duke University, 27708, Durham, NC, USA
Accepted: 14 April 2021
Published online: 14 June 2021
Scattering measurements with incident linearly polarized rays provide information on spins, parities, and -ray multipolarity mixing coefficients, and, therefore, on the nuclear matrix elements involved in the transitions. We present the general formalism for analyzing the observed angular correlations. The expressions are used to compute three-dimensional radiation patterns, which are important tools for optimizing experimental setups. Frequently, -ray transitions can proceed via two multipolarities that mix coherently. In such cases, the relative phases of the nuclear matrix elements are important when comparing results from different measurements. We discuss different phase conventions that have been used in the literature and present their relationships. Finally, we propose a basic experimental geometry consisting of detectors located at four different spatial locations. For this geometry, we present the measured anisotropies of the emitted rays in graphical format as an aid in the data analysis.
© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2021