The authors measured the ratio of pi /sup +/ photoproduction cross sections for the /sup 1/H( gamma , pi /sup +/n) and /sup 6/Li( gamma , pi /sup +/)/sup 6/He reactions near threshold. The total cross-section for the latter reaction was found to be lower than current theoretical predictions.
Deutsch, J., Favart, D., Prieels, R., Van Ostaeyen, B., Audit, G., de Botton, N., Faure, J.-L., Schuhl, Cl., Tamas, G., & Tzara, C. (1974). Measurement of pion photoproduction at threshold on /sup 6/Li. Physical Review Letters, 33(5), 316-319. https://hdl.handle.net/2078.5/82179 (Original work published 1974)