The ({sup 7}Li,{sup 7}Be{gamma}) reaction and isovector spin strength in {sup 40}Ca

The {sup 40}Ca({sup 7}Li,{sup 7}Be{gamma}) reaction at {ital E}({sup 7}Li)/{ital A} = 70 MeV has been used to investigate isovector giant resonances and to measure the ratio of {Delta}{ital S}=1 to {Delta}{ital S}=0 spin strength in {sup 40}Ca at high excitation energy. In the singles spectrum, the analogue of the giant dipole resonance is observed. Another resonance is observed at {ital E}{sub {ital x}}{approx_equal}15 MeV in the residual nucleus, which we suggest is a collective 2{sup {minus}} state. The isovector spin transfer strength at high excitation for the calcium target is compared to that measured with a carbon target under the same experimental conditions. Although more spin transfer strength at high excitation is observed for the calcium target than for the carbon target, this only accounts in part for an apparent discrepancy between previous {sup 40}Ca({ital p}{searrow},{ital p}{searrow}{sup {prime}}) and {sup 12}C({sup 7}Li,{sup 7}Be) experiments. The general utility of the ({sup 7}Li, {sup 7}Be{gamma}) reaction is discussed. {copyright} {ital 1996 The American Physical Society.}