Data obtained by the associated production of Λ hypernuclei through the (${\mathrm{\pi }}^{+}$,${\mathit{K}}^{+}$) reaction are presented for a wide range of mass numbers. The special features which make this reaction useful are pointed out. The reaction is shown to be an excellent probe of Λ single-particle states, as demonstrated by the excitation of deeply bound states which are interpreted as the weak coupling of a Λ to neutron-hole states of the core. The Λ binding energies and ground-state production cross sections for ${}_{\mathrm{\Lambda }}{}^9{}_{}{}^{}\mathrm{Be}$, ${}_{\mathrm{\Lambda }}{}^{12}{}_{}{}^{}\mathrm{C}$, ${}_{\mathrm{\Lambda }}{}^{16}{}_{}{}^{}\mathrm{O}$, ${}_{\mathrm{\Lambda }}{}^{28}{}_{}{}^{}\mathrm{Si}$, ${}_{\mathrm{\Lambda }}{}^{40}{}_{}{}^{}\mathrm{Ca}$, ${}_{\mathrm{\Lambda }}{}^{51}{}_{}{}^{}\mathrm{V}$, and ${}_{\mathrm{\Lambda }}{}^{89}{}_{}{}^{}\mathrm{Y}$ are presented.

• Received 6 February 1991

DOI:https://doi.org/10.1103/PhysRevLett.66.2585