Differential and total cross sections for the ${}_{}{}^7{}_{}{}^{}\mathrm{Li}$($\gamma$,$t$)${}_{}{}^4{}_{}{}^{}\mathrm{He}$ reaction were measured. Both real and virtual photons were used in the experiment and gave self-consistent results. The data show a broad resonance indicating the presence of positive parity states near 8 MeV excitation in ${}_{}{}^7{}_{}{}^{}\mathrm{Li}$. A calculation using an $\alpha$-${}_{}{}^3{}_{}{}^{}\mathrm{H}$ cluster model of ${}_{}{}^7{}_{}{}^{}\mathrm{Li}$ was also performed. Poor agreement is found between the calculation and experimental results.

NUCLEAR REACTIONS ${}_{}{}^7{}_{}{}^{}\mathrm{Li}$($\gamma$,$t$)${}_{}{}^4{}_{}{}^{}\mathrm{He}$, measured $\sigma (E;E_{\alpha },{\theta }_{\alpha })$ and (($E$;$E_t$,${\theta }_t$)) calculated ${}_{}{}^3{}_{}{}^{}\mathrm{H}$-$\alpha$ cluster model cross section.

• Received 23 July 1979

DOI:https://doi.org/10.1103/PhysRevC.20.2025