Study of hypernuclei by associated production

Abstract

Data obtained by the associated production of \ensuremath{\Lambda} hypernuclei through the (${\mathrm{\ensuremath{\pi}}}^{+}$,${\mathit{K}}^{+}$) 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 \ensuremath{\Lambda} single-particle states, as demonstrated by the excitation of deeply bound states which are interpreted as the weak coupling of a \ensuremath{\Lambda} to neutron-hole states of the core. The \ensuremath{\Lambda} binding energies and ground-state production cross sections for $_{\mathrm{\ensuremath{\Lambda}}}^{9}\mathrm{Be}$, $_{\mathrm{\ensuremath{\Lambda}}}^{12}\mathrm{C}$, $_{\mathrm{\ensuremath{\Lambda}}}^{16}\mathrm{O}$, $_{\mathrm{\ensuremath{\Lambda}}}^{28}\mathrm{Si}$, $_{\mathrm{\ensuremath{\Lambda}}}^{40}\mathrm{Ca}$, $_{\mathrm{\ensuremath{\Lambda}}}^{51}\mathrm{V}$, and $_{\mathrm{\ensuremath{\Lambda}}}^{89}\mathrm{Y}$ are presented.