Gamow-Teller strength in the 54Fe(p,n)54Co reaction at 135 MeV.

The {sup 54}Fe({ital p},{ital n}){sup 54}Co reaction was studied at 135 MeV by the time-of-flight technique. Neutrons were detected with an energy resolution of 245 keV in large-volume, mean-timed counters at a flight path of 125 m. The forward-angle spectra are dominated by the excitation of 1{sup +} states with characteristic {Delta}{ital l}=0 angular distributions peaked at 0{degree}. The strengths of the 1{sup +} excitations are interpreted as being equivalent to Gamow-Teller (GT) strengths excited in beta decay. This strength is observed to be highly fragmented; GT strength is identified in more than 30 states. The {ital B}(GT{minus}) strength is obtained relative to the Fermi strength {ital B}(F) assumed to be concentrated in the 0{sup +}, isobaric-analog ground state. The total {ital B}(GT{minus}) strength observed in discrete states, combined with the {ital B}(GT+) strength obtained from the ({ital n},{ital p}) reaction, yields a lower limit of 48 percent of the 3({ital N}{minus}{ital Z}) sum rule. Inclusion of {Delta}{ital l}=0 strength in the background and continuum above a quasifree scattering background increases this lower limit to 73 percent. If one considers the {Delta}{ital l}=0 strength observed in the full background and continuum up to {ital E}{sub {ital x}}=25 MeV, the entiremore » sum rule may be satisfied. The observed distribution of GT strength is in good agreement with a truncated 1{ital f}-2{ital p} shell-model calculation.« less