Comparison Between Measured and Calculated Gamow-Teller Distributions and the Corresponding Electron Capture Rates for pf-shell Nuclei in Pre-supernova Stars

Modeling the evolution of core-collapse and thermonuclear supernovae requires determining the electron capture rates on pf-shell nuclei at astrophysical temperatures and densities. We present results of a systematic comparison of electron capture rates determined from experimental Gamow-Teller Strength (B(GT)) distributions to electron capture rates determined from B(GT) distributions calculated with a shell-model code using two different interaction Hamiltonians and from QRPA calculations. The comparisons presented in this work are for 13 stable pf-shell nuclei for which experimentally measured B(GT) distributions have been determined from charge-exchange and beta decay measurements.