The ¹²C and ²⁰⁸Pb(p,²He) reactions at 390.6 MeV and the deeply bound pionic states

The spectra for the ¹²C and ²⁰⁸Pb(p,²He) reactions near the threshold for free π^- production have been measured at 0° with a 390.6 MeV proton beam. The spectrum for ¹²C shows no signature of pionic bound states, and is explained to be composed of a flat continuum and the contribution of the quasi-free π^- production process. For ²⁰⁸Pb, the spectrum shows contributions from π^- bound states in addition to the quasi-free process. Preliminary results of the cross sections are obtained for the elementary processes of pion production in the (p,²He) reaction.