  We obtained total radiation widths of s-wave resonances through R-matrix
analysis of 147Sm(n,gamma) cross-sections. Distributions of these widths differ
markedly for resonances below and above 300 eV, in stark contrast to
long-established theory. We show that this change, as well as a similar change
in the neutron-width distribution reported previously, are reflected in abrupt
increases in both the average 147Sm(n,gamma) cross section and fluctuations
about the average near 300 eV. Such effects could have important consequences
for applications such as nuclear astrophysics and nuclear criticality safety.
