New Probe of Line Broadening with Resolvable Fine Structure: The

A recently developed technique enables one to measure the relative sign of inelastic proton-channel amplitudes of resonances. Using this we have measured signs of 32 fine-structure levels in the vicinity of the 3/2/sup -/ analog state seen in the reaction /sup 44/Ca + p at E/sub p/ = 2.6 MeV. Thereby we construct a new type of datum, ''the off-diagonal strength function,'' and compare this with the prediction made by the theory of analog-state broadening. This prediction involves no unknown parameters, and so the degree of fit provides an excellent test of the theory.